RAD-140 (Testolone) is not proven safe for human use. It has never been approved by the FDA, no long-term safety data exists in humans, and the only completed human trial found liver enzyme elevations in the majority of participants. Multiple case reports document severe liver injury in otherwise healthy men who used it recreationally. Here’s what the available evidence actually shows.
What RAD-140 Is and Why People Use It
RAD-140 is a selective androgen receptor modulator, or SARM. It binds to androgen receptors in muscle tissue with high selectivity, meaning it’s designed to trigger muscle growth without affecting other tissues the way testosterone does. That selectivity is why it’s marketed in fitness communities as a “safer alternative” to anabolic steroids.
The compound was originally developed for potential use in breast cancer and muscle-wasting conditions. It has never completed the clinical development process. Despite this, it’s widely sold online as a “research chemical” and used by bodybuilders and recreational lifters looking for an edge. The FDA considers it an unapproved drug, and it cannot legally be marketed as a dietary supplement in the United States.
What the Only Human Trial Found
A single phase 1 clinical trial has been completed in humans, testing RAD-140 in 22 women with metastatic breast cancer at doses of 50, 100, and 150 mg per day. The results raise real concerns even at supervised medical doses.
The most common side effects were liver-related. Elevated AST (a liver enzyme) occurred in 59% of participants, and elevated ALT (another liver enzyme) occurred in 46%. Elevated bilirubin, which signals the liver is struggling to process waste, appeared in 27% of patients. Other frequent side effects included vomiting, dehydration, decreased appetite, and weight loss, each affecting about 27% of participants.
Serious adverse events (grade 3 or higher) occurred in 73% of patients. Treatment-related serious side effects specifically hit 32% of participants. The maximum tolerated dose was determined to be 100 mg per day, meaning the 150 mg dose caused unacceptable toxicity.
This trial involved cancer patients, so some adverse events may reflect the underlying disease. But the liver toxicity pattern is consistent with what’s been seen in case reports of healthy recreational users, which is harder to dismiss.
Liver Damage in Recreational Users
Multiple published case reports document drug-induced liver injury in healthy young men taking RAD-140. These aren’t mild lab abnormalities. In one case, a man developed severe cholestatic liver injury with bilirubin levels peaking at 38.5 mg/dL, more than 30 times the upper limit of normal. His case was scored as “probable” drug-induced liver injury with a severity rating of “severe.”
Other documented cases show similarly alarming numbers. One patient’s bilirubin peaked at 20.2 mg/dL. Another, who combined RAD-140 with a second SARM, reached 34.5 mg/dL. These are levels associated with visible jaundice and significant liver dysfunction. At least six cases of SARM-associated liver injury have been formally published, with three linked directly to RAD-140.
These are only the cases that made it into medical journals. The actual number is likely higher, since many users never seek medical attention or aren’t correctly diagnosed.
Effects on Cholesterol
Preclinical data in primates shows RAD-140 significantly worsens cholesterol profiles. At the highest tested dose, HDL (“good” cholesterol) dropped by 64%, LDL fell by 53%, and triglycerides decreased by 37%. While LDL going down might sound positive, the dramatic HDL suppression is a serious cardiovascular red flag. HDL is protective against heart disease, and losing nearly two-thirds of it shifts the overall lipid balance in a dangerous direction.
The FDA’s safety warning on SARMs as a class lists increased risk of heart attack and stroke among the potential consequences. No long-term cardiovascular outcome studies have been done on RAD-140 in humans, so the actual magnitude of heart disease risk remains unknown.
Hormonal Suppression and Recovery
RAD-140 suppresses your body’s natural testosterone production. This happens because the compound activates androgen receptors, which signals the brain to stop producing the hormones that drive testosterone synthesis. The result is lower natural testosterone, potential testicular shrinkage, and in some cases, gynecomastia (breast tissue development in men).
In surveys of SARM users, 20.7% reported decreased testicle size and 22.4% reported mood swings. Acne affected about 15% of respondents. Clinical trials did not systematically track these side effects, so the true rates may differ. No controlled studies have measured how long it takes for natural testosterone levels to return to baseline after stopping RAD-140. The suppression of natural hormone production means many users feel compelled to pursue post-cycle therapy, but there’s no evidence-based protocol for this either.
What You’re Actually Buying
Even if you accept the known risks, there’s a separate problem: you may not be getting what you think. A 2017 analysis of SARM products sold online found that 59% contained ingredient amounts different from what the label stated. A full 25% contained substances not listed on the label at all. Some products contained no active SARM whatsoever, while others included unapproved drugs or contaminants.
Because RAD-140 is sold in a regulatory gray zone as a “research chemical,” there’s no manufacturing oversight, no quality control requirements, and no accountability for what’s in the bottle. The FDA has issued warning letters to companies selling these products and has pursued criminal actions against some distributors.
What’s Missing From the Safety Picture
The biggest safety concern with RAD-140 may be what nobody knows yet. No study has followed human users for more than a few months. There is no data on effects on fertility over time, no prostate safety data, no cardiovascular outcome data, and no information on what happens with repeated cycles of use. The clinical trials that do exist didn’t even track some of the most commonly reported side effects like testicular shrinkage, acne, or mood changes.
RAD-140 is sometimes framed as “safer than steroids” because of its tissue selectivity. In animal models, it does show less impact on the prostate compared to testosterone. But tissue selectivity doesn’t mean safety. The liver toxicity, cholesterol disruption, and hormonal suppression seen in humans so far are serious effects, and they occur without any of the long-term data that would normally be required before a drug reaches the public. What exists right now is a compound with one small clinical trial, a handful of alarming case reports, and millions of people using it based largely on anecdotal reports from other users.