RAD-140 (Testolone): what the research says and its UK status

Searches for "what is RAD 140", "RAD 140 side effects" and "testolone UK" usually come from two kinds of reader. One has seen the compound discussed on forums and wants to know what it actually is. The other has already seen it for sale and wants to know whether the claims hold up and whether it is legal to buy in the United Kingdom. This guide is written for both. It sticks to what has been published in peer-reviewed journals, reports adverse findings alongside the rest, and does not offer any guidance on use, because RAD-140 is not a medicine, not a food supplement and is sold here for laboratory research only.

What is RAD-140?

RAD-140 is the development code for a synthetic, non-steroidal molecule first described by chemists at Radius Health in 2011 (Miller et al., 2011). The name "testolone" does not appear in the developer's publications; it is an informal name used by sellers. RAD-140 belongs to the class known as selective androgen receptor modulators, or SARMs. Like testosterone and dihydrotestosterone, it binds the androgen receptor, the nuclear receptor that controls the expression of androgen-responsive genes in muscle, bone, prostate, skin and brain.

The idea behind the SARM class is tissue selectivity: a ligand that activates the receptor strongly in skeletal muscle and bone, but weakly in the prostate and seminal vesicles. RAD-140 was described by its discoverers as potent, orally bioavailable and non-steroidal, and was characterised in several rodent models of anabolic androgen action (Miller et al., 2011). Radius Health later took it into oncology, testing it as an oral androgen-receptor-targeted agent for a subset of breast cancers (LoRusso et al., 2022). Its published human data remain limited to that phase 1 study, and RAD-140 has never been approved as a medicine anywhere in the world.

For a broader introduction to the class, see What Are SARMs? The 2026 Research Guide and SARMs Explained.

Mechanism of action

RAD-140 is an androgen receptor agonist. Once bound, the receptor moves to the nucleus and switches on androgen-responsive genes. In gonadectomised adult male rats, RAD-140 showed androgen action in peripheral tissues that largely spared the prostate (Jayaraman et al., 2014), consistent with the tissue-selective profile reported in the original preclinical work (Miller et al., 2011). Two features are worth stating clearly because they are often left out of marketing copy.

  • It is not "selective" in the sense of having no androgenic activity. In the phase 1 breast cancer trial, prostate-specific antigen rose in 16 of 20 evaluable women and sex hormone-binding globulin fell in all 18 measured, both classic markers of androgen receptor engagement throughout the body (LoRusso et al., 2022).
  • It acts on the brain as well as muscle. In cultured rat hippocampal neurons and in kainate-lesioned male rats, RAD-140 was as effective as testosterone at reducing cell death induced by apoptotic insults, an effect that depended on MAPK signalling (Jayaraman et al., 2014). This is an animal finding and says nothing about effects in people, but it shows that the compound is not confined to skeletal muscle.

The measured elimination half-life in humans, from the phase 1 study, was about 44.7 hours (LoRusso et al., 2022). Searches for "RAD 140 half life" often return a range of figures; this is the only value from a published human pharmacokinetic dataset that we can verify.

What the research reports

Preclinical studies

The 2011 discovery paper described RAD-140 as a potent, orally bioavailable androgen receptor ligand and characterised it in several rodent models of anabolic androgen action (Miller et al., 2011). The 2014 neuroprotection paper extended this to the rat brain (Jayaraman et al., 2014). No published animal study has examined long-term exposure, fertility, cardiovascular outcomes or carcinogenicity, so the preclinical dataset is narrow.

The only human trial

The single published clinical study is a first-in-human phase 1 dose-escalation trial in 22 postmenopausal women with heavily pretreated oestrogen receptor-positive, HER2-negative metastatic breast cancer (LoRusso et al., 2022). Its purpose was to find a maximum tolerated dose for cancer treatment, not to measure muscle or strength. The findings that matter for anyone reading about the compound are the adverse events:

  • Elevated aspartate aminotransferase in 59.1 per cent of participants and elevated alanine aminotransferase in 45.5 per cent, both markers of liver stress.
  • Raised total bilirubin in 27.3 per cent, and vomiting, dehydration, reduced appetite and decreased body weight reported by 27.3 per cent each.
  • Grade 3 or 4 adverse events in 16 of 22 participants (72.7 per cent), including liver enzyme elevations and low phosphate.
  • Treatment-related adverse events in 17 of 22 participants; 7 were grade 3.

