RAD-140 vs RAD-150 (TLB-150): ester chemistry and the evidence gap

Searches for "RAD 140 vs RAD 150" and "TLB 150 vs RAD 140" usually carry three questions. Is RAD-150 a different compound or a new label on an old one? Is it stronger or longer-lasting, as listings often suggest? Has anyone studied it? The short answers: it is a chemically modified form of RAD-140, the claims made for it are inferences rather than measurements, and no peer-reviewed study of it exists. This guide compares the two molecules, the one published figure that measures them side by side, and their position under UK law and anti-doping rules. It contains no guidance on use; both are sold here for laboratory research only, to adults aged 18 or over.

RAD-140 and RAD-150 at a glance

Identifiers and computed properties are from PubChem. The binding figures come from a patent, not a journal.

What is RAD-140?

RAD-140 is a synthetic, non-steroidal selective androgen receptor modulator (SARM) designed by Radius Health and characterised in a 2011 discovery paper (Miller et al., 2011). Its CAS number is 1182367-47-0. It binds the androgen receptor, the nuclear receptor that testosterone and dihydrotestosterone activate. The discovery paper described it as potent and orally bioavailable, reporting a binding constant (Ki) of 7 nM and oral bioavailability of 27 per cent in rats and 65 per cent in monkeys. Its international non-proprietary name is vosilasarm, and EP0062 is a later development code.

Its only PubMed-indexed clinical trial is a first-in-human phase 1 study in 22 postmenopausal women with oestrogen receptor-positive, HER2-negative metastatic breast cancer (LoRusso et al., 2022). It measured tolerability and tumour response, not muscle or strength. The most frequent adverse events were raised aspartate aminotransferase (59.1 per cent of participants), raised alanine aminotransferase (45.5 per cent) and raised bilirubin (27.3 per cent), and 16 of the 22 had a grade 3 or 4 adverse event. The measured elimination half-life was 44.7 hours. Case reports of liver injury and myocarditis are covered in RAD-140 (testolone): what the research says.

What is RAD-150 (TLB-150)?

RAD-150 is not a separate drug programme. PubChem's record for it (CID 68547459, titled "TLB 150 Benzoate", with RAD150 among its synonyms) is RAD-140 with benzoic acid joined as an ester to its only hydroxyl group, keeping the same (1R,2S) spatial arrangement. The systematic name is [(1R,2S)-1-(3-chloro-4-cyano-2-methylanilino)-1-[5-(4-cyanophenyl)-1,3,4-oxadiazol-2-yl]propan-2-yl] benzoate. "TLB-150", "TLB-150 benzoate" and the shorthand "TLB 150 b" all refer to this structure. None of them is an official non-proprietary name, and PubChem lists no validated CAS number for it.

The structure appears in a Radius Health patent, US 8,629,167, "Selective androgen receptor modulators". The benzoate is among the many related structures the patent lists, alongside other esters of the RAD-140 scaffold. A patent records that a molecule was made and claimed, not that it was developed further, and nothing in the public record shows the benzoate entering animal or human studies. How it came to be sold as "RAD-150" is not documented anywhere we can verify.

What the benzoate ester changes

Three differences follow directly from the structure.

• Mass. The ester weighs 497.9 against 393.8 for RAD-140, so the RAD-140 portion makes up about 79 per cent of the ester's mass. This is a calculation, not a measurement, but it means label milligrams of the two compounds are not interchangeable figures.
• Polarity. PubChem's computed XLogP3 rises from 3.1 to 5.4, and the hydrogen-bond donor count falls from two to one. On these computed values the ester is markedly more fat-soluble than its parent.
• Stability. Water can split an ester bond (hydrolysis), giving back RAD-140 and benzoic acid. Moisture, heat and time in solution therefore matter more for the ester than for the parent.

The one direct comparison: a patent binding assay

US 8,629,167 reports an androgen receptor binding assay run on a commercial kit. BindingDB has curated its results, which are deposited in PubChem as BioAssay AID 1800312 with the target mapped to the rat androgen receptor. In that assay RAD-140 had a half-maximal inhibitory concentration (IC50) of 2 nM and the benzoate ester 130 nM. On these figures the intact ester bound the receptor roughly 65 times less strongly than RAD-140.

