Banned supplements and anti-doping risk

The rule that decides the case before the evidence

Start with the text, because every argument downstream is shaped by it. Article 2.1.1 of the 2021 World Anti-Doping Code reads:

It is the Athletes' personal duty to ensure that no Prohibited Substance enters their bodies. Athletes are responsible for any Prohibited Substance or its Metabolites or Markers found to be present in their Samples. Accordingly, it is not necessary that intent, Fault, Negligence or knowing Use on the Athlete's part be demonstrated in order to establish an anti-doping rule violation under Article 2.1.

The Code's own comment on that article names the doctrine: "An anti-doping rule violation is committed under this Article without regard to an Athlete's Fault. This rule has been referred to in various CAS decisions as 'Strict Liability'."

Read what that does and does not say. It does not say a contaminated athlete is a cheat. It says the finding is established by the presence of the substance, full stop, and that everything about how it got there belongs to a later stage — the sanction. Article 21.1.3 makes the same point as a duty rather than a rule: the athlete's responsibility is "to take responsibility, in the context of anti-doping, for what they ingest and Use."

The practical consequence is a reversal most people find counter-intuitive. Once a sample comes back adverse, nobody has to prove you did anything. You have to prove where it came from — and proving a negative about a tub you finished six weeks ago and threw away is close to impossible. Almost every contamination case that ends well ends well because the athlete still had the product, the batch number and the receipt.

This is not a peculiarity of the international system either. Nevada's own regulations restate it almost word for word for professional unarmed combat: "It is the duty of each unarmed combatant to ensure that no prohibited substance enters his or her body... it is not necessary to establish that the unarmed combatant intentionally, knowingly or negligently used a prohibited substance."

Which Prohibited List is in force, and how to check the right one

The Prohibited List currently in force is the 2026 List. WADA's Executive Committee approved it on 11 September 2025 and it entered into force on 1 January 2026. Do not take that from this page in a year's time: check it live.

The revision is annual and the cycle is fixed. WADA's List Expert Advisory Group begins reviewing in January, a draft circulates to stakeholders, the Health, Medical and Research Committee makes recommendations, the Executive Committee approves at its September meeting, and the List is published by 1 October to take effect the following 1 January. WADA states the reason for that three-month gap explicitly: so that athletes and their entourage can acquaint themselves with the modifications. In practice it means that for the last quarter of every year there are two lists in existence and only one of them is binding on you today.

For a substance or method to be added it must meet at least two of three criteria: it has the potential to enhance sport performance, it represents an actual or potential health risk to athletes, or it violates the spirit of sport.

The List itself has fourteen sections. S0 to S9 cover substances, M1 to M3 cover methods, and P1 covers beta-blockers in particular sports. S0 to S5 and M1 to M3 are prohibited at all times, in and out of competition; S6 to S9 are prohibited in competition only, where "in competition" means the period from 11:59 p.m. on the day before a competition you are scheduled to participate in, through the end of that competition and the related sample collection.

Two things on that page matter more than the substance names, and both are quoted from WADA directly. The first is that the List is not a closed set: "The fact that a substance is not on the Prohibited List does not mean that it is not prohibited since most categories only include some common examples and are not exhaustive." Section S0 exists precisely to catch pharmacological substances with no approval from any governmental regulatory health authority — drugs in development, discontinued drugs, designer drugs, veterinary drugs. BPC-157 sits there. So does 2,4-dinitrophenol.

The second is that the Specified/Non-Specified distinction, which fighters often read as "less serious", does nothing of the kind. WADA: "'Specified' substances or methods are not necessarily less effective doping agents than 'Non-Specified' ones, nor do they relieve athletes of the strict liability rule that makes them responsible for all substances that enter their body." The category exists to give a tribunal flexibility when sanctioning, and for no other purpose.

The changes for 2026 are mostly clarifications — further examples added to S1 anabolic agents, S2 peptide hormones, S4 hormone and metabolic modulators and S6 stimulants; a change to salmeterol's dosing intervals with the maximum daily dose unchanged; a note that sustained-release glucocorticoid formulations may remain detectable past the washout period. Two are substantive: the non-diagnostic use of carbon monoxide became a new prohibited method, M1.4, and cell components such as mitochondria and ribosomes were added to the gene and cell doping prohibition in M3.2.

