RAD150 (TLB-150)

Overview

RAD150 (also written RAD-150; research code TLB-150 / TLB-150 Benzoate) is the benzoate ester of RAD-140 (testolone) — a nonsteroidal selective androgen receptor modulator (SARM) prodrug. It is NOT a peptide and NOT a steroid: it is a small-molecule ester of an oxadiazole SARM. It is also NOT an approved medicine — the ester itself has never entered any registered clinical trial.

The design idea is a prodrug: a benzoate group is attached to the 2-hydroxyl of RAD-140, and endogenous esterases are meant to cleave that group in vivo to release the active AR modulator, RAD-140. On that basis it is sold on the grey "research chemical" market as a "longer-lasting" or "more stable" RAD-140. It appears on this peptide reference because it is discussed, sold, and stacked alongside peptides in the fitness and "research chemical" community — not because it is one.

Two facts frame everything below. First, there is no peer-reviewed pharmacology or pharmacokinetic study of the ester itself — every efficacy, half-life, and dosing claim is anecdotal or extrapolated from RAD-140. Second, because it is a RAD-140 prodrug, its risk profile must be assumed to match RAD-140's, which includes documented human drug-induced liver injury and testosterone suppression.

Chemistry and structure

RAD150 is a small-molecule benzoate ester — not an amino-acid chain. Its identity is frequently mislabeled; the values below are the correct ones.

Structurally, PubChem confirms the relationship: the parent RAD-140 (CID 44200882) carries a 2-hydroxypropyl group, and TLB-150 (CID 68547459) is the benzoate ester of that same scaffold. This is a naming-collision hazard: the identifier "TLB-150" is also attached to an unrelated lidocaine-type acetamide (PubChem CID 32771), and some reagent catalogs describe "TLB-150 benzoate" as a "nerve conduction blocker." Those are database/naming artifacts — the correct entity here is CID 68547459, and they must not be read as the pharmacology of this compound.

Mechanism of action

• Prodrug design (ester hydrolysis to active parent). [Hypothesis] RAD150/TLB-150 is the benzoate ester formed on the 2-hydroxyl of RAD-140. The intent is that esterases cleave the benzoate group in vivo to release active RAD-140, slowing appearance and clearance versus the free parent. This is confirmed structurally by PubChem, and the ester-to-active-parent mechanism is chemically plausible — but it has NOT been demonstrated in any published PK/ADME study for this specific ester.
• Active moiety RAD-140 is a nonsteroidal SARM. [Animal] The released parent, RAD-140, is a potent, orally bioavailable high-affinity AR agonist with reduced activity in prostate and other androgenic tissues (a tissue-selective anabolic:androgenic profile). Reported in Miller et al., ACS Med Chem Lett 2011 (PMID 24900290) in rodent/primate preclinical models.
• Oncology rationale of the parent (AR in breast tissue). [Human] In AR+/ER+ breast cancer, RAD-140's AR agonism can suppress tumor-cell growth — the rationale for its development as vosilasarm/EP0062. A Phase 1 dose-escalation study in ER+/HER2- breast cancer (NCT03088527; Annals of Oncology 2019, abstract 343P) reported target engagement and preliminary antitumor activity, provisional MTD 100 mg QD. This is evidence for the parent drug, not the RAD150 ester.
• No ester-specific data. [Hypothesis] No independent mechanism, receptor-binding, selectivity, or pharmacokinetic data exist for the TLB-150 ester as a distinct chemical entity. Its own absorption, hydrolysis rate, active-drug exposure, and half-life are unmeasured in the peer-reviewed literature. Every mechanistic statement about RAD150 is extrapolated from RAD-140.

Research and evidence

The honest position: there is no research on RAD150 itself. The table below separates what is known about the ester (nothing) from what is known about the parent RAD-140.

Human evidence in context. There are no completed human trials of RAD150 — none at all. The only controlled human data anywhere in this family come from the RAD-140 oncology program (a Phase 1 study in breast-cancer patients), and those used the parent compound, not the ester. Human efficacy of RAD150 for physique, performance, or anything else is not established. The grey-market "evidence" for RAD150 is anecdote, plus adverse-event experience inherited from RAD-140.

