1-Androstenedione (5α-androst-1-ene-3,17-dione), usually shortened to “1-AD,” is a synthetic steroid that was sold in the US as an over-the-counter “prohormone” supplement in the early 2000s. It was marketed as a precursor that the body converts into 1-testosterone, the steroid now sold as “DHB” (Reilly & Crouch, J Anal Toxicol 2004; Zhang & Qiu, Steroids 2006).
The single most important fact: 1-androstenedione has never been tested in a controlled human trial and was never an approved medicine. Almost everything published about it comes from anti-doping chemistry: how to make it, how to detect it, and which metabolites appear in urine. Since 2005 it has been a Schedule III controlled substance in the US, 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 androstenedione |
| Chemical name | 5α-androst-1-ene-3,17-dione |
| Formula / weight | C₁₉H₂₆O₂, 286.4 g/mol (PubChem CID 11196935) |
| 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) |
| Half-life | Not measured in humans |
| Human trials | None for 1-androstenedione itself |
| 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-Androstenedione is a 19-carbon steroid with ketone (C=O) groups at carbons 3 and 17 and a double bond between carbons 1 and 2 of the A-ring. The hydrogen at carbon 5 sits in the α position, which makes it a relative of the 5α-reduced androgens such as dihydrotestosterone (DHT) (PubChem).
It belongs to a small family of “1-ene” steroids that share this A-ring. The members differ only in whether carbons 3 and 17 carry a ketone or a hydroxyl (OH) group:
| Compound | Chemical name | Group at C3 | Group at C17 |
|---|---|---|---|
| 1-Androstenedione (1-AD) | 5α-androst-1-ene-3,17-dione | Ketone | Ketone |
| 1-Androstenediol | 5α-androst-1-ene-3β,17β-diol | Hydroxyl | Hydroxyl |
| 1-Testosterone (“DHB”) | 17β-hydroxy-5α-androst-1-en-3-one | Ketone | Hydroxyl |
| 1-Epiandrosterone (sold as “1-Androsterone”) | 3β-hydroxy-5α-androst-1-en-17-one | Hydroxyl | Ketone |
Names in this table follow the WADA list and US law (WADA 2026 Prohibited List; 21 CFR 1308.13).
The label “1-AD” was 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 marketed under that name may therefore have contained either compound. The separate 1-androstenediol entry and the 4-ene isomer, ordinary androstenedione (“4-AD”), have their own pages in the library.
Chemists have described a four-step synthesis of 1-androstenedione from stanolone acetate (a DHT ester), with 1-testosterone formed as an intermediate. The authors called the product “a prodrug of 1-testosterone” (Zhang & Qiu, Steroids 2006).
How it works in the body
Conversion to 1-testosterone
The rationale for 1-AD is that enzymes reduce its 17-ketone to a 17β-hydroxyl group, producing 1-testosterone. The evidence for this comes from animal tissue and from human urine after related compounds, not from a dosing study of 1-AD itself:
- Rat tissue. In rat liver microsomes and testicular homogenates, the diol, the dione and 1-testosterone were converted into one another (Reilly & Crouch, 2004).
- Human urine after 1-androstenediol. In excretion studies with a commercial 1-androstenediol product, oxidation to 1-androstenedione appeared to be the main metabolic route (Delbeke et al., J Steroid Biochem Mol Biol 2002).
- Human urine after 1-epiandrosterone. After a male volunteer took one capsule of a supplement sold as “1-Androsterone,” his urine contained 1-testosterone and 1-androstenedione, along with other 1-ene metabolites. One metabolite stayed detectable for up to nine days (Parr et al., Steroids 2011).
- Human urine after boldenone. 5α-Androst-1-ene-3,17-dione was one of several minor metabolites, found in low concentration, after oral boldenone (Schänzer & Donike, Biol Mass Spectrom 1992).
Taken together, these studies show that the 1-ene steroids interconvert in the body. How much 1-testosterone a given dose of 1-AD produces in a person has never been measured.