The trial population was unusual, the doses were set for oncology and the participants had advanced disease, so these figures cannot be transferred to any other group. What they do show is that RAD-140 has measurable effects on liver chemistry at the exposures studied, and that no data exist for healthy adults of any age.

Case reports of harm

Since 2020 a series of case reports has linked RAD-140 to serious adverse events in people who obtained it outside any clinical setting. A 52-year-old man developed drug-induced liver injury after taking products containing RAD-140 and LGD-4033; liver biopsy showed cholestasis with granulomas, and enzymes normalised about three months after stopping (Barbara et al., 2020). Possible acute myocarditis was reported in a young man who had self-medicated with RAD-140 for bodybuilding (Padappayil et al., 2022). A 2024 systematic analysis of suspected SARM adverse events identified 20 published reports since 2020, most of them drug-induced liver injury with cholestatic or hepatocellular patterns and jaundice, and noted that the purity and actual content of the products involved were rarely known (Leciejewska et al., 2024). An Australian multicentre series of 23 liver injury cases attributed to anabolic steroids, SARMs and bodybuilding supplements found a median latency of 58 days, hospital admission in 17 of 23, a median of 175 days from presentation to normal liver tests, and one liver transplant; there were no deaths (Nash et al., 2024).

Case reports cannot establish how common these outcomes are. They do establish that the outcomes occur, and that "RAD 140 side effects" is a question with a documented answer: liver injury and cardiac inflammation are the two most serious events in the literature, alongside the hormonal suppression that follows from any androgen receptor agonist.

None of the above is a claim about any product sold on this site. The products are sold for laboratory research and have not been tested for any effect in people.

Regulatory status

United Kingdom

RAD-140 is not a licensed medicine. The Medicines and Healthcare products Regulatory Agency has never granted it a marketing authorisation. It is not an authorised food supplement or novel food, so it cannot lawfully be sold for eating. It is not a controlled drug under the Misuse of Drugs Act 1971, but supplying it for human consumption would fall under medicines law. UK sellers therefore sell it as a research chemical, to adults aged 18 or over, for laboratory use. That is the basis on which Free Muscle stocks it. See the RAD-140 collection for the brands held and the SARMs collection for the wider range.

European Union

No EU marketing authorisation exists, and the European Medicines Agency has not approved any SARM (Leciejewska et al., 2024). RAD-140 is not an authorised novel food or food supplement in the EU. National rules on research chemicals differ between member states.

United States

The US Food and Drug Administration has not approved any SARM. In 2017 the FDA issued a public warning about SARMs in bodybuilding products, citing liver toxicity and cardiovascular risk. Products marketed as dietary supplements containing SARMs are unlawful under US law. A 2017 analysis of 44 products sold online as SARMs found that only 52 per cent contained a SARM, 39 per cent contained a different unapproved drug, 25 per cent contained substances not on the label, and only 41 per cent matched the labelled amount (Van Wagoner et al., 2017).

WADA

SARMs, including RAD-140 by name, are prohibited at all times under section S1.2 (other anabolic agents) of the World Anti-Doping Agency Prohibited List. Anti-doping laboratories detect RAD-140 and its metabolites in urine by liquid chromatography-mass spectrometry (Thevis and Schänzer, 2018). We are not aware of a verified published detection window for RAD-140, so the honest statement is: detectable, window not established. Without a published window, no interval after which a test would be negative can be stated.

Common questions

Is RAD-140 a SARM or a steroid?

It is a non-steroidal SARM. Its structure contains no steroid ring system, which is one reason it was of interest to drug developers. It is still an androgen receptor agonist and shares that mechanism with anabolic steroids.

RAD-140 vs RAD-150 (TLB-150)

RAD-150 is described by sellers as an ester of RAD-140, sometimes called TLB-150 benzoate. We found no peer-reviewed pharmacology, toxicology or human data on RAD-150. Whatever is known about it is inferred from RAD-140 plus the general behaviour of esters. It is covered separately in RAD-140 vs RAD-150 (TLB-150) and the RAD-150 collection. From a regulatory standpoint the two are treated identically: unlicensed, research use only, WADA-prohibited.

