Testolone (RAD-140)

Testolone, also known by the development codes RAD140 or RAD-140, and the generic name Vosilasarm, is a non-steroidal Selective Androgen Receptor Modulator (SARM).

SARMs are a class of compounds designed to act as agonists (activators) on androgen receptors (AR) in a tissue-selective manner, aiming to produce beneficial anabolic effects in tissues like muscle and bone with fewer side effects in other tissues like the prostate, compared to traditional anabolic steroids.

It is currently an investigational drug, primarily under development for the treatment of hormone-sensitive breast cancer. Development for other indications like sarcopenia (muscle wasting) has been discontinued. It is often illegally sold and used in the black market for physique and performance enhancement.

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Benefits (Investigational & Anecdotal)

The potential benefits of RAD-140 are largely extrapolated from preclinical studies and anecdotal user reports, as it is not approved for human use outside of clinical trials:

• Muscle Growth (Anabolic Effect): Preclinical studies and user reports suggest a potent anabolic effect, promoting increases in lean body mass.

• Bone Health: Like other SARMs, it is theorized to increase bone density and strength.

• Neuroprotection: Preclinical data suggests it may protect brain neurons against cell death caused by certain insults, indicating potential therapeutic use in neurodegenerative diseases.

• Tissue Selectivity (Proposed): The intended benefit of SARMs is to have a high anabolic-to-androgenic ratio, producing muscle-building effects while sparing the prostate and other androgen-sensitive tissues from unwanted side effects. In clinical trials for breast cancer, it has shown anti-androgenic effects in the breast and prostate.

Side Effects (Reported & Potential)

Since RAD-140 is an unapproved, experimental drug, its full safety profile is not well understood. Reported and potential side effects include:

• Liver Toxicity (Hepatotoxicity): Case reports have documented drug-induced liver injury (DILI), including severe cholestatic hepatitis and acute liver failure, following RAD-140 use.

• Cardiovascular Risks: There are reports of serious cardiac events, such as myopericarditis (inflammation of the heart muscle and surrounding tissue), even after a single dose.

• Hormonal Changes: As an AR agonist, RAD-140 can suppress natural testosterone production, potentially leading to symptoms of low testosterone (e.g., fatigue, changes in libido) upon cessation.

• Gastrointestinal Distress: Vomiting, decreased appetite, and constipation have been reported in clinical trials for breast cancer.

• Other: Changes in sex hormone levels and elevated liver enzymes have been observed.

Pros and Cons Summary

 

Dosage and Frequency

Note: There is no standardized medical dosage for performance enhancement, as this is an unapproved and illegal use. Dosages mentioned in non-medical contexts are highly variable, unsupported by clinical data for this purpose, and carry significant risk.

• Investigational Doses (Breast Cancer Trials): Clinical trials in women with breast cancer have assessed doses ranging from 50 mg to 150 mg per day, with 100 mg/day being the maximum safe and tolerated dose in one study.

• Black Market/Anecdotal Dosing: Non-medical users commonly report doses ranging from 10 mg to 30 mg once daily. The once-daily frequency is supported by its long half-life.

Pharmacokinetic Data

• Half-Life: The elimination half-life is reported to be between 45 to 60 hours. This long half-life supports a once-daily dosing regimen.

• Detection Time (Doping Control): RAD-140 is a prohibited substance by the World Anti-Doping Agency (WADA). The parent compound has been detected in urine up to 8 days after a single 10 mg dose. It is generally assumed that it could be detectable for up to 10 to 14 days or possibly longer depending on the dose, frequency, and detection method.

Sterogenic, Progestronic, and Prolactin Affects

• Sterogenic/Estrogenic Effects: RAD-140 is a non-steroidal SARM and does not interact with the aromatase enzyme that converts testosterone to estrogen. Therefore, it is not expected to cause estrogenic side effects like gynecomastia through this pathway.

• Progestronic Effects: Preclinical data suggests RAD-140 has low affinity for the progesterone receptor (PR). One study reported an IC50​ of 750 nM for the PR, which is significantly lower than for the Androgen Receptor (Ki​=7 nM). This indicates it is unlikely to exhibit significant progestogenic effects.

• Prolactin Effects: There is no significant evidence to suggest that RAD-140 directly increases prolactin levels. SARMs are not typically associated with the direct prolactin increases seen with some progestins or specific anabolic steroids.

Anabolic Androgenic Ratio

The anabolic-to-androgenic (A:A) ratio is a measure of a compound's ability to promote muscle growth (anabolic) versus its ability to cause androgenic side effects (like prostate enlargement or virilization).

• Anabolic Androgenic Ratio: RAD-140 is often cited as having an A:A ratio of approximately 90:1 (Anabolic:Androgenic), which is considered very favorable compared to testosterone's ratio of 100:100 (1:1). This is based on preclinical data showing strong anabolic activity in muscle tissue and a less potent, or even antagonistic, effect in the prostate.