Description
Methylstenbolone (M-Sten, Ultradrol) is a synthetic dihydrotestosterone derivative with 17α-methyl group and 2,2-dimethyl modification. The substance appeared in 2011-2012 as a prohormone supplement and was banned in the US via the Designer Anabolic Steroid Control Act 2014.
Per study reports Methylstenbolone binds to the androgen receptor and is resistant to aromatization. Pharmacology resembles Methasterone (Superdrol) - high anabolic potency, low water retention, pronounced hepatotoxicity. Animal studies show anabolic action factors of 6-12x testosterone.
Pharmacokinetically orally bioavailable with about 8-hour half-life. Bioavailability good due to 17α-methyl group.
Known effects in studies and case reports: ALT/AST elevations after 2-3 weeks, cholestasis reports, unfavorable lipid profile, HPG suppression, mild fatigue. Hepatotoxicity among the higher of the class.
In recreational research practice Methylstenbolone was popular in the designer steroid wave of the 2010s; today less widespread due to better-characterized alternatives. Cycle duration in practice 3-4 weeks.
Methylstenbolone is on the WADA banned list.
You can order Methylstenbolone as oral tablets in one bottle with 10mg per tablet.
This information is for research and educational purposes only. No medical recommendations.
Risks & Safety
Methylstenbolone is among the more hepatotoxic members of the oral anabolics and therefore sits at the top end of the risk scale. The effects documented in the literature resemble the profile of Methasterone and are pronounced.
Documented in studies and the user literature:
- Severe liver strain: as a 17α-methyl steroid, Methylstenbolone is markedly hepatotoxic. ALT/AST elevations even after 2-3 weeks and cholestasis reports are documented in case series.
- Lipid profile: an unfavorable lipid profile is described in studies.
- Suppression of natural production: HPG suppression is documented in the literature.
- Fatigue: mild fatigue under use is described in the user literature.
Baseline bloodwork before, during and after a research protocol is strongly advised. This classification does not replace medical advice. Risk and responsibility for any actual use lie entirely with the buyer.
Studies
- Cholestatic Jaundice With the Use of Methylstenbolone and Dymethazine, Designer Steroids Found in Super DMZ Rx 2.0 “Nutritional Supplement”: A Case Report - Journal of Investigative Medicine High Impact Case Reports 2014, Agbenyefia et al: case report of a 26-year-old previously healthy male who developed cholestatic jaundice after 30 days of a methylstenbolone-dymethazine stack.
- Detection of designer steroid methylstenbolone in “nutritional supplement” using gas chromatography and tandem mass spectrometry: Elucidation of its urinary metabolites - Steroids 2013: human excretion study in four volunteers identifying urinary methylstenbolone metabolites after a single oral dose.
- Studies on the in vivo metabolism of methylstenbolone and detection of novel long term metabolites for doping control analysis - Drug Testing and Analysis 2019, Piper et al: in vivo metabolism study detecting up to 40 deuterated methylstenbolone metabolites for up to 29 days post-administration.
- Designer steroids - over-the-counter supplements and their androgenic component: review of an increasing problem - Andrology 2015, Rahnema et al: review article on designer steroids including methylstenbolone with focus on hepatotoxicity, cholestasis, and endocrine side effects.