RAD-140 and MK-677

The two are often searched together. They are pharmacologically unrelated: MK-677 (ibutamoren) is a growth hormone secretagogue acting on the ghrelin receptor, not the androgen receptor. We do not publish guidance on combining compounds, because both are sold for research and there are no human studies of the pair. Read MK-677: What the Research Says and the MK-677 collection for that compound on its own.

RAD-140 dosage, results and before-and-after

We do not publish dosing, cycle, stacking or outcome information for RAD-140, and we do not make claims about what it does in people. The only human data come from a cancer trial, described above. Anything else circulating online is anecdote from products of unknown content.

Does testolone work?

The published evidence shows androgen receptor engagement in animals and in a small group of cancer patients, with significant liver findings. There is no controlled trial in healthy adults measuring muscle, strength or body composition. "Work" is therefore not a question the literature can answer, and it is not a claim we make.

Tablets, capsules or liquid?

The form affects handling and measurement in a laboratory, not the molecule. Capsules and tablets contain a fixed fill per unit that a certificate of analysis can verify; liquids depend on the accuracy of the stated concentration and on stability in the solvent. Whatever the form, the question is whether the batch has been independently tested.

Is RAD-140 legal in the UK?

It is not a controlled drug, and it is sold in the UK as a research chemical to adults aged 18 and over. It is not a licensed medicine or an authorised food supplement, so it cannot lawfully be sold for human consumption, and it is prohibited in sport. See the regulatory section above for the detail.

How to verify a batch

The 2017 JAMA analysis is the strongest argument for insisting on batch-level testing: most products sold as SARMs online were mislabelled in some way (Van Wagoner et al., 2017). A certificate of analysis for the specific batch answers three questions: is the substance actually RAD-140 (identity, usually by HPLC or LC-MS against a reference standard), how pure is it (a percentage), and how much is in each unit (assay against the labelled strength). Check that:

  1. The batch number on the certificate matches the number on the packaging you receive.
  2. The certificate names an independent laboratory and carries a test date, not just a brand logo.
  3. Identity and purity are both stated. A purity figure without an identity test proves nothing.
  4. The listed strength per unit matches the assay result within a reasonable tolerance.

Every Free Muscle-brand batch is assayed by Janoshik Analytical, an independent laboratory, and the certificate for a batch is sent on request by email. For the other brands on Muscle Market, a certificate is shown only where the manufacturer supplies one for the batch held, and that is stated on each listing. A generic PDF with no batch number is not a batch certificate. Our guides to reading a certificate of analysis and Janoshik Analytical explain each field, and the lab tests page explains our testing policy.

Related reading

RAD-140 is sold for laboratory research use only. It is not a licensed medicine, has not been evaluated by the MHRA, EMA or FDA, is not a food supplement and is not for human consumption. Products are supplied to adults aged 18 and over. Nothing on this page is medical advice, and nothing on it constitutes 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. Jayaraman A, et al. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats. Endocrinology. 2014;155(4):1398-1406. PMID: 24428527.
  3. 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.
  4. Barbara M, et al. Drug-Induced Liver Injury Associated With Alpha Bolic (RAD-140) and Alpha Elite (RAD-140 and LGD-4033). ACG Case Rep J. 2020;7(6):e00409. PMID: 33062783.
  5. Padappayil RP, et al. Acute Myocarditis From the Use of Selective Androgen Receptor Modulator (SARM) RAD-140 (Testolone). Cureus. 2022;14(1):e21663. PMID: 35233331.
  6. Leciejewska N, et al. Selective androgen receptor modulator use and related adverse events including drug-induced liver injury: Analysis of suspected cases. Eur J Clin Pharmacol. 2024;80(2):185-202. PMID: 38059982.
  7. Nash E, et al. Drug-induced liver injury from selective androgen receptor modulators, anabolic-androgenic steroids and bodybuilding supplements in Australia. Aliment Pharmacol Ther. 2024;59(8):953-961. PMID: 38372012.
  8. Van Wagoner RM, et al. Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet. JAMA. 2017;318(20):2004-2010. PMID: 29183075.
  9. Thevis M, Schänzer W. Detection of SARMs in doping control analysis. Mol Cell Endocrinol. 2018;464:34-45. PMID: 28137616.