1-Androstenediol (5α-androst-1-ene-3β,17β-diol), sold as “1-Andro” and sometimes as “1-AD,” is a synthetic steroid that was marketed in the US as an over-the-counter “prohormone” supplement around the turn of the 2000s. The idea behind it was that the body converts it into 1-testosterone, the potent androgen now sold as “DHB” (Reilly & Crouch, J Anal Toxicol 2004; Verheyden et al., Anal Chim Acta 2007).
The most important fact: 1-androstenediol was never an approved medicine and has never been tested in a controlled human trial. What is published about it comes almost entirely from doping-control laboratories, which study how it is metabolized and how to detect it. It has been a Schedule III controlled substance in the US since the Anabolic Steroid Control Act of 2004 took effect, and it is banned in sport at all times.
This page summarizes what laboratory studies, doping-control research and regulators report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Synthetic androgen precursor (“prohormone”); 1-ene isomer of androstenediol |
| Chemical name | 5α-androst-1-ene-3β,17β-diol |
| Formula / weight | C₁₉H₃₀O₂, 290.4 g/mol (PubChem CID 11300765) |
| Approval | Never an approved drug; no medical indication or labeled dose |
| Route (as sold) | Oral supplement |
| Proposed active form | 1-Testosterone (17β-hydroxy-5α-androst-1-en-3-one) |
| Main urinary pathway in humans | Oxidation to 1-androstenedione |
| Half-life | Not measured in humans |
| US status | Schedule III anabolic steroid (named in the Anabolic Steroid Control Act of 2004) |
| WADA status | Prohibited at all times (S1.1); non-specified substance |
What it is
1-Androstenediol is a 19-carbon steroid with hydroxyl (OH) groups at carbons 3 and 17, both in the β position, and a double bond between carbons 1 and 2 of the A-ring. The hydrogen at carbon 5 is in the α position, which makes it a relative of 5α-reduced androgens such as dihydrotestosterone (DHT) rather than of testosterone itself (PubChem).
It is one of a small family of “1-ene” steroids that share this A-ring and differ only in the groups at carbons 3 and 17:
| Compound | Chemical name | Group at C3 | Group at C17 |
|---|---|---|---|
| 1-Androstenediol (1-Andro) | 5α-androst-1-ene-3β,17β-diol | Hydroxyl | Hydroxyl |
| 1-Androstenedione (1-AD) | 5α-androst-1-ene-3,17-dione | Ketone | Ketone |
| 1-Testosterone (“DHB”) | 17β-hydroxy-5α-androst-1-en-3-one | Ketone | Hydroxyl |
| 1-Epiandrosterone | 3β-hydroxy-5α-androst-1-en-17-one | Hydroxyl | Ketone |
Names follow the WADA list (WADA 2026 Prohibited List). In the 1-ene family, the 1,2 double bond replaces the 4,5 double bond of testosterone (Verheyden et al., 2007). It should not be confused with the 4-ene and 5-ene isomers (4-androstenediol and ordinary 5-androstenediol), which are different compounds listed separately in US law and on the WADA list (Public Law 108-358).
The “1-AD” naming problem
Product names in this family were used loosely. Reilly and Crouch described the supplement sold as “1AD” as containing the diol and/or the dione (J Anal Toxicol 2004). A product labeled “1-AD” could therefore have contained 1-androstenediol, 1-androstenedione, or both. The dione has its own page: 1-Androstenedione (1-AD).
Found in pig fat
In 2003, researchers reported detecting 5α-androst-1-ene-3β,17β-diol in extracts of pig fat by gas chromatography-mass spectrometry. The authors noted this was unexpected, because the compound was then sold as a “nutritional supplement” but had not previously been reported as occurring naturally in the food supply (McGregor & Erickson, J Nat Prod 2003). The finding does not mean supplement products were derived from food; they were synthetic.
How it works in the body
Conversion to other 1-ene steroids
The rationale for 1-androstenediol is that enzymes oxidize its 3β-hydroxyl group to a ketone, producing 1-testosterone. The evidence:
- Human urine. In Belgian excretion studies with a commercial 1-androstenediol product, oxidation of 1-androstenediol to 1-androstenedione appeared to be the main renal metabolic pathway (Delbeke et al., J Steroid Biochem Mol Biol 2002).
- Conversion to 1-testosterone. A doping-control group studying the 1-ene steroids stated that 1-androstene-3β,17β-diol is transformed into 1-testosterone after oral administration (Verheyden et al., 2007).
- Rat tissue. In rat liver microsomes and testicular homogenates, the diol, the dione and 1-testosterone were converted into one another (Reilly & Crouch, 2004).
