“DHT Gel (20%)” is a skin gel sold as containing dihydrotestosterone (DHT, also called androstanolone) at a concentration of 20%. DHT is the body’s most potent natural androgen, and unlike testosterone it cannot be converted to estrogen. Applied to the skin, DHT is absorbed into the blood and suppresses the body’s own testosterone production.
The single most important fact: we found no approved product, published label or clinical study of a DHT gel at 20% strength. The only approved DHT gel we could verify is Andractim, a 2.5% gel authorized in France since 1981, and every human study used 0.7% or 2.5% gels. By weight, a 20% gel would hold eight times as much DHT per gram as Andractim and twice as much as the 10% gel. How much of it reaches the blood has never been measured.
This page summarizes what the French label, clinical trials of lower-strength DHT gels and regulators report, and what changes at 20%. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Class | Endogenous androgen; 5α-reduced metabolite of testosterone; not aromatized to estrogen |
| Concentration | 20%, which by weight would be 200 mg DHT per gram of gel |
| Compared with approved gel | 8 times the DHT per gram of Andractim 2.5%; twice that of a 10% gel |
| Approved products | None at 20%; the only approved DHT gel we found is Andractim 2.5% (France) |
| Route | Transdermal (applied to skin) |
| Doses studied in humans | 16–250 mg DHT/day, using 0.7% and 2.5% gels; no study used a 20% gel |
| Kinetics (0.7% gel) | Serum DHT plateaus 12–18 h after the first application; steady state by day 2–3 |
| Elimination half-life | No figure published for gel-delivered DHT |
| US status | No FDA-approved DHT product; Schedule III anabolic steroid |
| WADA status | Prohibited at all times (S1.1, androstanolone) |
What it is
DHT is testosterone with the double bond in its A-ring reduced. PubChem lists its formula as C₁₉H₃₀O₂ and its molecular weight as 290.4 g/mol (PubChem CID 10635). A gel contains DHT itself, with no ester attached, so every milligram on the label is DHT.
Because DHT cannot be aromatized, it does not raise estradiol. Estradiol tends to fall instead, because DHT suppresses the testosterone that would otherwise be converted (Wang et al., JCEM 1998; Swerdloff et al., Endocr Rev 2017). The chemistry, trials and risks of DHT gels are covered in more depth on the DHT Gel (10%) page. This page focuses on what the higher concentration changes.
What “20%” means
Andractim states its strength as 2.50 g of androstanolone per 100 g of gel, a weight-for-weight percentage (Andractim SmPC, ANSM). If a 20% gel is labeled the same way, each gram holds 200 mg DHT.
| Form | DHT per gram of gel | Relative to Andractim | Library page |
|---|---|---|---|
| 0.7% gel (research formulation) | 7 mg | ≈0.3× | Not listed separately |
| 2.5% gel (Andractim) | 25 mg | 1× | Not listed separately |
| 10% gel | 100 mg | 4× | DHT Gel (10%) |
| 20% gel | 200 mg | 8× | This page |
| Injected DHT, no ester | Not a gel | Not comparable | DHT Base |
| DHT esters, injected | Not a gel | Not comparable | DHT Propionate, DHT Enanthate |
How little gel carries a trial dose
At 20%, the DHT doses used in published studies fit into well under 2 g of gel. The table shows amounts of DHT applied to the skin, not amounts absorbed:
| DHT dose in study | Gel used in the study | Same DHT amount as 20% gel |
|---|---|---|
| 16 mg/day (Wang et al., 1998) | 2.3 g of 0.7% gel | ≈0.08 g |
| 70 mg/day (Page et al., 2011) | 10 g of 0.7% gel | ≈0.35 g |
| 125 mg/day (Andractim label, low end) | 5 g of 2.5% gel | ≈0.63 g |
| 250 mg/day (Andractim label, high end) | 10 g of 2.5% gel | ≈1.25 g |
The right-hand column assumes every gel releases the same share of its DHT. Nobody has tested that. Three points from the existing data explain why it may not hold:
- Absorption is passive. DHT crosses the skin by passive diffusion that follows Fick’s law, so flux depends on the concentration gradient and the area of skin covered (Swerdloff et al., 2017). A 20% gel changes both: far more DHT per square centimeter, spread over a much smaller area.