The cautions are real: this is patent data, not peer-reviewed, from a single cell-free assay, and binding in a test tube says nothing about a living system, where an ester may be converted to its parent. What the figure does show is that the ester is not, in its own right, a more potent androgen receptor ligand. It fits the view that RAD-150 would act, if at all, as a prodrug of RAD-140. Whether, where and how fast that conversion happens has never been measured.

Is RAD-150 longer-acting or stronger than RAD-140?

Neither of the claims most often attached to RAD-150 has been tested. The idea that an ester means a longer action comes from injectable testosterone. Esterifying testosterone at the 17-beta position increases its solubility in oil, which slows its release once injected into muscle; the esters are inactive until the ester group is cleaved off, and a longer carbon side chain gives a longer duration (Shoskes et al., 2016). The slow release is a property of an oily depot in muscle, and it does not carry over automatically to an ester given by mouth.

Oral ester prodrugs usually exist for a different reason: to carry polar, poorly absorbed drugs across the gut wall. A review from Pfizer's pharmacokinetics department set out the properties of an ideal ester prodrug: weak or no activity of its own, chemical stability across a range of pH, resistance to hydrolysis during absorption, and rapid, complete breakdown to the active compound once absorbed (Beaumont et al., 2003). RAD-140 was already orally bioavailable in animals and had a 44.7-hour half-life in its human trial, so the problem a prodrug normally solves is not obviously present. Whether RAD-150 is absorbed intact, hydrolysed in the gut or liver, or releases RAD-140 slowly is unknown. "Stronger" has no basis either: the only comparative number shows weaker binding.

The evidence gap in numbers

A PubMed search on 26 September 2026 for RAD150, RAD-150, TLB150, TLB-150, "RAD140 benzoate", "RAD140 ester" and "testolone benzoate" returned no relevant records. The only hits for "RAD 150" or "TLB 150" were unrelated papers, on radiotherapy and cholesterol among others. A title and abstract search for RAD-140 under its various names returned 43 records. One compound has a small but real literature, including a human trial with adverse-event data; the other has a PubChem entry, a patent listing and one binding figure.

Everything said online about RAD-150's effects, side effects or timing is therefore extrapolated from RAD-140 or drawn from anecdote. If RAD-150 is converted to RAD-140, then RAD-140's liver enzyme findings are the relevant reference point. If it is not, nothing is known. None of this is a claim about any product sold on this site.

Regulatory status

United Kingdom: is RAD-140 or RAD-150 legal?

The two are in the same position. Neither holds a marketing authorisation from the Medicines and Healthcare products Regulatory Agency, so neither can be sold as a medicine. Neither is an authorised food ingredient, so neither can be sold as food or in a food supplement. They are supplied in the UK as research compounds for laboratory use, to adults aged 18 or over, the only basis on which Free Muscle stocks them.

European Union and United States

No SARM has gained approval from the European Medicines Agency or the US Food and Drug Administration (Leaney et al., 2021), and neither RAD-140 nor RAD-150 is approved as a medicine in either jurisdiction. Rules on import and possession differ between EU member states.

WADA and sport testing

The WADA Prohibited List bans SARMs at all times, in and out of competition, under S1.2 (other anabolic agents), and RAD140 is named there as an example. RAD-150 is not named on the WADA list, but the examples given there are not exhaustive, and the section also covers substances with a similar chemical structure or similar biological effect. As an ester of a named SARM, RAD-150 should be treated as prohibited in sport under S1.2. Under the WADA Code an athlete is responsible for any prohibited substance found in their sample, whatever the label on the product said.

No excretion study of RAD-150 exists, so its detection window is not established. RAD-140 itself is well characterised. In six excretion studies of five male volunteers each, given micro-doses far smaller than those in the cancer trial, unchanged RAD-140 stayed detectable in urine for up to 212 hours after the smallest single amount and up to 29 days after the largest, and several metabolites were tracked alongside it (Wagener et al., 2022). If RAD-150 is converted in the body, RAD-140 and its metabolites are what a laboratory would look for: detectable in principle, window not established.

Common questions

Are RAD-150, TLB-150 and "TLB 150 b" the same thing?

As names, yes: all three are used for the benzoate ester of RAD-140, and the "b" stands for benzoate. A name on a label proves nothing, though. Only the identity result on a batch certificate shows which molecule is present.