- As a metabolite of related steroids. 5α-Androst-1-ene-3β,17β-diol appeared in a man’s urine after a single capsule of a supplement sold as “1-Androsterone” (1-epiandrosterone) (Parr et al., Steroids 2011). In horses given oral 1-testosterone, it was one of eight urinary metabolites (Kwok et al., Drug Test Anal 2013).
These studies show that the 1-ene steroids interconvert in the body. How much 1-testosterone a given dose of 1-androstenediol produces in a person has not been reported.
Activity of the end product
The compound expected to do the work, 1-testosterone, has been characterized in cells and rats. It bound selectively to the androgen receptor. In rats, an equimolar dose stimulated growth of the prostate, seminal vesicles and levator ani muscle as strongly as testosterone propionate, and it also increased liver weight (Friedel et al., Toxicol Lett 2006). These are animal results. The DHB page covers 1-testosterone in more depth.
About “no estrogen” claims. The 1-ene prohormones were promoted as giving testosterone-like effects without the side effects of conversion to estrogen (Reilly & Crouch, 2004 describe this as the claimed benefit). No human study has measured estradiol, body composition or side effects after 1-androstenediol, so this remains a marketing claim rather than a measured result.
Pharmacokinetics
No study has reported the absorption, peak blood level, half-life or duration of action of 1-androstenediol in humans. Reilly and Crouch developed a blood and urine assay for the 1AD compounds and related hormones, but studied metabolism only in rat tissue (J Anal Toxicol 2004). The human excretion data that exist describe which metabolites appear in urine and for how long, not blood kinetics (Delbeke et al., 2002).
Regulatory status
- Never an approved drug. No regulator has approved 1-androstenediol for any medical use.
- United States, before 2005. Testosterone and nandrolone precursors banned in sport were legally sold without a prescription as nutritional supplements (Delbeke et al., 2002).
- United States, from 2005. The Anabolic Steroid Control Act of 2004, approved October 22, 2004, added both “1-androstenediol (3β,17β-dihydroxy-5α-androst-1-ene)” and its 3α isomer to the federal definition of anabolic steroids, effective 90 days after enactment (Public Law 108-358). Both isomers are listed in Schedule III (21 CFR 1308.13). Researchers date the US ban on prohormones to the beginning of 2005 (Friedel et al., 2006).
- Sport. 1-Androstenediol (5α-androst-1-ene-3β,17β-diol) is named in class S1.1 (anabolic androgenic steroids) of the WADA list. It is prohibited in and out of competition, and all substances in class S1 are non-specified (WADA 2026 Prohibited List).
What the research shows
No trials of 1-androstenediol
No randomized or controlled human study has tested 1-androstenediol for muscle, strength, body composition or any medical outcome. Claims about its effects come from marketing and anecdote, not trials.
The closest human data: a related prohormone
The only controlled human trial in the 1-ene family tested 1-epiandrosterone (sold as “1-Androsterone”), which the body converts in part to 1-testosterone, 1-androstenedione and 1-androstenediol (Parr et al., 2011). Seventeen resistance-trained men were randomized to 330 mg/day (n = 9) or a sugar placebo (n = 8) during a 4-week training program (Granados et al., J Appl Physiol 2014):
| Outcome (change over 4 weeks) | Prohormone 330 mg/day | Placebo |
|---|---|---|
| Lean body mass | +6.3% | +0.5% |
| Back squat 1RM | +14.3% | +5.7% |
| HDL cholesterol | −38.7% | No significant change |
| LDL cholesterol | +32.8% | No significant change |
| AST (liver enzyme) | +113.8% (p = 0.05) | No significant change |
| Serum creatinine | +19.6% | No significant change |
The authors concluded that the harm outweighed any potential benefit. These results apply to a different compound and cannot be transferred directly to 1-androstenediol, but they are the best indication of what the 1-ene prohormone family does in people.
Detection in sport
Most research on 1-androstenediol is about catching its use:
- Across the Belgian excretion studies of prohormones and contaminated supplements, intake of amounts well below the recommended dose could lead to a failed doping test for up to 120 hours (Delbeke et al., 2002).
- Mass-spectrometry methods for 1-testosterone, 1-androstene-3β,17β-diol and related steroids have been published, with warnings about spectral similarities to known compounds that can mislead interpretation (Verheyden et al., 2007).
- In 2020 WADA recommended isotope ratio mass spectrometry (IRMS, which separates synthetic from naturally produced steroids by their carbon isotope signature) for several “pseudo-endogenous” steroids, including 5α-androst-1-ene-3β,17β-diol. A validated IRMS method covering it and the other 1-ene steroids was published in 2022 (Piper & Thevis, Drug Test Anal 2022).