- In the only dose-ranging study, dose went up with area. Higher doses of the 0.7% gel were given by covering more skin: one upper arm for 16 mg, both arms and shoulders for 32 mg, and arms, shoulders and upper abdomen for 64 mg. Exposure did not rise in step with dose (6.0-, 6.9- and 16.1-fold above baseline) (Wang et al., 1998). No study has delivered a fixed dose at higher concentration over less skin.
- Labels for testosterone gels warn against swapping strengths. The AndroGel 1% label states that topical products with different doses, strengths or application instructions may produce different systemic exposure. It also states that about 10% of applied testosterone is absorbed (AndroGel 1% label). No equivalent absorption figure has been published for any DHT gel.
Small measuring errors also matter more at 20%. An extra 0.5 g of gel adds 100 mg DHT, about the same as the 70 mg/day used in the long-term trials. This is simple arithmetic, not a measured outcome.
How it behaves in the body
No pharmacokinetic study of a 20% DHT gel exists, and Andractim’s label leaves its pharmacokinetics section blank (“non renseigné”) (Andractim SmPC, ANSM). Data from 0.7% and 2.5% gels show:
| Finding | Detail | Source |
|---|---|---|
| Time to plateau | Serum DHT rose gradually and plateaued 12–18 h after the first application | Wang et al., 1998 |
| Steady state | Reached by day 2–3 of daily use | Wang et al., 1998 |
| Serum DHT at steady state | 8–11, 12–17 and 14–24 nmol/L at 16, 32 and 64 mg/day | Wang et al., 1998 |
| Skin reservoir | 125 mg in 5 g gel raised plasma DHT 4–5 times; levels were stable 2–21 h after the last dose | Fiet et al., Int J Androl 1982 |
| Twice-daily use | 125 mg twice daily gave stable levels apart from a small DHT dip 12 h after the previous dose | Kuhn et al., JCEM 1984 |
None of these studies reports an elimination half-life for gel-delivered DHT, so we do not give one. The 12–18 hour figure is the time for levels to plateau after a first dose, not a half-life.
Approved medical use
No DHT product of any strength is approved in the United States. A 2017 review noted that a single transdermal DHT product is available in a handful of countries and is the formulation used in clinical trials (Swerdloff et al., 2017).
In France, Andractim 2.5% (Besins Healthcare) was authorized on January 23, 1981. It is prescription-only (List I), must be started by a specialist in endocrinology, urology, gynecology or dermatology, and has these labeled uses (Andractim SmPC, ANSM):
| Use | Labeled dose (2.5% gel) | DHT amount | Same DHT as 20% gel |
|---|---|---|---|
| Androgen deficiency in men, including hypogonadism, on chest and/or abdomen | 5–10 g gel daily; do not wash the area for 6 hours | 125–250 mg/day | ≈0.63–1.25 g |
| Local treatment of lichen sclerosus and gynecomastia in men, and vulvar lichen sclerosus in women | 2.5 g every other day on the affected area, avoiding mucous membranes | ≈62.5 mg per application | ≈0.31 g |
French health insurance reimburses Andractim only for idiopathic gynecomastia in men, and France’s Transparency Commission rated its medical benefit there as “low” in 2013 (Andractim SmPC, ANSM). Nothing on the label covers a 20% gel.