To check a specific medication, use Global DRO, which is run as a partnership between Sport Integrity Canada, Swiss Sport Integrity, UK Anti-Doping and USADA, with the Japanese, Australian and New Zealand agencies as licensees. It answers for medications by brand and country. It does not answer for supplements, and it says so — that is a different problem with no equivalent tool.

S5: the category built around a weight-class athlete's worst week

Diuretics and masking agents are section S5, they are prohibited at all times, and every substance in the class is a Specified Substance. WADA's own wording is a blanket: "All diuretics and masking agents, including all optical isomers, e.g. d- and l- where relevant, are prohibited."

The named examples on the 2026 List include acetazolamide, amiloride, bumetanide, canrenone, chlortalidone, etacrynic acid, furosemide, indapamide, metolazone, spironolactone, the thiazides including hydrochlorothiazide, torasemide, triamterene and xipamide. Also listed: the vaptans (conivaptan, tolvaptan and relatives), desmopressin, probenecid, and plasma expanders by intravenous administration — albumin, dextran, hydroxyethyl starch and mannitol.

There is a short exceptions list and it is worth knowing exactly: drospirenone, pamabrom, topical ophthalmic carbonic anhydrase inhibitors such as dorzolamide and brinzolamide, and local felypressin in dental anaesthesia. Pamabrom in particular is sold over the counter for premenstrual fluid retention, and its being an exception rather than a prohibition is the kind of detail that gets repeated wrongly in both directions.

Two things make this class different for anyone who competes at a weight.

The first is that these are ordinary medicines. The UFC's own Prohibited List annotates S5 with the plain-language note that these substances may be found in medications used to treat heart failure and hypertension. A fighter in their thirties who gets put on a thiazide for blood pressure by a GP who has never heard of an athletic commission has a problem that has nothing to do with performance and everything to do with paperwork.

The second is that S5 has a trap attached that catches people who thought they were being careful. The List carries a note: where a threshold substance — formoterol, salbutamol, cathine, ephedrine, methylephedrine or pseudoephedrine — is detected together with a diuretic or masking agent, it is reported as an Adverse Analytical Finding unless the athlete holds a therapeutic use exemption for that substance in addition to one for the diuretic. One approved exemption is not enough. You need both.

And then there is the reason the class exists at all. Diuretics are prohibited not only because they can dilute a urine sample below the concentration at which other substances are reportable, but because losing water fast is itself the thing they do. That is exactly what a cut that has gone wrong wants. If you are looking for what the literature actually supports about the size and pace of a descent, that question has a published answer and none of it involves a prescription pad. Whatever else a diuretic does in that situation, it does not flush toxins — that phrase is marketing with no physiological basis behind it, and repeating it has never made a bad cut safer or a positive test go away.

How a fighter with no intent ends up with a prohibited substance in their urine

There are five recognised routes and they are not equally likely.

Cross-contamination in manufacturing. Geyer's group, reporting the largest international survey of the problem, suggested poor quality control and shared production lines as the most likely cause of what they found. A facility that runs a prohormone product on Monday and a protein blend on Tuesday transfers material at levels no consumer could detect and every doping laboratory can.

Deliberate spiking. Duiven's group found seven high-level findings across three products at concentrations that could not plausibly be cross-contamination — oxilofrine at 55 mg per gram in one case. They call the obvious explanation by its name: the deliberate addition of undeclared substances by a manufacturer. This is not contamination. It is adulteration, and the customer is the victim of it.

Mislabelling in both directions. USADA describes three patterns it has seen: labels listing a prohibited substance that testing does not find, labels listing nothing prohibited where testing finds something, and repeat testing of the same product returning different ingredients batch to batch.

Botanicals producing prohibited substances naturally. This is the one almost nobody plans for. USADA's list is specific: Cannabis sativa produces THC, ephedra produces ephedrine and pseudoephedrine, Citrus aurantium — bitter orange — produces octopamine, and Tinospora crispa produces higenamine, which is a prohibited beta-2 agonist. Duiven's group found higenamine in four products, all of which contained complex botanical ingredients, and could not distinguish natural presence from contamination.

Microbial conversion. The same paper raises the possibility that plant sterols in botanical raw materials are converted to low levels of anabolic steroids during processing, which would explain the pattern of boldione and 17α-AED findings they saw at low concentration across unrelated products.

