Testolone (RAD-140)

What it is

Testolone is a selective androgen receptor modulator originally investigated for breast cancer and muscle wasting. Its clinical development was discontinued. It is marketed online as one of the strongest SARMs available, and it is among the most common undeclared ingredients found in products sold as supplements.

What’s claimed

• Steroid-level muscle gain without steroid side effects
• Neuroprotective benefits
• Suitable as a testosterone replacement

What the evidence shows

The anabolic claims rest almost entirely on animal work; human data are limited to small oncology studies and case reports (Bronze, animal basis). The neuroprotection claim comes from rodent research and has never been tested in people for this purpose. The most consequential human evidence is negative: published case reports describe severe drug-induced liver injury, including cases requiring hospital admission, in people who took it as a supplement.

The risks

• Hepatic: multiple published case reports of severe drug-induced liver injury, some requiring hospital treatment.
• Endocrine: marked suppression of natural testosterone production.
• Lipids: marked lowering of HDL ('good') cholesterol and raising of LDL, an adverse cardiovascular shift that is more pronounced with oral compounds.
• Product risk: manufactured outside any regulatory system. Independent testing repeatedly finds these products mislabelled, under- or over-concentrated, or containing entirely different active drugs, so the real exposure is unknowable from the label.
• Development history: the compound was not abandoned for commercial reasons alone; an unapproved drug has no established safe use in humans.

What needs monitoring

• Liver function tests: the single most important marker for this compound
• Lipid profile
• Testosterone and the hormonal axis, arranged by a clinician.