Activity of the end product
The likely active compound, 1-testosterone, has been characterized in cells and rats. It bound selectively to the androgen receptor, and in rats an equimolar dose stimulated growth of the prostate, seminal vesicles and levator ani muscle as strongly as testosterone propionate. Unlike testosterone propionate, 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. 1-AD and its relatives were promoted as giving androgenic effects without the side effects of testosterone’s 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-AD, so this remains a marketing claim rather than a measured result.
Pharmacokinetics
No study has reported the absorption, peak level, half-life or duration of action of 1-androstenedione in humans. The published analytical methods were developed to detect it, not to describe its kinetics. Reilly and Crouch, for example, developed a blood and urine assay for 1AD, its analogues and related hormones, and studied its metabolism only in rat tissue (J Anal Toxicol 2004).
Regulatory status
- Never an approved drug. No regulator has approved 1-androstenedione for any medical use.
- United States, before 2005. Steroid 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 “1-androstenedione ([5α]-androst-1-en-3,17-dione)” to the federal definition of anabolic steroids. The change took effect 90 days after enactment (Public Law 108-358); researchers date the ban on prohormones to the beginning of 2005 (Friedel et al., 2006). It is listed in Schedule III, including its salts, esters and ethers (21 CFR 1308.13).
- Sport. 1-Androstenedione 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-androstenedione
No randomized or controlled human study has tested 1-androstenedione 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 this family tested 3β-hydroxy-5α-androst-1-en-17-one (1-epiandrosterone), the compound sold as “1-Androsterone,” which the body converts in part to 1-androstenedione and 1-testosterone (Parr et al., 2011). Seventeen resistance-trained men were randomized to 330 mg/day (n = 9) or a sugar placebo (n = 8) for 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 |
| Glomerular filtration rate | −18.0% | 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-AD, but they are the best indication of what the 1-ene prohormone family does in people.
Detection in sport
Most research on 1-AD is about catching its use:
- In excretion studies of prohormone 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 and related 1-ene steroids have been published, with notes on spectral similarities that can mislead interpretation (Verheyden et al., Anal Chim Acta 2007).
- In 2020 WADA recommended isotope ratio mass spectrometry (IRMS, which tells synthetic from naturally produced steroids by their carbon isotope signature) to confirm the non-natural origin of several “pseudo-endogenous” steroids, including the 1-ene steroids such as 1AD. A validated method was published in 2022 and tested on urine collected after a single dose of a supplement containing 1AD and 1-epiandrosterone (Piper & Thevis, Drug Test Anal 2022).
Side effects and risks
There are no human safety data for 1-androstenedione. Its risks can only be inferred from related evidence, and that evidence points in one direction:
- 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, which testosterone propionate did not (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 use of 1-testosterone “has to 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
Prohormone products from this era were not reliably what the label said. A commercial 1-androstenediol preparation studied in Belgium was contaminated with several other anabolic steroids (Delbeke et al., 2002). Because “1-AD” was also used for both the diol and the dione, a product’s name did not reliably identify its contents (Reilly & Crouch, 2004). Any product sold today is outside the regulated drug supply.
Key takeaways
- A prohormone of 1-testosterone. 1-Androstenedione is the 3,17-dione 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.
- The family is active 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.
- “No estrogen” is a marketing claim. No human study has measured estradiol or side effects after 1-AD.
- 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.
- Zhang H, Qiu Z. An efficient synthesis of 5alpha-androst-1-ene-3,17-dione. Steroids. 2006;71(13-14):1088–1090. 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.
- 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.
- Schänzer W, Donike M. Metabolism of boldenone in man: gas chromatographic/mass spectrometric identification of urinary excreted metabolites and determination of excretion rates. Biol Mass Spectrom. 1992;21(1):3–16. 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.
- 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.
- 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 11196935, 1-Androstenedione. 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.