RAD-140 — also called Testolone — is one of the most widely researched selective androgen receptor modulators (SARMs) in the world. In this guide, I break down everything currently known from preclinical research: what it is, how it works, what the data shows, and where US and UK researchers source it. This is for research purposes only.
RAD-140 is a non-steroidal selective androgen receptor modulator developed by Radius Health Inc. first described in a 2011 patent. It was originally investigated as a potential treatment for muscle wasting conditions and hormone-sensitive breast cancer.
Unlike anabolic steroids, SARMs like RAD-140 are designed to selectively target androgen receptors in muscle and bone tissue, theoretically reducing androgenic effects on other organs. However, it is important to note that RAD-140 remains an unapproved research chemical — it has never completed Phase III clinical trials and is not approved for human use by the FDA (USA) or MHRA (UK).
⚠ Research Purposes Disclaimer: All information on this page is for educational and research purposes only. RAD-140 is not approved for human consumption. Do not use this compound without consulting a licensed medical professional.
RAD-140 binds selectively to androgen receptors. In animal research, it demonstrated a high anabolic-to-androgenic ratio — approximately 90:1 compared to testosterone's 1:1 ratio. This means in research models it showed strong anabolic activity with reduced androgenic activity.
The mechanism involves:
Source: Jayaraman A, et al. "Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats." Endocrinology. 2014. PubMed
Preclinical data on RAD-140 is promising but limited. The majority of studies have been conducted in vitro (cell studies) or in animal models. There is limited human clinical trial data available.
| Study Type | Finding | Source |
|---|---|---|
| Animal (primate) | Increased lean mass, reduced fat mass over 28 days | Miller et al., 2011 |
| Animal (rat) | Neuroprotective effects, reduced neuronal death | Jayaraman et al., 2014 |
| In vitro | Inhibits androgen-sensitive breast cancer cell growth | Yu et al., 2017 |
| Phase I trial | Ongoing — no published results as of 2026 | ClinicalTrials.gov |
It's critical to understand that animal research does not directly translate to human outcomes. RAD-140 remains an investigational compound.
The following information is derived from preclinical research and anecdotal researcher reports. This is not medical advice and is presented for research documentation purposes only.
| Parameter | Research Data | Notes |
|---|---|---|
| Animal study dose | 0.1–1 mg/kg bodyweight | Primate studies, not human |
| Half-life (estimated) | ~60 hours | Based on pharmacokinetic modelling |
| Research cycle length | 4–12 weeks in studies | Animal models only |
| Form studied | Oral (liquid and capsule) | Sublingual absorption also studied |
Based on available preclinical data and Phase I trial monitoring, the following adverse effects have been flagged as areas for research attention:
Any researcher working with RAD-140 should maintain thorough bloodwork records including LH, FSH, testosterone, liver enzymes (ALT/AST) and lipid panels.
Animal studies indicate RAD-140 suppresses the hypothalamic-pituitary-gonadal (HPG) axis to varying degrees. Research protocols involving RAD-140 often include post-cycle recovery phases to monitor hormonal restoration.
Common research compounds studied alongside RAD-140 recovery include Clomiphene (Clomid) and Enclomiphene, though these are also unapproved for this specific use.
United States: RAD-140 is not a scheduled controlled substance under the DEA Controlled Substances Act. It can be legally purchased as a research chemical. However, it is explicitly not approved by the FDA for human consumption, and selling it as a dietary supplement is illegal.
United Kingdom: RAD-140 is not listed under the Misuse of Drugs Act 1971. It is legal to purchase as a research chemical. It is not licensed as a medicine by the MHRA. The Medicines Act 1968 may apply if sold with medicinal claims.
Always check current legislation in your jurisdiction. Laws around research chemicals change and this information may not reflect the most current legal position. This is not legal advice.
For researchers in the USA and UK, third-party tested sources are essential. The following vendors provide certificates of analysis (CoA) from independent labs:
⚠ Affiliate disclosure: links above may earn Tom's Fitness Blog a commission at no cost to you. We only list vendors with verified third-party testing.
⚠ Full Research Disclaimer: This article is for informational and educational research purposes only. RAD-140 (Testolone) is an unapproved research chemical. It is not approved for human consumption by the FDA (USA) or MHRA (UK). Nothing on this page constitutes medical advice. The author and Tom's Fitness Blog accept no liability for use of information presented here. Always consult a licensed medical professional. Some links are affiliate links — see our affiliate disclosure.