Supplements for Athletic Performance

An early nonsteroidal SARM (S-4 / GTx-007) that was studied preclinically for muscle and bone but NEVER advanced to approval. There are NO human efficacy trials — the anabolic results are from castrated and ovariectomized rats (Gao 2005, Kearbey 2007). It is best known for a distinctive, reversible visual side effect (yellow-tinted vision and impaired night/dark adaptation), it suppresses the body's own testosterone axis, it is banned by the World Anti-Doping Agency, and it is sold only as an unregulated grey-market research chemical that may have unreliable identity, strength or quality. The honest summary is preclinical-only with real trade-offs.

A selective androgen receptor modulator (SARM) sold grey-market for muscle and body composition. Its anabolic and anti-cancer data are preclinical (cells/animals); the only human studies are a Phase-1 breast-cancer safety trial and case reports of severe liver injury. WADA-banned, suppresses natural testosterone, and grey-market products may have unreliable identity, strength or quality.

An abandoned PPARδ agonist 'exercise mimetic' — development was halted when long-term animal studies found tumors across multiple organs. The headline endurance result is from mice on a treadmill (Narkar 2008). Small human trials have studied GW501516 and reported changes in lipid biomarkers. These findings do not establish improved exercise performance, longevity benefits or long-term safety. Animal cancer findings remain a serious concern. SupStack does not recommend self-directed cardarine use. It is banned by the World Anti-Doping Agency as a gene-doping agent and is sold as an unregulated grey-market research chemical. The cancer signal — not the endurance hype — is the real story.

A high-potency oral SARM with ZERO human efficacy data — its only published animal work was as a reversible male contraceptive in rats, where it built muscle and bone while shutting down the HPTA and suppressing sperm to infertility. Sold grey-market for body composition, products may have unreliable identity, strength or quality, and it is banned by WADA. The human literature is limited to anti-doping detection, not benefit. It is described here to inform, not to recommend.

A grey-market AMPK activator marketed as an 'exercise mimetic' on the strength of a single famous mouse study — Narkar 2008, where 4 weeks of AICAR boosted treadmill running endurance 44% in sedentary mice. That endurance signal has NEVER been shown in humans. The only human trials of AICAR (as the drug acadesine) were for a completely different purpose — protecting the heart during cardiac-bypass surgery — and the large, definitive RED-CABG randomized trial was NEGATIVE. AICAR has poor oral bioavailability (it's injected in studies), is WADA-banned as a doping agent, and is not an approved drug or a regulated supplement. There is no human exercise-performance evidence.

A very new preclinical 'exercise mimetic' research chemical with NO human data of any kind — every result below is from mice or cultured cells. SLU-PP-332 is a synthetic agonist of the estrogen-related receptors (ERRα/β/γ), orphan nuclear receptors that drive the mitochondrial/oxidative gene program normally switched on by aerobic exercise. In mice it boosted running endurance and fat oxidation, alleviated diet-induced obesity, and improved heart-failure outcomes — a genuinely interesting mechanism. But it has never been tested in a single human, it isn't an approved drug or a lawful supplement, the original compound isn't even orally bioavailable (mouse studies inject it), and its long-term safety is completely unknown. It is described here to inform, not to recommend.

A grey-market research chemical marketed as 'exercise in a bottle' — every result is from mice or cells, with NO human trials of any kind. SR9009 ('Stenabolic') is a synthetic agonist of REV-ERB, a circadian-clock nuclear receptor, and in mice it shifted metabolic gene expression, raised energy expenditure, reduced fat mass, and increased running capacity. But it has never been tested in a single human, it is essentially inactive when taken orally (poor bioavailability), and a 2019 PNAS study showed several of its effects persist in mice lacking REV-ERB entirely — meaning they are off-target, not the advertised mechanism. It is not an approved drug or a regulated supplement, it is banned by the World Anti-Doping Agency, and it is sold online with no quality control. It is described here to inform, not to recommend.