Selective androgen receptor modulators (SARMs)

The World Anti-Doping Agency (WADA) has specifically banned the class of selective androgen receptor modulators (SARMs) effective January 1, 2008.

According to the regulations, this group of substances is listed in Subgroup 2, “Other Anabolic Substances,” of Group S1, “Anabolic Agents.”

Testing methods for this group have already been developed at the Center for Preventive Doping Research at the German Sport University Cologne.

With regard to the chemical structure of Ostarin—currently the most advanced SARM (clinical Phase II in 2009)—and the structurally similar, medically unapproved SARM Andarin (S-4), confusion has repeatedly arisen in the literature, with S-4, for example, being incorrectly referred to as Ostarin and the structural formulas of both compounds being misattributed.

The exact structural formulas for Andarin and Ostarin (S-22) are shown on the side.

GTx provides the following information on the compound, referring to the active ingredient as Enobosarm (as of Oct. 31, 2012):

"GTx is developing enobosarm (Ostarine®; GTx-024), a selective androgen receptor modulator, or SARM, for the prevention and treatment of muscle loss in patients with non-small cell lung cancer and for other muscle wasting diseases."

It is assumed that enobosarm corresponds to the substance S-22. While Ostarine is not yet commercially available as a medication, Andarin was first illegally offered and sold on the internet in September 2009. A report on this, including the corresponding structural evidence, was published shortly thereafter (Thevis et al. 2009).

WADA Prohibited List

(January 2021) 

S1 ANABOLIC AGENTS

1. Anabolic Androgenic Steroids (AAS)

2. Other Anabolic Agents
Including, but not limited to:
Clenbuterol,
selective androgen receptor modulators [SARMs, e.g., andarine, LGD-4033 (ligandrol), enobosarm (ostarine), and RAD 140],
tibolone,
zeranol, and
zilpaterol

Doping Relevance

After the World Anti-Doping Agency (WADA) added SARMs to the Prohibited List in 2008, doping tests initially focused on the SARMs known at the time, such as Andarine and Ostarine. The first positive test results from global testing were reported in 2010, with two cases involving Andarine.
Starting in 2012, positive test results for SARMs increased steadily, with a total of 77 positive results (45 of which were for Ostarin alone) analyzed in 2018 (see Table: WADA Statistics on SARMs).

WADA Statistics: Positive Test Results for SARMs in Global Doping Controls