What the research shows
Every controlled trial used 0.7% or 2.5% gel. None tested a 20% gel, and none studied DHT gel in young trained men or for athletic performance. The main trials, described in more detail on the DHT Gel (10%) page:
| Trial | Design, n | DHT dose and duration | Main findings |
|---|---|---|---|
| Vermeulen & Deslypere, Maturitas 1985 | Older men with relatively low testosterone | 125 or 250 mg/day (Andractim), 3 months | LH suppressed; total and LDL cholesterol fell moderately; HDL fell slightly |
| Ly et al., JCEM 2001 | RCT, 37 men 60+ with testosterone ≤15 nmol/L | 70 mg/day, 3 months | Fat mass fell; lean mass unchanged; only dominant knee flexion strength rose |
| Kunelius et al., JCEM 2002 | RCT, 120 men aged 50–70 | 125–250 mg/day, 6 months | Ability to maintain erection improved; well-being unchanged; hemoglobin and hematocrit rose |
| Idan et al., Ann Intern Med 2010 | RCT, 114 healthy men over 50 | 70 mg/day, 24 months | No effect on prostate growth; lean mass +2.4%, fat mass −5.2% vs placebo; spinal bone density −1.4% |
| Page et al., JCEM 2011 | RCT, 31 healthy men aged 35–55 | 70 mg/day (10 g of 0.7% gel), 4 weeks | Serum DHT up nearly 7-fold; DHT inside the prostate unchanged |
| Sartorius et al., J Sex Med 2014 | Same 24-month trial as Idan, 114 men | 70 mg/day, 24 months | No effect on 33 sexual function and mood measures except a mild, reversible drop in desire |
Two patterns stand out. The body-composition effects were modest even after 2 years of use in older men. And the prostate, the main concern with DHT, did not grow faster on DHT than on placebo, although the authors noted this cannot rule out effects on an existing cancer (Idan et al., 2010).
The local uses behind the French label also used 2.5% gel. In an uncontrolled series of 40 men with long-standing gynecomastia, 125 mg twice daily led to complete disappearance in 10 and partial regression in 19 (Kuhn et al., Clin Endocrinol 1983). In 23 children with micropenis, doses of 0.1–0.3 mg/kg/day were titrated to keep DHT in the normal range (Xu et al., J Pediatr Endocrinol Metab 2017). Weight-based pediatric doses that small would amount to only milligrams of a 20% gel, which could not be measured accurately with normal dosing tools. That is an inference from the arithmetic, not a tested finding.
Side effects and risks
The French label lists raised hematocrit, red cell count and hemoglobin as common side effects. Other effects are those of excess androgen activity, which the label says can be controlled by lowering the dose (Andractim SmPC, ANSM). Because a 20% gel’s absorption is unknown, the dose actually delivered, and so the size of these effects, cannot be predicted from the trials.
Shutdown of natural testosterone and estradiol
Every DHT gel study that measured it found suppression of the body’s own hormones:
- In 12 healthy men, 125 mg twice daily for 10 days lowered testosterone from 7.33 to 1.33 ng/mL, with LH and estradiol also falling (Kuhn et al., JCEM 1984).
- Suppression was dose-dependent over 14 days: own testosterone exposure fell to 75%, 56% and 36% of baseline at 16, 32 and 64 mg/day (Wang et al., 1998).
- After 24 months on 70 mg/day, mean serum testosterone was about 86% lower (Swerdloff et al., 2017), and testosterone, LH, FSH and estradiol were completely suppressed throughout (Sartorius et al., 2014).
Because DHT cannot become estradiol, estradiol falls too. The 1.4% loss of spinal bone density over 2 years is attributed to this estrogen deficiency (Idan et al., 2010; Sartorius et al., 2014).
Red blood cells
DHT raises hematocrit (the share of blood made up of red cells):
- In the 6-month trial at 125–250 mg/day, hematocrit rose from 43.5% to 45.8% and hemoglobin from 146.0 to 154.8 g/L (Kunelius et al., 2002).