Status and regulation

• Regulatory approval: None. RAD150/TLB-150 is not approved by the FDA, the EMA, or any other regulator for any indication, and the ester has never entered a registered clinical trial. The active parent RAD-140 (vosilasarm/EP0062) is investigational in oncology; RAD150 itself is a research-chemical-market compound with no legitimate pharmaceutical developer.
• Anti-doping: Prohibited by the World Anti-Doping Agency (WADA) at all times (in- and out-of-competition) under S1.2 (Other Anabolic Agents) — as a RAD140 prodrug. RAD140 is explicitly named on the WADA Prohibited List. WADA is a sport-eligibility axis and is separate from any question of legality.
• Market reality: Outside any trial, it is sold only as an unregulated "research chemical," frequently marketed as a "longer-lasting" RAD-140 and — critically — often mislabeled (see Safety).

Safety

Documented and expected safety signals (tagged by evidence type):

• Hepatotoxicity / DILI [Human]. As a RAD-140 prodrug, assume comparable risk. Published human case reports document cholestatic liver injury from RAD-140, including markedly elevated bilirubin and jaundice; the class-level hepatotoxicity is reviewed in LiverTox (NBK619971).
• HPTA / endogenous testosterone suppression [Human — class effect]. AR agonism suppresses the hypothalamic-pituitary-gonadal axis; suppression is an expected class effect of AR-active SARMs including RAD-140. Quantitative suppression data specific to the RAD150 ester are not established.
• FDA safety warning [Human]. The FDA warns that SARMs are associated with serious, life-threatening harms including liver injury and acute liver failure, heart attack, and stroke, and states SARMs cannot be legally marketed as dietary supplements or drugs.
• Unknown ester-specific toxicity and pharmacokinetics [Hypothesis]. No PK/ADME study of the ester exists, so real active-RAD-140 exposure, accumulation, and duration are unquantified; vendor half-life figures are unverified.
• Naming-collision hazard [In vitro]. "TLB-150" is also attached to an unrelated lidocaine-type acetamide (PubChem CID 32771), and some catalogs call "TLB-150 benzoate" a "nerve conduction blocker." These are database artifacts — do not read them as this compound's pharmacology. The correct entity is CID 68547459.

Legal status

How it compares

RAD150 is best understood as "RAD-140 with an ester bolted on and no data of its own."

• Testolone (RAD-140) — the active parent. Everything RAD150 is claimed to do depends on releasing RAD-140. RAD-140 at least reached Phase 1 in oncology and carries the strongest liver-injury signal among common SARMs; RAD150 is the untrialed ester of it, inheriting those risks with none of the human data.
• Ostarine, Ligandrol, Andarine — other nonsteroidal SARMs sharing the AR-agonism mechanism, suppression risk, WADA S1.2 status, and lack of approval.
• Stenabolic (SR9009) and Cardarine (GW-501516) are frequently sold alongside SARMs but are NOT SARMs — a Rev-Erbα agonist and a PPARδ agonist respectively.

The decisive point: RAD150 is a prodrug with zero trials of its own, not approved for anything, and its most-documented risks are inherited from RAD-140 — liver injury and testosterone suppression — not a benchmarked, evidence-backed physique or performance therapy. See the Muscle, growth & hormones overview.

Common misconceptions

• "RAD150 is a peptide." No. It is a synthetic small-molecule benzoate ester (C27H20ClN5O3, 497.9 g/mol) of a nonsteroidal SARM. It is covered here only because it is discussed and stacked with peptides.
• "RAD150 is 'testolone enanthate.'" No — this is the single most common labeling error. RAD150/TLB-150 is a benzoate ester (PubChem CID 68547459), not an enanthate. A product sold as an "enanthate" is mislabeled at best.
• "It's a proven, longer-lasting RAD-140." The "longer-lasting" claim rests on no measured pharmacokinetics — vendor "~48-60 h" half-life figures are unverified marketing. The ester has never been studied in any trial.
• "It's a milder, safer, legal alternative to steroids." No. Assume RAD-140's risks: drug-induced liver injury and testosterone suppression. "SARM" does not mean "safe," and a prodrug with no data of its own is not safer than its parent.
• "Buying it as a 'research chemical' means it's clean and correctly dosed." No. Independent testing (JAMA 2017) found most products sold as SARMs were mislabeled, contained a different drug, or contained nothing — and RAD150 is additionally mislabeled as an "enanthate."

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This entry is educational and summarizes published research and public regulatory information as of the "updated" date above. It is not medical advice, not legal advice, a recommendation, or a guide to obtaining or using any substance.