Underneath all five sits the regulatory fact that makes them possible. USADA states it directly: dietary supplements are regulated in a post-market fashion, meaning no regulatory body approves the accuracy of the label or the safety of the contents before they are sold. The 2026 National Athletic Trainers' Association position statement puts the same thing in one clause — while the market continues to expand, the quality of dietary supplements worldwide is poorly regulated.

And the amounts required are tiny. Geyer's group demonstrated that supplements containing nandrolone prohormones adding up to a total intake of more than one microgram produced positive results for norandrosterone for several hours. Duiven's paper notes that laboratories have reported limits of detection as low as two picograms per millilitre. There is no threshold of carelessness below which a contaminated product becomes harmless, because the analytical sensitivity is orders of magnitude beyond anything a manufacturer's cleaning schedule was designed around.

The contamination numbers, and what each one actually measured

Three studies do most of the work in this field. All three are real, all three are frequently misquoted, and the misquotation is always in the same direction — a figure measured on a deliberately risky subset gets repeated as though it described the shelf in your local shop.

Geyer et al., 2004 — 14.8%. Between October 2000 and November 2001, researchers at the German Sport University Cologne bought 634 non-hormonal nutritional supplements in 13 countries from 215 different suppliers, 91.2% from shops and 8.2% online, and analysed them by gas chromatography–mass spectrometry for eleven anabolic androgenic steroids. Ninety-four samples — 14.8% — contained steroids not declared on the label. Sixty-six samples (10.4%) gave no reliable data because of matrix effects. The split by supplier is the part that gets dropped: 21.1% of supplements from companies that also sold prohormones were positive, against 9.6% from companies that did not. Concentrations ranged from 0.01 to 190 micrograms per gram. This remains the largest and most geographically representative sample anyone has published. It is also, now, a study of a market that existed twenty-five years ago and before the US Anabolic Steroid Control Act of 2004.

Judkins, Hall and Hoffman, 2007 — 25%. This is the origin of "one in four supplements contains a steroid", and it deserves to be described precisely because it is almost never described at all. Between July 2006 and January 2007, HFL Ltd bought 58 supplements from US retail outlets and internet sites. Of the 52 that could be analysed successfully by GCMS, 13 showed steroid contamination — 25.0%. Of the 54 analysed successfully by LCMS, 6 showed stimulant contamination — 11.1%. Testosterone boosters were the worst category at 6 of 9 products. Now the qualifications. The sample was not random: the report states that "products were selected from manufacturers who were not believed to regularly carry out banned substance screening as part of their routine quality control processes." The denominator for the headline figure is 52. It is a company report, not a peer-reviewed paper. And HFL Sport Science subsequently became part of LGC, the group that operates the Informed Sport certification programme — meaning the most-quoted contamination statistic in the industry was published by a laboratory that sells the remedy. That does not make the measurement wrong. It does mean it should never be cited without that sentence attached.

Duiven et al., 2021 — 38%. Sixty-six sports nutrition supplements from 21 brands were bought from 17 Dutch web shops in December 2014 and analysed by LGC under an extended ISO 17025 screen. Twenty-five products (38%) contained undeclared doping substances, 38 (58%) did not, and three (4.5%) were inconclusive. The findings included oxilofrine, BMPEA, NBDMPEA, DMAA, the anabolic steroids boldione and 17α-AED, the beta-2 agonist higenamine and the beta-blocker bisoprolol. The selection was explicitly purposive: products "identified as potentially high-risk" because they claimed to modulate hormone regulation, build muscle, increase fat loss or boost energy. The authors also record something that ought to make anyone quoting the figure careful — they applied minimum reporting levels for substances associated with natural presence and microbial conversion, and without those the total would have been 50%.

Two comparisons follow, and both cut against the story people usually tell with these numbers. Duiven's own comparison table puts the all-substance positive rate at 15% for Geyer, 24% for Judkins and 38% for their own study. It looks like a trend. The authors say it is not: chi-squared testing does not support a deterioration, and they attribute the difference to a broader analytical screen and a stronger focus on selecting performance-claim products. Their conclusion is the honest one, and it is narrower than the headline: the sports supplement industry does not appear to be solving its contamination and spiking problem.

The figures we will not print as fact

Four numbers circulate constantly in combat sports and none of them survives being chased to its source.

