Andarine (S-4) for Women: What the Evidence Actually Shows

Key takeaways

What andarine is and why it is marketed to women

Andarine, also known as S-4 or GTx-007, is a nonsteroidal selective androgen receptor modulator (SARM) that was originally developed using the antiandrogen bicalutamide as a chemical starting point. It was investigated as a potential treatment for muscle wasting, osteoporosis, and benign prostatic hyperplasia. Development of andarine for all of these indications was discontinued, and the company that created it, GTx, redirected its research toward a structurally related compound, enobosarm (ostarine), instead.

Because andarine and similar SARMs are marketed online as alternatives to anabolic steroids that supposedly build muscle and burn fat with less androgenic baggage, they are sometimes promoted to women seeking body recomposition. No such marketing claim has been tested in a controlled human study of any kind, in women or men, and andarine has no history of being taken into published human clinical trials.

The actual evidence base: animal studies, not human trials

The only controlled experimental work on andarine in a female biological system consists of studies in ovariectomized rats, a standard laboratory model of postmenopausal estrogen loss and bone deterioration. In one such study, researchers assigned female Sprague-Dawley rats to treatment groups following ovariectomy and measured bone mineral density, body composition, and femur strength over 120 days. The study reported that andarine treatment maintained whole body and trabecular bone mineral density and increased bone strength while decreasing body fat compared with untreated ovariectomized controls.

This finding is real, but it describes a preclinical rodent model designed to explore a possible osteoporosis therapy, not a safety or efficacy study of andarine for recreational fat loss or muscle building in women. Rat physiology, dosing, and monitoring conditions in a controlled laboratory setting do not translate directly to unsupervised human use of an unregulated research chemical. No equivalent controlled study exists in women, and andarine has never been evaluated in human trials for bone density, body composition, or any other endpoint.

Virilization risk: a mechanism-based concern without dose-response data

Andarine works by binding to and activating the androgen receptor, the same receptor that mediates the effects of testosterone. In women, sustained androgen receptor activation is the basis of virilizing effects seen with anabolic-androgenic steroids and other androgenic drugs, including voice deepening, clitoral enlargement, excess facial or body hair growth, and menstrual cycle disruption. Because andarine shares this basic mechanism, the biological plausibility of similar effects in women cannot be dismissed.

There is no published human study that has defined a dose or duration threshold below which this risk is negligible for women, because andarine has not been tested in women at all. Any statement that a particular amount is "safe" for female virilization risk is not supported by controlled evidence and should be treated as unverified.

Vision effects

A recurring feature in andarine's history is a reported yellow tinge to vision and difficulty adapting to darkness. This effect is widely cited in secondary literature and user reports as the reason the compound's development stalled, tied to androgen receptor expression in ocular tissue. However, because andarine was never carried into completed, published human clinical trials, this effect has not been formally characterized in a peer-reviewed dose-response study specific to andarine. The evidence for it rests on the compound's early development history and on accumulated anecdotal and case-level reports rather than a controlled trial, and there is no indication in the available literature that this effect differs by sex.

Liver toxicity and hormonal suppression

SARMs as a drug class, including andarine, have been associated with drug-induced liver injury. A LiverTox review compiled by the National Institute of Diabetes and Digestive and Kidney Diseases catalogs SARMs among agents linked to hepatotoxicity, and multiple published case reports describe cholestatic liver injury, jaundice, and markedly elevated liver enzymes in people who used SARM products, generally documented in male users since most published cases involve men. A 2023 systematic review of SARM safety data identified case reports of drug-induced liver injury, Achilles tendon rupture, rhabdomyolysis, and reversible liver enzyme elevation across the class, drawn from a combination of clinical trials and case reports.

Because androgen receptor activation also feeds back on the hypothalamic-pituitary-gonadal axis, androgenic compounds including SARMs are mechanistically expected to suppress the pituitary hormones luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which regulate ovulation in women and testosterone production in men. The FDA's warning about SARMs lists infertility and pregnancy miscarriage among the adverse events reported to the agency, consistent with disruption of reproductive hormone signaling, though the agency's reporting does not break these events down by sex or by which specific SARM was involved. No controlled study has measured LH, FSH, or menstrual cycle changes with andarine specifically in women.

Legal and regulatory status: FDA position and WADA prohibition

Andarine is not approved by the FDA for any use, in women or men. The FDA has issued public warnings, including a 2023 alert about SARM use among teens and young adults, stating that although these substances are often marketed as dietary supplements or sold for research use only, they are considered unapproved drugs. The agency has tied SARM use to reports of serious or life-threatening health problems, including increased risk of heart attack or stroke, psychosis and hallucinations, sleep disturbances, sexual dysfunction, liver injury and acute liver failure, infertility, pregnancy miscarriage, and testicular shrinkage, and has issued warning letters to companies selling SARM-containing products.

Andarine is also on the World Anti-Doping Agency's Prohibited List. It is named as an example SARM under section S1.2, Other Anabolic Agents, alongside ostarine (enobosarm), LGD-4033 (ligandrol), RAD140, S-23, and YK-11, and this category is prohibited at all times, both in and out of competition, for any athlete subject to the World Anti-Doping Code. There is no separate category or exception for female athletes; the prohibition applies identically regardless of sex, and under the Code's strict-liability principle an athlete is responsible for any prohibited substance found in their body regardless of intent.

No regulatory body anywhere has approved andarine as a medicine, and no over-the-counter or prescription formulation exists. Products sold online as "andarine" or "S-4" are unregulated research chemicals; independent testing of the broader SARM market has repeatedly found products mislabeled or containing substances other than, or in addition to, what is stated on the label, which the FDA and anti-doping authorities cite as an added and unpredictable layer of risk on top of the drug's own pharmacology.

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