- In the 2-year trial at 70 mg/day, hemoglobin rose 7% (95% CI 5–9) vs placebo. Eight men stopped because of an asymptomatic hematocrit rise, which resolved after stopping, and 3 stopped because PSA rose; none had prostate cancer (Idan et al., 2010).
Lipids and liver
In the gel trials, lipids did not worsen. Total and LDL cholesterol fell with HDL unchanged at 70 mg/day (Ly et al., 2001), and the 6-month trial found no effect on liver function or lipids (Kunelius et al., 2002). An earlier Andractim study found a slight HDL fall alongside lower total and LDL cholesterol (Vermeulen & Deslypere, 1985). These results apply to doses of 70–250 mg/day; they say nothing about higher or unknown exposures.
Skin
Trials reported no skin effects beyond mild irritation from the high alcohol content, and no link to acne or male-pattern hair loss over 24 months (Swerdloff et al., 2017). The 14-day dose-ranging study saw no skin irritation at all (Wang et al., 1998). Andractim is 48.8% ethanol by weight, can burn on damaged skin and is flammable until dry (Andractim SmPC, ANSM). The vehicle of an unapproved 20% gel is not standardized, and its effects on the skin are unstudied.
Transfer to other people
US testosterone gels carry a boxed warning: virilization has been reported in children secondarily exposed to the gel, and children should avoid contact with unwashed or unclothed application sites (AndroGel 1% label). Transfer of DHT gel has not been studied. A 20% gel places eight times as much hormone per gram on the skin as Andractim, concentrated on a smaller area, so the hormone left on unwashed skin or hands could be correspondingly concentrated. This is an inference, not a measured result.
Who should not use it
The Andractim label lists these contraindications and precautions (Andractim SmPC, ANSM):
- prostate cancer in men;
- systemic androgen therapy in women, because of the risk of virilization;
- pregnancy, possible pregnancy and breastfeeding;
- caution in severe heart, liver or kidney failure, ischemic heart disease, high blood pressure, and thrombophilia or risk factors for venous blood clots.
It also flags an interaction with vitamin K antagonists such as warfarin, which raises bleeding risk and calls for closer INR monitoring. During long-term use, the label calls for regular checks of hemoglobin, hematocrit, liver function and lipids.
Legal status and use outside medicine
- United States. No DHT product is FDA-approved. DHT is listed in Schedule III as “4-dihydrotestosterone (17β-hydroxy-androstan-3-one)” (21 CFR 1308.13).
- Sport. WADA lists androstanolone (5α-dihydrotestosterone) under S1.1 anabolic androgenic steroids, prohibited in and out of competition when administered exogenously (WADA 2026 Prohibited List). The Andractim label itself warns athletes that it can cause a positive doping test.
- Product quality. No regulator has approved a 20% DHT gel, so products sold at that strength have no verified label for DHT content, vehicle or absorption.
Key takeaways
- No approved product or study at this strength. The only approved DHT gel we found is Andractim 2.5% in France, and all clinical data come from 0.7% and 2.5% gels.
- Eight times the DHT per gram of the approved gel. At 20% by weight, 1 g carries 200 mg DHT, so trial doses of 70–250 mg correspond to about 0.35–1.25 g of gel, and small measuring errors add large amounts of hormone.
- Absorption at 20% is unknown. DHT crosses skin by passive diffusion that depends on concentration and area, and no study has measured how much a high-concentration, small-area application delivers.
- Strong, dose-dependent suppression. DHT gels suppressed LH, the body’s own testosterone and estradiol in every study that measured them.
- Modest effects, known risks at studied doses. Two years of 70 mg/day in men over 50 raised lean mass 2.4% and cut fat mass 5.2% vs placebo, raised hemoglobin 7% and lowered spinal bone density 1.4%, without affecting prostate growth.
- Controlled and banned in sport. DHT is Schedule III in the US and prohibited at all times by WADA.
