SARMs in Sport: What the Research Says 2026

Updated September 2026. SARMs Store sells research compounds only. Nothing on this page is medical advice or an instruction for human use, and nothing here should be read as guidance for anyone subject to anti-doping rules.

In August 2019, days before a scheduled fight, the UFC welterweight Nate Diaz announced publicly that he had been notified of an adverse finding for a SARM. What followed is one of the clearest illustrations available of how modern anti-doping works, what contaminated supplements look like in practice, and why the analytical sensitivity that catches doping also catches people who were not doping.

What happened in the Diaz case

Diaz was enrolled in the UFC anti-doping programme, then administered by the United States Anti-Doping Agency. A sample returned a trace finding for LGD-4033, the SARM also known as ligandrol. Diaz went public immediately, saying he had taken nothing but supplements and that he would not fight under a cloud.

The investigation traced the finding to a vegan multivitamin product. Testing of sealed units of the same product identified LGD-4033 as a contaminant, at a concentration far too low to produce any physiological effect, in a product whose label made no mention of any SARM. USADA concluded that the finding was consistent with contamination rather than intentional use, issued no sanction, and Diaz fought Anthony Pettis at UFC 241 as scheduled.

Two details matter more than the headline. The first is quantity: amounts in cases of this type are typically in the picogram per millilitre range in urine, around a millionth of what a deliberate administration would produce. The second is the source: an ordinary multivitamin, not a specialist bodybuilding product, presumably contaminated through shared equipment or raw material handling somewhere in a contract manufacturing chain.

The wider contamination record

The Diaz case is not isolated, and the research literature explains why.

How common is contamination? The foundational work is Geyer and colleagues, reporting in the International Journal of Sports Medicine in 2004 on an International Olympic Committee funded study. Of 634 nutritional supplements bought in thirteen countries, around fifteen per cent contained anabolic androgenic steroids not declared on the label. That study reshaped how anti-doping organisations talk about supplements and it predates SARMs entirely.

How bad is it in the SARM category specifically? Van Wagoner and colleagues, publishing in JAMA in 2017, chemically analysed 44 products sold online as SARMs. Only about half contained the compound named on the label. Roughly two in five contained a different unapproved drug. Around one in ten contained no active compound at all. Amounts differed substantially from label claims in a large proportion. That is the single most useful citation in this whole subject.

Other athlete cases. Ostarine is the most frequently detected SARM in anti-doping and has appeared in numerous cases where contaminated supplements were accepted or argued as the source. The swimmer Madisyn Cox had a ban substantially reduced in 2018 after a contaminated multivitamin was identified as the source of a trace finding. In mixed martial arts, several athletes have received reduced sanctions after ostarine findings were traced to supplement products. Contamination defences have succeeded where the athlete could produce the actual product, sealed, for testing, and have failed where they could not. That is the practical lesson of the entire case history.

Detection windows

Detection is a function of laboratory sensitivity, not of the compound’s duration of effect, and modern accredited laboratories are extremely sensitive. Published detection window work and case experience indicate that SARM parent compounds and metabolites are detectable in urine for weeks after administration, and markedly longer where a sensitive method targets a long-lived metabolite. Hair analysis has also been applied in SARM cases and can extend the window considerably.

For trace contamination the picture is different and in some ways worse. A one-off ingestion of a contaminated product can produce a detectable finding for days, entirely disconnected from any performance benefit. Because strict liability applies, the athlete is responsible for the presence of the substance whatever its origin.

Why strict liability makes batch testing the only real answer

Under the World Anti-Doping Code, and therefore under UK Anti-Doping rules, an athlete is responsible for any prohibited substance found in their sample. Intent is not required for a violation; it is relevant only to the length of the sanction. To reduce a sanction on the basis of contamination, an athlete must establish the source on the balance of probabilities, which in practice means producing a sealed sample of the specific batch and having it independently analysed.

UK Anti-Doping’s published guidance is consistent on this. It does not promise that any supplement is safe. It advises athletes to assess the need for a supplement, to assess the risk, and where they proceed, to use products batch tested through a recognised programme such as Informed Sport, which tests sealed units from individual production batches against the prohibited list and retains those samples. That retention is the part that matters, because it is what allows a source to be established later.

SARMs are prohibited at all times under section S1.2 of the WADA Prohibited List as other anabolic agents. MK-677 is prohibited under section S2 as a growth hormone secretagogue. Aromatase inhibitors including arimistane sit under section S4.1. None of these are in-competition-only categories.

Legal status in the UK, 2026

SARMs are not controlled substances under the Misuse of Drugs Act 1971. Sold or advertised for human use they are unlicensed medicines, which the MHRA enforces, so they are supplied here strictly for laboratory research. Anabolic steroids, by contrast, are Class C under Schedule 4 Part 1, where possession for personal use is not an offence but supply and production are. None of this affects sporting eligibility, which is governed separately by the WADA Code and administered in the UK by UK Anti-Doping. A substance can be entirely lawful to possess and still end a career in sport.

How to check a supplier

For anyone in a tested sport the questions differ in emphasis. Does the manufacturer batch test through a recognised sports programme, and does it retain sealed samples from each batch? Is there a batch-specific certificate of analysis from an independent laboratory, identifying content by HPLC or LC-MS with a purity figure and a batch number matching the bottle? Is the facility used for products containing prohibited substances, and if so, what cross-contamination controls exist? Is manufacture in the UK, where the chain is shorter and auditable?

Dexterz Labs products are manufactured in the UK, and batch certificates of analysis are being published on the product page as testing is completed. That said, this page does not tell any athlete that a research compound or any supplement is safe to use under anti-doping rules. The compounds sold on this site are prohibited in sport and are sold for laboratory research only.

Frequently asked questions

Was Nate Diaz banned? No. USADA determined the LGD-4033 trace was consistent with contamination of a vegan multivitamin rather than intentional use, issued no sanction, and the fight went ahead.

How much SARM was in the product? Amounts in contamination cases of this kind are typically in the picogram per millilitre range in urine, orders of magnitude below any dose that could have an effect.

How common is supplement contamination? Geyer and colleagues found undeclared anabolic steroids in around fifteen per cent of 634 supplements in 2004. Van Wagoner and colleagues found fewer than half of products sold as SARMs contained the labelled compound in 2017.

How long are SARMs detectable? Weeks in urine in the published detection work, with longer windows for some metabolites and for hair analysis. Trace contamination can be detectable for days.

Does a contamination defence work? Only where the athlete can produce a sealed unit of the specific batch for independent analysis. Strict liability puts the burden on them.

What should a tested athlete do? Follow UK Anti-Doping guidance, assess whether a supplement is needed at all, and if proceeding use only batch-tested products from a recognised programme.

Added to basketBasket

SARMs in Sport: What the Research Says, UK 2026