C tier · mixed
A pharmacologically well-characterised endogenous androgen with a genuine marketing authorisation in a few European countries and two informative randomised trials, but the total human evidence is a few hundred participants, the functional benefits observed were marginal, and it is unavailable in the US and Canada.
stanolone
Stanolone is endogenous 5-alpha-dihydrotestosterone, the most potent natural androgen receptor agonist, marketed as a transdermal gel in a small number of European markets for indications including male hypogonadism and gynaecomastia. Randomised trials in older and middle-aged men found suppression of endogenous hormones and modest body-composition change without meaningful functional benefit.
the explanation
Stanolone is the body's strongest natural male hormone, sold as a skin gel in a few European countries. In two proper trials it changed hormone levels and body fat a little, but it did not meaningfully improve strength, mobility or quality of life, and it lowered spinal bone density and raised red blood cell counts.
regulatory status
Approved in limited markets; not available in the US or Canada
Marketed as Andractim, a 2.5% hydroalcoholic transdermal gel, in several European countries including France, Belgium, Germany, Spain, Italy and the United Kingdom, with reported uses in male hypogonadism, gynaecomastia and micropenis, and historical use in advanced breast cancer. It has no US or Canadian marketing authorisation and is a controlled anabolic steroid in the US; it is prohibited in sport by WADA.
how it works · proposed mechanism
DHT is the terminal, highest-potency ligand of the androgen receptor pathway.
High-affinity androgen receptor agonism
DHT binds the androgen receptor with roughly 2-3 fold greater affinity than testosterone and activates it approximately 5-fold more potently, with slower receptor dissociation. This is why it is the dominant androgen in skin, hair follicle and prostate tissue.
No aromatisation, no estrogen arm
DHT cannot be converted to estradiol by aromatase and is not a substrate for 5-alpha-reductase, so it produces androgenic signalling entirely without estrogenic counterbalance. The Idan trial's 1.4% spinal bone mineral density loss at 24 months is consistent with that missing estrogenic contribution.
Gonadotropin and endogenous steroid suppression
Exogenous DHT exerts negative feedback on the hypothalamic-pituitary axis, and in the 24-month randomised trial it suppressed serum testosterone, estradiol, luteinizing hormone and follicle-stimulating hormone. Erythropoiesis rose in parallel, with haemoglobin increasing 7%.
what’s reported
evidence shape
5 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
The best trial of stanolone is reassuring on the risk everyone expected — prostate growth — while being unimpressive on every benefit it was supposed to deliver, and it surfaced bone density loss and polycythaemia instead. Because DHT cannot aromatise, it removes the estrogenic signalling that men depend on for skeletal maintenance, which is a structural liability rather than an incidental side effect.
key published findings
- Human trial: Idan et al (Annals of Internal Medicine, 2010), a 24-month randomised placebo-controlled trial in 114 healthy men over 50 without prostate disease using 70 mg/day transdermal DHT, found no treatment effect on prostate volume — total volume rose 29% and central volume 75% over time in both groups (P>0.2) — and PSA rose 15% over time independent of treatment.
- Human trial (adverse findings, same study): DHT reduced spinal bone mineral density by 1.4% at 24 months (P<0.001) with hip BMD unaffected, increased haemoglobin by 7% (P<0.001) causing 8 protocol discontinuations for asymptomatic elevated haematocrit that resolved on stopping, and suppressed serum testosterone, estradiol, LH and FSH.
- Human trial: Ly et al (JCEM, 2001), a 3-month randomised double-blind placebo-controlled trial in 37 older men with partial androgen deficiency (18 DHT, 19 placebo; 33 completers) using 70 mg/day transdermal DHT, found increased strength only in dominant-leg knee flexion with no change in knee extension or shoulder contraction, and no improvement in gait, balance, mobility, cognitive function or quality of life.
- Human trial (body composition, same study): DHT decreased skinfold thickness and fat mass with unchanged lean mass and unchanged waist-to-hip ratio, and left prostate volume, PSA and HDL cholesterol unchanged over the 3-month period.
- Pharmacology: DHT binds the androgen receptor with approximately 2-3 fold higher affinity and roughly 5-fold greater activation potency than testosterone, has a circulating half-life of about 53 minutes versus 34 minutes for testosterone, and can neither be aromatised to estrogen nor further reduced by 5-alpha-reductase.
limitations of the evidence
- The entire randomised human evidence base comprises roughly 150 participants across two trials, both in older or middle-aged men and both using transdermal delivery, so nothing generalises to injectable esters, to women, or to younger users.
- Neither trial was powered or long enough to detect prostate cancer incidence, cardiovascular events or fracture — the outcomes that actually matter for a potent androgen.
- No randomised evidence exists for the cosmetic and body-composition uses for which stanolone is most often sought outside licensed indications.
documented safety signals
- Polycythaemia: haemoglobin rose 7% in the 24-month randomised trial, with 8 participants discontinuing for asymptomatic elevated haematocrit.
- Spinal bone mineral density loss of 1.4% at 24 months, consistent with the absence of an aromatisable estrogenic metabolite.
- Suppression of endogenous testosterone, estradiol, LH and FSH, implying gonadal axis shutdown and, by extension, spermatogenic suppression.
- As the dominant androgen at the hair follicle and in skin, DHT is mechanistically implicated in androgenetic alopecia and acne; 5-alpha-reductase inhibitors treat pattern hair loss precisely by lowering it.
- Prostatic androgen exposure remains a theoretical concern despite the neutral 24-month prostate volume result, which was not powered for prostate cancer outcomes.
- Transdermal gels carry documented risk of secondary transfer to partners and children through skin contact.
- Controlled substance status in the US and prohibited in sport by WADA at all times.
identity
| full name | 5-alpha-dihydrotestosterone (androstanolone, stanolone) |
| category | Anabolic & Androgenic |
| modality | steroid |
| formula | C19H30O2 |
| molar mass | 290.4 g/mol |
| cas | 521-18-6 |
| half-life | Approximately 53 minutes in circulation; roughly 2.8 hours following transdermal administration. |
laboratory handling
| storage | Transdermal hydroalcoholic gel presentations are stored at room temperature away from heat and flame owing to the alcohol vehicle, and kept sealed to prevent evaporation; the steroid itself is a stable crystalline solid when protected from light. |
| solubility | Practically insoluble in water and freely soluble in ethanol and other organic solvents; the 2.5% clinical gel uses a hydroalcoholic vehicle to achieve skin penetration, and injectable presentations rely on esterification into oil-soluble prodrugs. |
| co-studied with | DHT is the terminal product of 5-alpha-reductase, so finasteride and dutasteride act by lowering it and are pharmacologically opposed to it; because it cannot aromatise, exogenous DHT provides no estradiol and concurrent aromatase inhibition would compound the estrogen deficit implicated in the observed spinal bone density loss. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
5 citedBesins Healthcare · 2026 · official
Annals of Internal Medicine · 2010 · randomized
The Journal of Clinical Endocrinology & Metabolism · 2001 · randomized
Endocrine Reviews · 2017 · reviews
Wikipedia (secondary compilation of primary pharmacology literature) · 2026 · reviews
others in Anabolic & Androgenic