Is RAD-150 a SARM or a peptide?

It is a small synthetic molecule, classed with the SARMs because its parent is one. It contains no amino acids, so despite searches for "RAD 150 peptide" it is not a peptide.

Which one should I choose?

We do not advise on choosing a compound for any use. Listings are best compared on stated content per pack and on whether a certificate exists for the batch, as set out in our UK supplier checklist.

RAD-150 dosage, results, benefits and before-and-after

We do not publish dosing, cycle or stacking information for either compound and make no claims about outcomes. For RAD-150 there are no measured results of any kind, in people or in animals, and forum reports cannot show what a product actually contained.

How to verify a batch of either compound

Because the two molecules are so closely related, a certificate for RAD-150 has to do more than confirm that a SARM is present. Check that:

1. Identity names the right molecule. By liquid chromatography with mass spectrometry, RAD-140 gives a protonated molecule at m/z 394 (Wagener et al., 2022). Calculated from its formula, the ester's protonated molecule falls near m/z 498. A RAD-150 certificate that reports only the RAD-140 ion has identified the parent, not the product.
2. Purity accounts for the parent. A separate RAD-140 peak in a RAD-150 sample points to incomplete esterification or to hydrolysis since manufacture.
3. Content matches the label. The measured amount per capsule should match the stated strength. In the 2021 UK analysis, one product contained no active ingredient, others contained undeclared prohibited substances, and measured amounts differed from the packaging (Leaney et al., 2021).
4. Batch number and test date match the pack. For an ester that can hydrolyse, the test date also shows how old the result is.
5. Identifiers match PubChem. Check the formula and InChIKey in the table above. PubChem also holds an unrelated entry titled "Rad 150" (CID 32771, C16H25ClN2O), so a name search alone can mislead.

Every Free Muscle-brand batch, including the RAD-150 (TLB-150) Bioreactive Series and RAD-140 Testolone 10mg, is assayed by Janoshik Analytical, an independent laboratory, and the certificate for a batch is sent on request by email. For other brands, a certificate is shown only where the manufacturer supplies one for the batch held. A generic PDF without a batch number is not a batch certificate. See How to read a certificate of analysis and the lab tests page, and if a field is missing, contact us.

Related reading

• RAD-150 (TLB-150) collection: every brand stocked, with strength, pack size and certificate status.
• RAD-140 (testolone) collection.
• SARMs and the Bioreactive Series.
• RAD-140 (testolone): what the research says, including the case reports.
• What are SARMs? The 2026 research guide.

RAD-140 and RAD-150 are sold for laboratory research use only. They are not licensed medicines, have not been evaluated by the MHRA, EMA or FDA, are not food supplements and are not for human consumption. Products are supplied to adults aged 18 and over. Both are prohibited in sport under the WADA Prohibited List. Nothing on this page is medical advice or dosing, cycle or usage guidance. Summaries of published studies describe what researchers reported in their study populations and are not claims about any product.

References

1. Miller CP, et al. Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140. ACS Med Chem Lett. 2011;2(2):124-129. PMID: 24900290.
2. LoRusso P, et al. A First-in-Human Phase 1 Study of a Novel Selective Androgen Receptor Modulator (SARM), RAD140, in ER+/HER2- Metastatic Breast Cancer. Clin Breast Cancer. 2022;22(1):67-77. PMID: 34565686.
3. Shoskes JJ, et al. Pharmacology of testosterone replacement therapy preparations. Transl Androl Urol. 2016;5(6):834-843. PMID: 28078214.
4. Beaumont K, et al. Design of ester prodrugs to enhance oral absorption of poorly permeable compounds: challenges to the discovery scientist. Curr Drug Metab. 2003;4(6):461-485. PMID: 14683475.
5. Wagener F, et al. Human In Vivo Metabolism and Elimination Behavior of Micro-Dosed Selective Androgen Receptor Modulator RAD140 for Doping Control Purposes. Metabolites. 2022;12(7):666. PMID: 35888790.
6. Leaney AE, et al. Analysis of supplements available to UK consumers purporting to contain selective androgen receptor modulators. Drug Test Anal. 2021;13(1):122-127. PMID: 32748554.