5-Androstenediol (5-AD)
A DHEA-adjacent diol with the double bond in the 5-position, requiring two enzymatic steps to reach testosterone and therefore a weaker testosterone precursor than 4-androstenediol. Notable separately for radioprotective/immune research. A DASCA-scheduled controlled substance in the US.
01 Overview
5-Androstenediol (androst-5-ene-3-beta,17-beta-diol) is a direct DHEA metabolite. Because its 5-ene structure must first isomerise to the 4-ene configuration before becoming testosterone, its efficiency as an androgen precursor is lower than the 4-ene diol, and older marketing overstated its potency.
Separately, 5-AD has been studied as an immune modulator and radioprotective agent (developed as a drug candidate for radiation injury), which is its most distinct body of evidence. As a prohormone it was captured by the 2014 DASCA scheduling.
02 Mechanism
Metabolised via 3-beta-HSD/isomerase to testosterone (two-step, less efficient than 4-AD); independently acts on immune cells and has been studied for radioprotection.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Historic prohormone use | 200–400 mg/day | Oral | Old prohormone dosing; weak conversion so doses ran high. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Weak testosterone elevationLess efficient than 4-AD at raising testosterone; effect is modest. | Minor | Anecdotal | |
| Immune/radioprotective activityStudied as a radiation-injury countermeasure with effects on blood cell recovery in preclinical models. | Demonstrated in animal models | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Androgenic side effectsAcne and oily skin at higher doses. | Mild | Uncommon | Anecdotal | |
| Mild HPTA suppressionSome suppression of endogenous testosterone with use. | Mild | Uncommon | Observational |