"Ten to fifteen percent of supplements contain prohibited substances." This traces to a framing sentence in Outram and Stewart's 2015 review, which states that available data indicate between 40 and 70% of athletes use supplements and that between 10 and 15% of supplements may contain prohibited substances. That is a summary of heterogeneous prevalence studies with incompatible sampling frames, offered as context for a paper about how badly the problem is measured. It is not a market prevalence rate and the authors do not present it as one.

"Up to nine percent of positive doping tests are caused by supplements." This is the most quotable and the least supportable. It reaches most readers via Duiven's introduction, which cites Outram and Stewart. Go to the original and the authors say the opposite of what the citation implies: they present indications ranging from 6.4% to 8.8%, then state that "such percentages are not comparable; instead they are provided as indications as to how difficult it is to ascertain or estimate the scale of this problem," and conclude that "it is currently not possible to quantify the scale of the problem." A number whose own authors published it as a demonstration that the number cannot be known is not a statistic. We will not print it as one.

"One in four supplements contains a banned steroid." Traced above: a 2007 company report, n=52 successfully analysed, deliberately sampled away from manufacturers who screen, purchases now nearly twenty years old, never peer-reviewed, published by a laboratory whose business is supplement certification. It is a legitimate finding about a deliberately risky subset in one market at one moment. As a description of what is on a shelf today it is untraceable, and we refuse it.

"Thirty-eight percent of supplements are contaminated." A misquotation of Duiven by removal of four words. The 38% describes a purposively selected high-risk subset. Applied to supplements in general it is simply wrong, and it is wrong in the direction that sells certification.

There is a fifth thing worth refusing, and it is not a number. There is no such thing as a WADA-approved or UKAD-approved supplement. UK Anti-Doping states it flatly: no anti-doping organisation is able to endorse or approve supplement products, and "if a company claims their product has been approved and/or certified by WADA or UKAD, this statement is inaccurate." USADA says the same about itself — it "does not evaluate, certify, approve, or endorse any dietary supplement or any dietary supplement company." Any product marketing that says otherwise has told you something checkable and false about itself, which is information about the manufacturer.

What third-party certification actually does

Certification is worth using. It is also routinely described as something it is not, including by people selling it, so here is what the programmes say about themselves.

Informed Sport, run by LGC and developed in 2008 with UK Anti-Doping, tests every single batch of a product before release to market, including every flavour and variant, using an ISO/IEC 17025 accredited screen for more than 285 substances, with post-certification blind purchases from retail as a further check. Batch numbers are searchable on their site and app.

Informed Choice, from the same laboratory and established in 2007, is a retail monitoring programme rather than a batch programme. At least twelve lots per year are bought blind from retail and tested. LGC states the limitation itself: "unlike Informed Sport, it is not guaranteed that every batch has been tested."

NSF Certified for Sport verifies that products do not contain any of 290 substances banned by major athletic organisations, that the contents match the label, that there are no unsafe levels of contaminants in the tested products, and that manufacture happens in a GMP-certified facility audited annually or bi-annually. Production lots are tested for banned substances. NSF describes itself as the only independent third-party certification recognised by USADA, MLB, the NHL and the CFL, and USADA confirms that from its side: it "currently recognizes NSF Certified for Sport as the program best suited for athletes to reduce the risk from supplements."

Now the limits, which are the part worth memorising.

Certification is a statement about a batch, not a brand. If the batch number on your tub is not the batch number in the database, you are holding an uncertified product made by a certified company. UKAD's instruction is explicit: only use batch-tested products, and "make sure you check the actual batch numbers prior to use."

Certification is a statement about a screen, not about everything. A screen for 285 or 290 substances is a screen for 285 or 290 substances. The Prohibited List's categories are open-ended by design, and new compounds appear in the supplement market before they are characterised.

Certification is a statement about a detection limit, not about zero. Product screens report contamination in nanograms per gram. Doping laboratories detect metabolites in urine at picograms per millilitre. Duiven's group put the practical implication carefully — testing supplements at 10 to 100 nanograms per gram is "a good measure for elite athletes to mitigate the risk". Mitigate, not remove.

And certification does not change strict liability. UKAD: "There are no guarantees that any supplement product is free from banned substances." USADA: "no dietary supplement can be guaranteed to be 100 percent risk-free." Both organisations recommend certified products anyway, which is the right position — a risk reduced by an order of magnitude is worth having, and pretending it is a risk removed is how people stop keeping receipts.

Which schemes count is a separate question with a genuinely different answer depending on who tests you, and that is the next section.

