RAD-150 (TLB-150): What the Evidence Actually Shows

Key takeaways

What is RAD-150?

RAD-150, also sold as TLB-150 or TLB-150 Benzoate, is marketed by online vendors as a chemically modified version of RAD-140 (Testolone), produced by attaching a benzoate ester group to the RAD-140 molecule. Vendor listings describe this as a prodrug strategy, in which the ester is intended to be cleaved in the body to release RAD-140 as the active compound.

The stated rationale offered by commercial sellers for this modification is pharmacokinetic: esterification is claimed to extend how long the compound stays active and to smooth out blood concentrations, which would in principle allow less frequent dosing in an experimental setting. This is a plausible mechanism in general medicinal chemistry terms, but no independent source confirms it applies to RAD-150 specifically.

It is important to be precise about what RAD-150 actually is. Unlike RAD-140, which has at least reached an early-phase human oncology trial, RAD-150/TLB-150 does not have a published pharmacology, toxicology, or clinical trial record in the peer-reviewed literature, and no registered study of it was identified on ClinicalTrials.gov. Every specific claim about its effects, half-life, selectivity, or safety currently circulating online traces back to manufacturer and retailer marketing copy rather than to independent scientific data. This means that essentially all specific numeric or mechanistic claims made about RAD-150 are unverified extrapolations from its parent compound, not findings generated from RAD-150 itself.

How RAD-150 is supposed to work, and why the evidence is thin

Selective androgen receptor modulators (SARMs) are a class of non-steroidal compounds designed to bind the androgen receptor and activate anabolic signaling in muscle and bone while, according to their developers, producing less stimulation of androgenic tissue compared with testosterone or anabolic steroids. This general framework underlies the design of RAD-140 and other SARMs that have entered early clinical testing.

For RAD-150 specifically, the mechanistic story told by sellers is that it functions as a prodrug: an ester bond is hydrolyzed in the body to release RAD-140, which is then responsible for receptor binding and any downstream effects. This is the standard commercial framing found on retailer product pages, but it has not been confirmed in any controlled study.

No independent, peer-reviewed pharmacokinetic study has confirmed the rate, extent, or clinical relevance of this hydrolysis in humans or animals. Claims about a specific extended half-life, a particular fold-increase in potency, or superior tissue selectivity for RAD-150 are not supported by any citation to a controlled study; they appear only in commercial and enthusiast content. The strength of evidence for RAD-150's mechanism of action is therefore very low: it rests entirely on inference from a structurally related but distinct compound, not on direct evidence.

What is actually known about the parent compound, RAD-140

Because RAD-150 has no independent human data, essentially everything that can be said about this drug family relies on research conducted on RAD-140. A first-in-human, phase 1 dose-escalation study evaluated oral RAD140 for safety, tolerability, maximum tolerated dose, pharmacokinetics, and antitumor activity in postmenopausal women with ER+/HER2-negative metastatic breast cancer, not in healthy people seeking muscle gain. Twenty-two heavily pretreated patients were enrolled across 50 mg, 100 mg, and 150 mg once-daily dose levels.

That same oncology trial is notable for what it found regarding liver safety signals. The most frequent treatment-emergent adverse events, occurring in more than 10% of patients, were elevated AST (in 59.1% of patients), elevated ALT (in 45.5%), and elevated total blood bilirubin (in 27.3%), alongside vomiting, dehydration, and decreased appetite and weight. In other words, even in a formal clinical trial with medical supervision and a relatively short treatment course, liver enzyme abnormalities were common enough to be a leading adverse event category. The trial investigators nonetheless concluded that RAD140 had an acceptable safety profile with preliminary evidence of target engagement and antitumor activity in this specific, closely monitored cancer population, which is a different question from whether the compound is safe for unsupervised use by healthy adults.

Outside this oncology setting, RAD-140 has not been evaluated in controlled trials of healthy adults for muscle-building purposes. What exists instead is a growing body of case reports describing adverse events in people who obtained RAD-140 online and used it without medical supervision, discussed in detail below. These reports come from real clinical encounters, but as individual case reports they cannot establish how common any given harm is among all users.

Reported side effects and safety concerns

The most consistent, well-documented harm associated with RAD-140 use is liver injury. Multiple independent case reports describe this pattern. One report presents a 29-year-old male who developed liver injury after taking RAD-140, with jaundice and elevated liver enzymes appearing after three months of use, and hepatic steatosis with a hyperechoic lesion on ultrasound; his symptoms resolved after he stopped the drug. A separate case describes a 24-year-old male who presented with abdominal pain, scleral icterus, pruritus, and jaundice after taking RAD-140 for muscle growth for five weeks, with a cholestatic pattern of liver injury and a peak total bilirubin of 38.5 mg/dL; a liver biopsy supported a diagnosis of RAD-140-associated liver injury, and his symptoms and liver injury resolved after he stopped taking it. A third case involved a 22-year-old, previously healthy male who presented with worsening jaundice, nausea, fatigue, pruritus, dark urine, and light stools after reportedly taking RAD-140 for 16 weeks, with markedly elevated bilirubin and bile sludge seen on ultrasound.

