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

What Is RAD-150 (TLB-150)?

RAD-150 is a name used in the online research-chemical and bodybuilding-supplement market for a substance described as a chemically modified, longer-acting derivative of RAD-140 (testolone), an investigational selective androgen receptor modulator (SARM). It is also sold under the name TLB-150 or TLB-150 Benzoate.

Vendors describe the modification as a benzoate esterification, the same general chemical strategy historically used to slow the absorption and extend the activity of injectable testosterone products. One supplier describes the product as having a chemical structure that includes an ester chain intended to extend half-life and produce steadier receptor activation, while another describes the transformation as aiming for an extended active lifespan and steadier blood concentrations with less frequent administration. These are vendor marketing descriptions rather than findings from any controlled pharmacokinetic study.

There is a notable inconsistency in how commercial suppliers describe the compound's actual chemical identity. Several listings give RAD-150 a CAS number of 29622-29-5 with an IUPAC name describing a chloropentyl-methylamino-acetamide structure, that is, RAD-150 SARM, also known as TLB-150 or RAD-140 Ester, with the IUPAC name 2-[5-chloropentyl(methyl)amino]-N-(2,6-dimethylphenyl)acetamide and molecular formula C16H25ClN2O. This structure bears no obvious resemblance to RAD-140 or its known ester derivatives. A different supplier lists an entirely different structure for what is also called RAD-150, with a chemical formula of C27H20ClN5O, a CAS number of 1208070-53-4, and the IUPAC name (1R,2S)-1-((3-chloro-4-cyano-2-methylphenyl)amino)-1-(5-(4-cyanophenyl)-1,3,4-oxadiazol-2-yl)propan-2-yl benzoate, which is structurally consistent with a benzoate ester attached to RAD-140's actual benzonitrile-oxadiazole scaffold. This kind of disagreement between suppliers about the basic identity of a product is common in the unregulated research-chemical market and is itself a reason for caution, since a buyer cannot be certain which molecule, if either, is actually inside a given product.

RAD-150 is not the product of any pharmaceutical company development program and does not appear in the peer-reviewed literature, in FDA filings, or in clinical trial registries. Everything publicly available about it originates from commercial sellers rather than from independent laboratories or regulators.

The Parent Compound: Who Actually Developed RAD-140

RAD-140 itself was developed internally at Radius Health, Inc., which held worldwide commercialization rights to the compound and described it in SEC filings as resulting from an internal drug discovery program targeting the androgen receptor pathway in breast cancer. Radius filed an investigational new drug application for RAD-140 with the FDA in December 2016 and later initiated a first-in-human phase 1 clinical trial in postmenopausal women with hormone receptor-positive metastatic breast cancer.

RAD-140 is now known by the International Nonproprietary Name vosilasarm and carries the development code EP0062. Clinical development has since moved to Ellipses Pharma, which has advanced a reformulated version of the molecule with improved bioavailability and pharmacokinetics into an adaptive phase 1/2 dose-optimization study in patients with advanced ER+/AR+, HER2-negative breast cancer. This oncology development program has no connection to RAD-150 or to any bodybuilding or performance application, and it does not constitute evidence about the safety or effects of RAD-150 specifically.

Has RAD-150 Itself Been Studied?

No published pharmacokinetic, toxicological, or efficacy study of RAD-150 as a distinct molecule could be located in the scientific literature. The only publicly available information consists of product descriptions from research-chemical and supplement vendors, which are not peer-reviewed and are not independently verified. Even the basic claim that esterification of RAD-140 changes its half-life, potency, or side-effect profile is a vendor assertion; it has not been demonstrated in any controlled animal or human study specific to RAD-150.

Some vendors go further, stating that esterification results in increased potency and improved efficacy compared with RAD-140 itself. No data support this comparative claim. In the absence of any published pharmacokinetic study measuring blood levels, half-life, or clearance of RAD-150 in animals or humans, statements about its duration of action or comparative strength cannot be verified.

What Human Data Exist on the RAD-140 Family

The only completed human clinical trial relevant to this molecular family is a first-in-human phase 1 study of RAD-140 in postmenopausal women with ER+/HER2-negative metastatic breast cancer. The trial enrolled 22 heavily pretreated patients across dose levels of 50 mg, 100 mg, and 150 mg once daily. The most frequent treatment-emergent adverse events, occurring in more than 10% of patients, were elevated AST (59.1%), elevated ALT (45.5%), and elevated total blood bilirubin (27.3%), along with vomiting, dehydration, and decreased appetite and weight (27.3% each).

This trial was conducted in women with advanced cancer, not in healthy adults seeking muscle or strength gains, and it evaluated RAD-140 itself, not RAD-150. No comparable trial exists for RAD-150 in any population.

Separately from the formal trial, a published case report describes a young man who developed idiosyncratic drug-induced liver injury after using RAD-140 obtained as an online workout supplement, presenting with nausea, vomiting, right upper quadrant pain, and jaundice. The case report authors noted that RAD-140 is easily purchased online without a prescription and cautioned that clinicians should ask patients with unexplained liver injury about use of SARMs and similar workout supplements.

Regulatory Status

No SARM, including RAD-140 or RAD-150, is approved by the FDA for human use. The FDA has repeatedly warned that body-building products containing SARMs are unapproved drugs that the agency has not reviewed for safety or effectiveness, and that these products are not legally marketable dietary supplements. The agency states that life-threatening reactions, including liver injuries requiring hospitalization, have occurred in people taking products containing SARMs, and that SARMs also have the potential to increase the risk of heart attack or stroke, along with psychosis, hallucinations, sleep disturbances, sexual dysfunction, acute liver failure, infertility, pregnancy miscarriage, and testicular shrinkage.

The FDA has continued issuing warning letters to companies selling SARMs products, including letters sent in December 2025 to firms marketing products described as SARMs, in which the agency classified the products as unapproved new drugs under the Federal Food, Drug, and Cosmetic Act. There is no FDA-approved SARM currently available by prescription for any indication.

Doping Status

SARMs are listed as prohibited substances under section S1.2 ("Other Anabolic Agents") of the World Anti-Doping Agency's Prohibited List, which explicitly names andarine, enobosarm (ostarine), LGD-4033 (ligandrol), RAD140, S-23, and YK-11 as examples, and states this list is not exhaustive. Anabolic agents as a class are defined to include substances with a similar chemical structure or similar biological effect, including their esters.

For the 2026 Prohibited List, WADA specifically clarified this point, amending the relevant language to state explicitly that esters of prohibited anabolic agents are prohibited, using testosterone cypionate and testosterone propionate as illustrative examples of esters that change how long a drug lasts in the body. Since RAD-150 is marketed specifically as a benzoate ester of RAD-140, an explicitly named substance on the Prohibited List, it would fall under this same prohibition even though RAD-150 is not individually named. All substances in this category are prohibited at all times, both in and out of competition.

Bottom Line

RAD-150 (TLB-150) is a research-chemical market product with no independent chemical verification, no published pharmacology, and no clinical safety data specific to the molecule itself. Vendor claims about its half-life, potency, and comparative advantages over RAD-140 are unverified marketing statements. The only relevant human data come from a small phase 1 oncology trial and case reports of liver injury involving the parent compound RAD-140 in different populations and contexts than typical recreational use. RAD-150 is not approved for human use by any regulatory authority and would be treated as a prohibited substance under anti-doping rules.