Who is actually testing you, and whose rules apply

This is where combat sports diverge from every other sport, and where generic anti-doping advice becomes dangerous. A boxer, a UFC fighter, an IBJJF competitor and an Olympic-pathway wrestler are under four different systems with four different lists, four different sanctioning ranges and four different attitudes to contaminated supplements.

Olympic-pathway amateur combat sports run under the Code. The International Judo Federation and United World Wrestling are Code signatories as ASOIF members; World Boxing, the International Boxing Association, the International Mixed Martial Arts Federation and the Global Association of Mixed Martial Arts all appear on WADA's signatory list too. For athletes in these systems, the Code and the current Prohibited List are the operative documents, testing and results management run through the international federation or the national anti-doping organisation, and the sanction for presence of a non-specified substance starts at four years unless the athlete establishes that the violation was not intentional, in which case it is two.

Professional boxing and MMA in the United States run under state athletic commissions, and the Code does not apply to them. Some commissions nonetheless import WADA's documents wholesale. Nevada does: NAC 467.011 adopts by reference the most recent version of the Prohibited List, the International Standard for Laboratories and WADA's Technical Documents, and NAC 467.00307 defines a prohibited substance as anything identified as prohibited on that List. So the list is the same. Almost nothing else is. A presence violation in Nevada carries ineligibility to compete in that state of at least 9 months and not more than 24, plus a fine of 15 to 30% of the purse. That is a different instrument from a four-year global ineligibility, and it is decided by a commission exercising discretion, not by a Code tribunal.

The UFC runs its own programme, and its rules on supplements are materially more generous than the Code's. Since 2024 the UFC Anti-Doping Policy has been administered independently by Combat Sports Anti-Doping, with sample collection by Drug Free Sport International. It has its own Prohibited List, effective 1 January 2024, which incorporates the WADA List but states that "where there is a conflict, the UFC Prohibited List shall apply." The differences are real: S8 is intentionally blank, so cannabinoids are not on the UFC list; higenamine is prohibited in competition only rather than at all times; and the policy sets Decision Concentration Levels — 0.10 ng/mL for clomifene, for SARMs, for GW-1516 and for the DHCMT long-term metabolite, 0.20 ng/mL for epitrenbolone — below which findings are handled as Atypical rather than Adverse.

Most importantly, the UFC list defines "Certified Supplements" as those certified by NSF Certified for Sport, Kölner Liste, Informed Sport, Informed Choice, HASTA, BSCG, or any other certifier endorsed by a national anti-doping organisation and agreed with the independent administrator. And Article 10.3.2 of the policy says that an athlete who demonstrates by clear and convincing evidence that a finding was caused by a Contaminated Product or a Certified Supplement bears No Fault or Negligence, and that in such a case there is no anti-doping policy violation at all — though they cannot compete until follow-up testing shows the substance is gone or below the applicable decision level. The UFC's own supplements page states the consequence in the bluntest terms available: approved supplements "should be the only supplements you use. You will be protected should any issues result from using these supplements. If you use supplements other than those below, you are NOT protected."

Set that against the Code, where the same proof gets you a reduction to somewhere between a reprimand and two years and the violation still exists. Same fighter, same tub, two different outcomes depending on the letterhead.

And the systems stack. The UFC's Prohibited List says so itself: athletes "may be subject to separate prohibited lists under the various Athletic Commission jurisdictions where UFC events are held" and are responsible for knowing both. A fighter can be cleared under a promotion's policy and still face a commission, or the reverse.

Grappling sits somewhere else again. The IBJJF states that it is not a signatory to the Code but abides by the Code and the Prohibited List, and has engaged USADA to conduct doping control at its events — sample collection, analysis, results management and adjudication. An athlete who tests positive at an IBJJF event is provisionally suspended in most cases from IBJJF events and from events run by Code signatories while the case is pending.

Professional boxing has a voluntary layer. The Voluntary Anti-Doping Association is a non-profit that fighters and promoters opt into, precisely because — in VADA's own description — combat sports are regulated at state level and commission testing "is often limited, predictable, or inconsistent". Enrolled athletes accept unannounced testing at any time in the eight weeks before competition, provide daily whereabouts, and agree that results go straight to the governing commission. If your bout agreement puts you in a VADA programme, that is an additional set of obligations on top of the commission's, not a substitute for them.

