Last updated 18 September 2026 · SARMs Store editorial team. This guide describes published research on a compound sold by SARMs Store strictly for laboratory use. Nothing here is medical advice, a dosing instruction or a recommendation for human consumption.
Epistane (Havoc) at a glance
| Chemical name | 2a,3a-epithio-17a-methyl-5a-androstan-17b-ol |
|---|---|
| Also sold as | Havoc, Epi, Epistane, methylepitiostanol |
| Class | Methylated prohormone (17a-methyl derivative of epitiostanol) |
| Parent compound | Epitiostanol (Thiodrol), investigated in Japan in the 1960s and 1970s as an anti-oestrogen |
| Highest evidence | Case reports and in vitro receptor studies; no controlled human trial of epistane itself |
| Aromatisation | Does not aromatise to oestrogen; parent compound had anti-oestrogenic activity |
| Format | Capsule, 10mg, 90 per bottle |
| UK status 2026 | Not a licensed medicine; research use only; WADA S1 prohibited at all times |
What epistane is
Epistane is a synthetic compound built on the epitiostanol skeleton. Epitiostanol itself was developed by Shionogi in Japan and marketed under the name Thiodrol as an anti-oestrogen for breast cancer in the 1970s; it carries a 2a,3a-epithio bridge across the A ring in place of the usual 3-keto group. Epistane adds a methyl group at the 17-alpha position, the same modification found in methyltestosterone, which prevents rapid first-pass breakdown in the liver and makes the molecule orally active.
It reached the retail market in the mid 2000s under the brand names Havoc and Epistane, sold as a dietary supplement in the United States. It has never been a licensed medicine anywhere.
What the research shows
There is no controlled human trial of epistane. What exists is a small body of receptor and metabolism work plus a larger body of clinical case reports. In vitro, the compound binds the androgen receptor with moderate affinity and shows very low affinity for the oestrogen receptor, consistent with the anti-oestrogenic activity reported for epitiostanol in the 1970s Japanese trials. Its structure means it cannot be converted to oestrogen by aromatase.
The metabolism literature comes largely from anti-doping laboratories. Work published in Drug Testing and Analysis and the Journal of Steroid Biochemistry between 2010 and 2016 identified epistane's urinary metabolites, including products of the epithio bridge opening, and established detection methods for sport. Those papers confirm that the compound is absorbed and metabolised as an active androgen rather than acting as a true prohormone requiring enzymatic conversion.
The case reports are the most important part of the record. Multiple hepatology journals have described cholestatic liver injury in men who took products labelled as epistane, with jaundice, raised bilirubin and pruritus developing over weeks and resolving over months after stopping. The pattern matches the known hepatotoxicity of 17-alpha-methylated compounds as a class. Several of the reports involved products that were later found to be mislabelled, which is the reason the certificate of analysis matters more for this category than for almost any other.
How epistane differs from SARMs
SARMs such as Ostarine and RAD-140 are molecules designed to bind the androgen receptor selectively in muscle and bone while sparing the prostate and liver. Epistane is 17-alpha-methylated and acts across every androgen-receptor tissue rather than selectively. The research questions are different, the safety literature is different, and the two are treated differently by WADA (SARMs under S1.2, epistane under S1.1). Our SARMs versus peptides guide covers the third category.
Legal status in the UK, 2026
Epistane is not a licensed medicine, and selling or advertising it for human consumption would make it an unlicensed medicinal product under the Human Medicines Regulations 2012; the MHRA has taken enforcement action on that basis against retailers in this category. SARMs Store sells it strictly as a research compound. It is prohibited at all times in sport under WADA S1.1. Buyers outside the UK should read our country guides for the USA, Australia and Canada.
Testing and how to read the certificate
Because retail epistane has a documented history of mislabelling, a batch-specific certificate of analysis is the minimum a researcher should expect. It should show identity by HPLC or LC-MS against a reference standard, a purity figure, the batch number matching the bottle, and the laboratory name and date. Alpha Labs Epistane is encapsulated in the UK at 10mg per capsule with the batch number printed on every bottle. Every batch is independently tested and its certificate of analysis is published on the product page and on the Lab Testing page. Our guide on reading a certificate of analysis explains each line.
Frequently asked questions
Is epistane a SARM?
No. It is a 17-alpha-methylated compound derived from epitiostanol. The two classes have different chemistry, different research literature and different WADA listings.
Does epistane convert to oestrogen?
No. The epithio-modified A ring cannot be aromatised, and the parent compound epitiostanol was developed as an anti-oestrogen.
What has the research found about liver effects?
Published case reports describe cholestatic liver injury in men who took products labelled as epistane, consistent with the known effects of 17-alpha-methylated compounds. No controlled human safety study exists.
Is every batch tested?
Yes. Every batch is independently tested and its certificate of analysis is published on the product page and the Lab Testing page.
Key references
Shionogi and Co. Epitiostanol (Thiodrol) product monograph and the Japanese clinical reports on its anti-oestrogenic use, 1970s.
Cavalcanti G de A et al. Urinary metabolites of epistane: characterisation for doping control. Journal of Steroid Biochemistry and Molecular Biology 2013.
Case reports of cholestatic hepatitis associated with epistane-labelled products: Journal of Clinical Gastroenterology and Hepatology Communications, 2011 to 2019.
WADA Prohibited List 2026, S1.1.
Related guides
- Prohormones collection
- Trenavar research guide
- M-Sten research guide
- What the research says about PCT
- How to read a certificate of analysis
- SARMs 101 hub
Research products: Alpha Labs Epistane 10mg, 90 capsules · Alpha Labs Trenavar · Alpha Labs M-Sten · PCT and Cycle Support · Lab Testing