Sources
- Agence nationale de sécurité du médicament et des produits de santé (ANSM). Andractim, gel pour application locale (androstanolone 2.5%): résumé des caractéristiques du produit and notice. Updated December 10, 2025. ANSM.
- National Center for Biotechnology Information. Dihydrotestosterone, PubChem CID 10635. PubChem.
- Swerdloff RS, Dudley RE, Page ST, Wang C, Salameh WA. Dihydrotestosterone: biochemistry, physiology, and clinical implications of elevated blood levels. Endocr Rev. 2017;38(3):220–254. PubMed; PMC.
- Wang C, Iranmanesh A, Berman N, et al. Comparative pharmacokinetics of three doses of percutaneous dihydrotestosterone gel in healthy elderly men–a clinical research center study. J Clin Endocrinol Metab. 1998;83(8):2749–2757. PubMed.
- Fiet J, Morville R, Chemama D, et al. Percutaneous absorption of 5 alpha-dihydrotestosterone in man. I. Plasma androgen and gonadotrophin levels in normal adult men after percutaneous administration of 5 alpha-dihydrotestosterone. Int J Androl. 1982;5(6):586–594. PubMed.
- Kuhn JM, Rieu M, Laudat MH, et al. Effects of 10 days administration of percutaneous dihydrotestosterone on the pituitary-testicular axis in normal men. J Clin Endocrinol Metab. 1984;58(2):231–235. PubMed.
- Vermeulen A, Deslypere JP. Long-term transdermal dihydrotestosterone therapy: effects on pituitary gonadal axis and plasma lipoproteins. Maturitas. 1985;7(3):281–287. PubMed.
- Ly LP, Jimenez M, Zhuang TN, et al. A double-blind, placebo-controlled, randomized clinical trial of transdermal dihydrotestosterone gel on muscular strength, mobility, and quality of life in older men with partial androgen deficiency. J Clin Endocrinol Metab. 2001;86(9):4078–4088. PubMed.
- Kunelius P, Lukkarinen O, Hannuksela ML, Itkonen O, Tapanainen JS. The effects of transdermal dihydrotestosterone in the aging male: a prospective, randomized, double blind study. J Clin Endocrinol Metab. 2002;87(4):1467–1472. PubMed.
- Idan A, Griffiths KA, Harwood DT, et al. Long-term effects of dihydrotestosterone treatment on prostate growth in healthy, middle-aged men without prostate disease: a randomized, placebo-controlled trial. Ann Intern Med. 2010;153(10):621–632. PubMed.
- Page ST, Lin DW, Mostaghel EA, et al. Dihydrotestosterone administration does not increase intraprostatic androgen concentrations or alter prostate androgen action in healthy men: a randomized-controlled trial. J Clin Endocrinol Metab. 2011;96(2):430–437. PubMed.
- Sartorius GA, Ly LP, Handelsman DJ. Male sexual function can be maintained without aromatization: randomized placebo-controlled trial of dihydrotestosterone (DHT) in healthy, older men for 24 months. J Sex Med. 2014;11(10):2562–2570. PubMed.
- Kuhn JM, Roca R, Laudat MH, et al. Studies on the treatment of idiopathic gynaecomastia with percutaneous dihydrotestosterone. Clin Endocrinol (Oxf). 1983;19(4):513–520. PubMed.
- Xu D, Lu L, Xi L, et al. Efficacy and safety of percutaneous administration of dihydrotestosterone in children of different genetic backgrounds with micropenis. J Pediatr Endocrinol Metab. 2017;30(12):1285–1291. PubMed.
- ASCEND Therapeutics US. AndroGel (testosterone gel) 1%, prescribing information. Revised October 2025. DailyMed.
- US Drug Enforcement Administration. Schedules of controlled substances: Schedule III, 21 CFR 1308.13(f). eCFR.
- World Anti-Doping Agency. The 2026 Prohibited List, International Standard. In effect January 1, 2026. WADA 2026 Prohibited List.