The rule to take from all of this is short. Before you take anything, find out which body governs the specific bout you are preparing for, and read that body's own document. The rules and commissions material is where the jurisdictional questions live; the substance questions are on this page; and the two have to be answered together because neither is sufficient alone.

When contamination helps you, and when it barely does

Under the WADA Code, "Contaminated Product" is a defined term and the definition is narrower than the ordinary meaning: "A product that contains a Prohibited Substance that is not disclosed on the product label or in information available in a reasonable Internet search."

That second clause does a great deal of work. If the substance in your sample has been publicly associated with that product — a warning letter, a forum thread with a lab report, an anti-doping organisation's high-risk list — the product may not qualify as contaminated at all under the Code, because the information was available and you did not find it. UKAD states the corresponding obligation as a requirement rather than good practice: all athletes must undertake thorough internet research prior to using any supplement product, and "not knowing is not an excuse."

If the product does qualify, Article 10.6.1.2 gives a sanction range of a reprimand with no ineligibility at the bottom and two years at the top, depending on degree of fault. But the article requires two separate things to be established, not one: that the substance came from a contaminated product, and, independently, No Significant Fault or Negligence. And the Code's own commentary warns how that plays out in practice: "The sanction reduction based on No Significant Fault or Negligence has rarely been applied in Contaminated Product cases unless the Athlete has exercised a high level of caution before taking the Contaminated Product."

The same commentary then tells you what caution looks like in evidence. It says that in assessing whether the athlete can establish the source, "it would, for example, be significant for purposes of establishing whether the Athlete actually Used the Contaminated Product, whether the Athlete had declared the product which was subsequently determined to be contaminated on the Doping Control form."

Nevada makes the same point as a rule rather than a comment. Its mitigating-circumstances regulation lists as a qualifying circumstance a violation resulting from a supplement containing a prohibited substance not disclosed on the label or in a reasonable internet search — but only "if the use of the supplement, vitamin or other product was disclosed on the prefight questionnaire completed by the unarmed combatant or was otherwise disclosed to a representative of the Commission." No prior disclosure, no mitigation.

Write that on the inside of the supplement cupboard. The declaration you make before anything goes wrong is the evidence you will be judged on afterwards.

Therapeutic use exemptions

A therapeutic use exemption authorises the use of a prohibited substance or method for a diagnosed medical condition without that use constituting a violation. It is not a formality and it is not a loophole; it is a medical file reviewed by a committee of physicians.

Four criteria in Article 4.2 of the International Standard for Therapeutic Use Exemptions must all be met, as the Athletics Integrity Unit states them: the athlete has a clear diagnosed medical condition requiring treatment with the prohibited substance or method; the therapeutic use will not, on the balance of probabilities, produce significant enhancement of performance beyond the athlete's normal state of health; the substance or method is an indicated treatment and there is no reasonable permitted therapeutic alternative; and the necessity does not arise from prior use, without an exemption, of something that was prohibited at the time.

Where you apply depends on your level. Under Code Article 4.4.2, athletes who are not international-level apply to their national anti-doping organisation; under 4.4.3, international-level athletes apply to their international federation. Under 4.4.4, a major event organiser may require its own exemption for its event, effective for that event only, and must recognise an existing valid one unless it explains its reasons for refusing.

Two combat-sports-specific warnings. First, a promotion or a commission runs its own process — the UFC publishes a separate therapeutic use exemptions document alongside its policy — so an exemption granted by one body is not automatically portable to another. Ask, in writing, before you assume. Second, retroactive exemptions exist but are narrow: USADA's policy allows retroactive consideration where emergency or urgent treatment was necessary, or where there was insufficient time or exceptional circumstances preventing a prospective application, and the athlete must still meet the same four conditions.

For a weight-class athlete the relevant collision is with S5. If you have a legitimate clinical reason to be on a diuretic, that is a TUE conversation with a physician and your anti-doping organisation months before a bout — and remember the List's note that a diuretic exemption does not cover a threshold substance found alongside it.

Before you are tested, and while you are being tested

Before. Assess the need before the risk: UKAD's framing is need, risk, consequence, in that order, and the first question is whether you need the product at all. Check every medication on Global DRO for the country you are in. Check every supplement against your governing body's own recognised certification schemes, not a generic list. Verify the actual batch or lot number in the certifier's database rather than trusting the logo on the tub. Keep the container, the batch number and the receipt until well after the fight — this is the single cheapest thing on the list and the one that most often decides cases. Write down what you take and when. The trend and the log are the part of preparation you control; that is the same discipline that makes a fight-camp nutrition plan worth anything, and it happens to double as evidence.