A case reported in Australian Prescriber underscores how severe this can become. The authors note that because of the variable potency and toxic effects of these supplements, development of acute liver failure requiring liver transplant is a possibility, and they identify RAD-140 (also called testolone or radarine) as the SARM involved; in their patient, liver biochemistry continued to worsen for six weeks even after the drug was stopped, and the authors state that had he continued using it, his liver failure might have progressed to the point of needing a transplant. A broader review of SARMs in the LiverTox database notes that some patients with prolonged jaundice and disabling symptoms have been referred for liver transplantation evaluation, but that almost all eventually improved spontaneously and transplantation was avoided in reported cases. This is a genuinely reassuring pattern in the cases published so far, but it should not be read as a guarantee: the reported denominator of cases remains small, and an Australian case series notes that fewer than 20 published cases of SARM-associated liver injury (across RAD-140, ligandrol, ostarine, and YK-11) had been reported in the literature since 2020, which limits how confidently outcomes can be generalized.

Liver injury is not the only serious harm reported with RAD-140. A case report describes a young male who presented with shortness of breath and was given a presumptive diagnosis of RAD-140-induced acute myocarditis after self-medicating with the drug for bodybuilding. Separately, a report in JACC: Case Reports describes a 16-year-old boy who developed myopericarditis, with chest pain beginning within hours of his first and only dose of RAD-140; the authors note that in addition to this cardiac presentation, several other patients have been reported with liver injury after RAD-140 use, and that the class's life-threatening side effects are not well characterized. A broader systematic review of SARM safety data in healthy adults, covering 33 studies and case reports, identified 15 case reports of drug-induced liver injury across the SARM class, along with individual reports of Achilles tendon rupture and rhabdomyolysis, indicating that liver injury is the most frequently reported harm but not the only one.

Regulatory bodies describe an even wider harm profile for the SARM class as a whole. The FDA states that SARMs are associated with 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.

An additional, practical risk applies specifically to products sold as RAD-150: because it is an unregulated product rather than a pharmaceutical-grade one, there is no assurance of purity, correct labeling, or accurate dosing. In an Australian case series of patients with drug-induced liver injury linked to SARMs, testing of the actual products used confirmed the presence of the labeled SARM in some cases, but in at least one product an additional, undeclared SARM was also identified, illustrating that what is sold does not always match what is labeled. No independent laboratory analyses specific to RAD-150 products were identified in the literature search for this article, so people considering RAD-150 have no published quality-control data confirming that commercial products match their labels.

Legal status: FDA, WADA, and other regulatory bodies

No SARM, including RAD-140 or RAD-150, is approved by the FDA for any human use. In an April 2023 consumer update aimed at teens and young adults, the FDA stated that it continues to receive adverse event reports related to SARMs, and that although SARMs are often marketed as dietary supplements or sold for research use only, they are considered unapproved drugs that cannot legally be marketed in the United States as a dietary supplement or drug. The agency has issued warning letters to companies selling these products and has pursued criminal actions against distributors, and it advises consumers not to use SARM products and to consult a healthcare professional about safer alternatives for building muscle or improving athletic performance.

Products labeled 'for research use only,' including those marketed as RAD-150, are not exempt from this concern; the FDA's stated position treats SARMs sold to consumers, regardless of labeling, as unapproved drugs rather than legitimate research reagents or dietary supplements.

In competitive sport, RAD-140 is explicitly named on the World Anti-Doping Agency's Prohibited List, where selective androgen receptor modulators, including RAD140, are listed under section S1.2, 'Other Anabolic Agents,' a category that is prohibited at all times, both in and out of competition. Because RAD-150 is chemically an ester designed to convert to RAD-140 in the body, it would be reasonable for anti-doping authorities to treat products marketed as RAD-150 with the same scrutiny as RAD-140 itself, though this article did not find a WADA ruling or guidance document naming RAD-150/TLB-150 specifically.

Australia's Therapeutic Goods Administration has taken a parallel position. A case report published through Australian Prescriber notes plainly that SARMs are not approved by the TGA, yet are readily accessible online as body-building or nutritional supplements. No major national medicines regulator has approved RAD-140 or any RAD-140 derivative, including RAD-150, for any indication.

RAD-150 vs RAD-140: is the ester actually different?

Retailers marketing RAD-150 frame it as an improvement on RAD-140, promising a longer active window, steadier blood levels, and less frequent dosing. These are the kinds of claims that would ordinarily need to be confirmed with comparative pharmacokinetic data, ideally from controlled animal or human studies measuring blood concentrations of RAD-150 and its hydrolysis product over time. No published, peer-reviewed comparative study of this kind was located for RAD-150.

Esterification is a long-established medicinal chemistry technique used in approved pharmaceuticals, including some testosterone esters, to alter absorption and duration of action, so the underlying chemical logic behind an ester prodrug is not inherently implausible. The problem is evidentiary, not conceptual: plausibility is not the same as proof, and no data specific to RAD-150 exist to confirm that it behaves as marketed, that it converts efficiently and safely to RAD-140 in humans, or that it carries a materially different risk profile than RAD-140 itself. Given that RAD-140 already carries a documented signal for liver injury and, in isolated reports, cardiac inflammation, there is no evidentiary basis to assume that an ester version would be safer; if anything, an unconfirmed additional metabolic step (ester hydrolysis) introduces further pharmacological uncertainty rather than less.

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