Side effects and risks
There are no human safety data for 1-androstenediol itself. Its risks can only be inferred from related compounds:
- Lipids. In the 1-epiandrosterone trial, HDL fell by 38.7% and LDL rose by 32.8% in 4 weeks (Granados et al., 2014).
- Liver. The same trial found a 113.8% rise in AST. In rats, 1-testosterone increased liver weight (Friedel et al., 2006).
- Kidneys. Serum creatinine rose by 19.6% and glomerular filtration rate fell by 18.0% in the 1-epiandrosterone trial (Granados et al., 2014).
- Class effects. Friedel et al. concluded that 1-testosterone use must be assumed to carry the side effects typical of anabolic steroids. Across over-the-counter designer steroids, reported severe effects include liver toxicity, cholestasis (blocked bile flow, which causes jaundice), kidney failure, hypogonadism, gynecomastia and infertility (Rahnema et al., Andrology 2015).
Product quality
The commercial 1-androstenediol preparation used in the Belgian excretion studies was contaminated with several other anabolic steroids (Delbeke et al., 2002). Because “1-AD” was used for both the diol and the dione, a product’s name did not reliably identify its contents either (Reilly & Crouch, 2004). Any product sold today is outside the regulated drug supply.
Key takeaways
- A prohormone of 1-testosterone. 1-Androstenediol is the 3β,17β-diol member of the 1-ene steroid family and was sold as a precursor to 1-testosterone (“DHB”).
- No human trials. Its effects, dose-response and half-life have never been studied in people; the evidence is chemistry, rat tissue and urine metabolite work.
- Metabolized mainly to 1-androstenedione. In human excretion studies, oxidation to the dione was the main urinary pathway, and the 1-ene steroids interconvert.
- The family is active, and harmful, in humans. A related 1-ene prohormone increased lean mass and strength in a small 4-week trial but cut HDL by 38.7% and raised AST and creatinine.
- Controlled and banned. Schedule III in the US since the Anabolic Steroid Control Act of 2004 took effect, and prohibited at all times under WADA S1.1.
Sources
- Reilly CA, Crouch DJ. Analysis of the nutritional supplement 1AD, its metabolites, and related endogenous hormones in biological matrices using liquid chromatography-tandem mass spectrometry. J Anal Toxicol. 2004;28(1):1–10. PubMed.
- Verheyden K, Le Bizec B, Courtheyn D, et al. Mass spectrometric detection of and similarities between 1-androgens. Anal Chim Acta. 2007;586(1-2):57–72. PubMed.
- Delbeke FT, Van Eenoo P, Van Thuyne W, Desmet N. Prohormones and sport. J Steroid Biochem Mol Biol. 2002;83(1-5):245–251. PubMed.
- McGregor SJ, Erickson AJ. Identification of 5alpha-androst-1-ene-3beta,17beta-diol in the fat of Sus scrofa L.: a “nutritional supplement” not found previously in the food supply. J Nat Prod. 2003;66(9):1147–1148. PubMed.
- Parr MK, Opfermann G, Geyer H, et al. Seized designer supplement named “1-Androsterone”: identification as 3β-hydroxy-5α-androst-1-en-17-one and its urinary elimination. Steroids. 2011;76(6):540–547. PubMed.
- Kwok WH, Ho EN, Leung GN, et al. Metabolic studies of 1-testosterone in horses. Drug Test Anal. 2013;5(2):81–88. PubMed.
- Friedel A, Geyer H, Kamber M, et al. 17beta-hydroxy-5alpha-androst-1-en-3-one (1-testosterone) is a potent androgen with anabolic properties. Toxicol Lett. 2006;165(2):149–155. PubMed.
- Granados J, Gillum TL, Christmas KM, Kuennen MR. Prohormone supplement 3β-hydroxy-5α-androst-1-en-17-one enhances resistance training gains but impairs user health. J Appl Physiol. 2014;116(5):560–569. PubMed.
- Piper T, Thevis M. Addressing recent challenges in isotope ratio mass spectrometry: Development of a method applicable to 1-androstene-steroids, 6α-hydroxy-androstenedione, and androstatrienedione. Drug Test Anal. 2022;14(11-12):1891–1903. PubMed.
- Rahnema CD, Crosnoe LE, Kim ED. Designer steroids - over-the-counter supplements and their androgenic component: review of an increasing problem. Andrology. 2015;3(2):150–155. PubMed.
- National Center for Biotechnology Information. PubChem Compound Summary for CID 11300765, 1-Androstenediol. PubChem.
- Anabolic Steroid Control Act of 2004. Public Law 108-358, 118 Stat. 1661 (October 22, 2004). govinfo.
- Code of Federal Regulations. 21 CFR 1308.13, Schedule III. eCFR.
- World Anti-Doping Agency. The 2026 Prohibited List: International Standard. In effect January 1, 2026. WADA.