During. The process is standardised and worth knowing before you meet it. UK Anti-Doping's description of it runs as follows: doping control personnel notify you and show identification, you are told your rights and responsibilities, you sign the doping control form to confirm notification, and from that moment you are chaperoned and must remain in direct observation. You may request a delay for permitted reasons — finishing a competition, media commitments, a warm-down, medical treatment, locating a representative or interpreter, obtaining photo identification. You choose a sealed collection kit and should check it has not been tampered with. A urine sample requires a minimum of 90 ml, split into B and A bottles, B first. You seal the bottles and check that the codes on bottles, lids, stickers and box match. The sample's specific gravity is checked, and if it is out of range you provide another.

Three things in that process are load-bearing for a fighter specifically.

Declare everything. You will be asked to record any medications and supplements taken in the last seven days. That declaration is the evidence the Code's commentary and Nevada's regulations both treat as significant. Do not round it down and do not leave out the thing you are slightly embarrassed about.

Do not overhydrate. UKAD warns against it explicitly: it does not speed anything up, and a sample too dilute to analyse means providing another. A fighter who has just spent eighteen hours rehydrating after a weigh-in is the athlete most likely to fall foul of this, and it is worth planning for if you know testing follows the bout. What rehydration should actually look like is its own subject, and doping control is a constraint on it rather than an afterthought.

Take the test. Refusing or evading collection is itself a violation. UKAD notes it can lead to a four-year ban; Nevada sets refusal at 12 to 24 months of ineligibility in-state plus a fine of 20 to 40% of the purse. There is no version of declining that is better than complying and arguing afterwards. You may take a representative with you, and you should.

Keep your copy of the doping control form. Samples can be stored for up to ten years and re-analysed.

The gaps that matter to combat sports specifically

None of the contamination research above was done on fighters.

The prevalence studies sampled supplement markets, not athlete populations, and the products they selected were chosen for risk characteristics — hormone claims, muscle claims, fat-loss claims, energy claims — that overlap with what fighters buy but were never defined by it. There is no published prevalence study of contamination in the specific products marketed to combat-sport athletes, and there is no published figure for how many combat-sport positives are attributable to contamination, in any promotion, commission or federation.

The dates matter too. Geyer's purchases were made in 2000 and 2001. The HFL report's were made in 2006 and 2007. Duiven's were made in December 2014 and published in 2021. The most recent market-wide prevalence figure available in the peer-reviewed literature describes purchases made more than a decade ago, and the market has changed — new compounds, new sales channels, more certification, and more direct-to-consumer sellers outside any of it.

Finally, the population caveat that applies across this whole site applies here as well. The sports-supplement literature is dominated by adult men, and the fighter population it is applied to includes women, teenagers in wrestling and judo programmes, and amateurs with no anti-doping education at all — the group most likely to buy a fat burner off an advert and least likely to have anyone to ask. For a first-time amateur, the useful advice is not a better product. It is that the risk of the product is a risk you are taking for a benefit you probably cannot demonstrate.

What we could not verify

An article that quotes this precisely owes its gaps.

• The rate at which contaminated supplements cause positive tests. No authoritative figure exists. The one usually offered comes from a paper whose authors explicitly say the scale cannot be quantified. Anyone quoting you a percentage should be asked which study, which denominator and which year.
• Current market-wide contamination prevalence. We located no peer-reviewed prevalence study using purchases made after 2014. Every percentage in this article describes a market that no longer exists in the form that was sampled.
• The ISTUE text itself. WADA's International Standard for Therapeutic Use Exemptions would not serve to us directly. The four criteria here are as stated by the Athletics Integrity Unit, referencing ISTUE Article 4.2, and cross-checked against USADA's TUE Policy, which incorporates the Standard. Read WADA's own document before relying on it.
• The 2027 Code. The 2021 Code is in force as this is published. A 2027 Code and revised International Standards were approved in Busan in December 2025 and come into force on 1 January 2027, and reporting on the final drafts indicates the "Contaminated Product" concept is replaced by a broader "Contaminated Source". We have not read the final adopted text and are not describing its contents as rules. If you are reading this in 2027 or later, the sanctioning sections above may have been superseded.
• Whether the Prohibited List quoted here is still current. It was the 2026 List on 24 August 2026. The 2027 List is due for publication by 1 October 2026 and would take effect on 1 January 2027. Check the live page.
• Any individual product. We tested nothing, and we name no product as clean or contaminated. Neither should anyone else without a laboratory report for your batch.
• Your jurisdiction. Commission regulations are amended. Promotion policies are amended. The Nevada provisions cited here were added in 2016 and amended in 2019; verify the current text with the body sanctioning your bout.

Sources

Sourced to

1. The Prohibited List — World Anti-Doping Agency, 2026 List in force from 1 January 2026, accessed 24 August 2026
2. WADA publishes 2026 Prohibited List — World Anti-Doping Agency, news release, 30 September 2025
3. World Anti-Doping Code 2021 — World Anti-Doping Agency, in force from 1 January 2021 (PDF, mirrored by USADA)
4. Code Signatories — World Anti-Doping Agency, accessed 24 August 2026
5. Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids — results of an international study — Geyer H, Parr MK, Mareck U, Reinhart U, Schrader Y, Schänzer W, International Journal of Sports Medicine, February 2004;25(2):124-9. DOI 10.1055/s-2004-819955, PMID 14986195
6. Undeclared Doping Substances are Highly Prevalent in Commercial Sports Nutrition Supplements — Duiven E, van Loon LJC, Spruijt L, Koert W, de Hon OM, Journal of Sports Science and Medicine, 22 March 2021;20(2):328-338. DOI 10.52082/jssm.2021.328
7. Doping through supplement use: a review of the available empirical data — Outram S, Stewart B, International Journal of Sport Nutrition and Exercise Metabolism, February 2015;25(1):54-9. DOI 10.1123/ijsnem.2013-0174, PMID 25722470
8. Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With US Food and Drug Administration Warnings — Tucker J, Fischer T, Upjohn L, Mazzera D, Kumar M, JAMA Network Open, 5 October 2018;1(6):e183337. DOI 10.1001/jamanetworkopen.2018.3337, PMID 30646238
9. National Athletic Trainers' Association Position Statement: Evaluation of Dietary Supplements for Athlete Safety and Performance — Knappenberger K, Buell J, Wardenaar F, Weidman C, White D, Wright K, Journal of Athletic Training, August 2026;61(8):525-542. DOI 10.4085/1062-6050-0231.24, PMID 42564675
10. Investigation into supplement contamination levels in the US market — Judkins C, Hall D, Hoffman K, HFL Ltd company report, 2007 — not peer-reviewed; mirrored copy, cited here as the traceable origin of the "one in four" figure
11. Managing Supplement Risks — UK Anti-Doping, accessed 24 August 2026
12. The Testing Process — UK Anti-Doping, accessed 24 August 2026
13. Supplement Connect — U.S. Anti-Doping Agency, accessed 24 August 2026
14. TUE Policy of the United States Anti-Doping Agency — U.S. Anti-Doping Agency, incorporating the WADA International Standard for Therapeutic Use Exemptions
15. Therapeutic Use Exemptions — Athletics Integrity Unit, stating the four ISTUE Article 4.2 criteria, accessed 24 August 2026
16. What Our Mark Means — Certified for Sport — NSF, accessed 24 August 2026
17. Informed Sport vs Informed Choice — LGC Group, accessed 24 August 2026 — certifier's own description of its programmes
18. UFC Prohibited List — Ultimate Fighting Championship, effective 1 January 2024 (PDF linked from ufcantidoping.com)
19. UFC Anti-Doping Policy — Ultimate Fighting Championship, effective 1 January 2024 (PDF linked from ufcantidoping.com)
20. UFC Anti-Doping: Approved Supplements — Ultimate Fighting Championship and Combat Sports Anti-Doping, accessed 24 August 2026
21. Nevada Administrative Code Chapter 467: Unarmed Combat — Nevada Legislative Counsel Bureau; anti-doping provisions added by R062-16 (effective 9 September 2016) and amended by R032-18 (effective 30 January 2019)
22. Anti-doping — International Brazilian Jiu-Jitsu Federation, accessed 24 August 2026
23. Voluntary Anti-Doping Association — VADA, accessed 24 August 2026
24. Global DRO — Global Drug Reference Online, a partnership of Sport Integrity Canada, Swiss Sport Integrity, UK Anti-Doping and USADA, accessed 24 August 2026

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