Testosterone propionate is testosterone with a short propionic-acid ester attached at the 17β position. It was the first injectable testosterone ester in clinical use; the longer-acting testosterone enanthate followed in the mid-1950s. Because a single injection raises testosterone for only a day or two, it needs far more frequent injections than longer esters.
In the US, every human testosterone propionate product listed in Drugs@FDA is now marked discontinued. In the UK it survives as one of four esters in Sustanon 250, and in the US it is still sold in an FDA-approved cattle implant. It is an anabolic-androgenic steroid (AAS) and is banned in sport.
This page summarizes what drug labels, regulators and the (mostly older) clinical studies report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Androgen; anabolic-androgenic steroid (testosterone ester) |
| Chemistry | Testosterone 17β-propionate, C₂₂H₃₂O₃, 344.5 g/mol |
| Testosterone content | ≈84% of the ester’s weight (100 mg ester ≈ 84 mg testosterone) |
| Route | Intramuscular injection in oil; a 2% topical form was used in older skin trials |
| US human products | Generic injections of 25, 50 and 100 mg/mL; all listed as discontinued |
| Current labeled human use | UK: 30 mg per 1 mL ampoule of Sustanon 250 (with three other esters) |
| Duration / half-life | No current label gives a half-life. Testosterone stayed above the lower normal limit ≈1 day after 25 mg and ≈2 days after 50 mg |
| US schedule | Schedule III controlled substance (testosterone, including its esters) |
| WADA status | Prohibited at all times (S1.1 anabolic androgenic steroids) |
What it is
Testosterone was isolated and first synthesized in 1935. It is inactive when swallowed, so it was first given as implanted pellets and then as injectable esters: first testosterone propionate, described as having “a short half-life,” and from the mid-1950s the longer-acting enanthate, which became the main preparation for half a century (Nieschlag & Nieschlag, Asian J Androl 2014).
The ester itself has no hormonal activity. Once it is cleaved off, what remains is ordinary testosterone. Testosterone esters are less polar than free testosterone, so when injected in oil they are absorbed slowly from the oil depot (Depo-Testosterone label). Propionate is one of the shortest esters in use, consistent with the brief action seen in the studies below.
The smaller ester also means more testosterone per milligram. Using PubChem molecular weights (PubChem):
| Compound | Molecular weight | Testosterone share by weight |
|---|---|---|
| Testosterone | 288.4 g/mol | 100% |
| Testosterone propionate | 344.5 g/mol | ≈84% |
| Testosterone enanthate | 400.6 g/mol | ≈72% |
| Testosterone cypionate | 412.6 g/mol | ≈70% |
After release, testosterone acts on the androgen receptor directly and is also converted to dihydrotestosterone (DHT) and estradiol (Sustanon 250 SmPC).
Is propionate a “drier” testosterone? Propionate is often described as causing less water retention or fewer estrogenic effects than longer esters. We found no human study comparing esters on these outcomes at equal testosterone doses. Once the ester is removed, the hormone is the same testosterone, which the label says is metabolized to estradiol. Any difference would come from dosing pattern and blood levels, not from the propionate group itself.
Pharmacokinetics
The key human data are short single-dose studies from the 1970s and 1980s:
| Study | Dose | Finding |
|---|---|---|
| Normal and hypogonadal men (Nieschlag et al., Horm Res 1976) | 25 mg propionate IM | Testosterone above the lower normal limit for 1 day |
| Same study | 50 mg propionate IM | Above the lower normal limit for 2 days |
| Same study | 250 mg enanthate IM | Above the lower normal limit for 14 days |
| Normal men, deuterium-labeled drug (Fujioka et al., JCEM 1986) | 25 mg propionate IM | Intact ester measurable in plasma at 2–4 ng/mL from 3 to 36 h; testosterone from the dose above the physiological level for 48 h |
| 3 men with hypogonadotropic hypogonadism (Fujioka et al., Chem Pharm Bull 1989) | Single IM dose | Testosterone from the dose above 4 ng/mL (400 ng/dL) for 48 h |
In the 1976 study, LH (the pituitary signal that drives the testes) was suppressed for the same periods that testosterone was raised. The labeled kinetics of Sustanon 250 describe the four-ester mixture as a whole, not propionate alone: peak total testosterone of about 70 nmol/L at 24–48 h, returning to the lower normal limit after about 21 days (Sustanon 250 SmPC).
We could not find a current regulatory label or primary study that states a terminal half-life for injected testosterone propionate. Secondary sources quote figures that disagree with each other, so we do not repeat one here. What the primary data show is a duration of action of roughly 1–2 days per injection at 25–50 mg.
Regulatory status and medical use
United States
Drugs@FDA lists generic testosterone propionate injections from several manufacturers at 25, 50 and 100 mg/mL. One of them (ANDA 080188) was approved in 1974. Every listed product is marked “Discontinued,” and Drugs@FDA has no label on file for ANDA 080188 (Drugs@FDA, ANDA 080188). There is therefore no current US human label with an approved dose.
The only testosterone propionate product on DailyMed is veterinary. Synovex H is an ear implant for beef heifers containing 200 mg testosterone propionate and 20 mg estradiol benzoate, approved under NADA 011-427 to increase weight gain and feed efficiency. Its label states “Not for use in humans” (Synovex H label).
United Kingdom: Sustanon 250
Sustanon 250 is a current UK product. Each 1 mL ampoule in arachis (peanut) oil contains (Sustanon 250 SmPC):
| Ester | Amount |
|---|---|
| Testosterone propionate | 30 mg |
| Testosterone phenylpropionate | 60 mg |
| Testosterone isocaproate | 60 mg |
| Testosterone decanoate | 100 mg |
| Total testosterone | 176 mg |
It is licensed for testosterone replacement in men with confirmed hypogonadism and as supportive therapy for female-to-male transgender people. The usual adult dose is one 1 mL injection every 3 weeks. In this mixture, propionate is the fast-acting part.
What the research shows
Testosterone propionate has almost no modern clinical trial record. Most human data come from small, older studies. Animal studies are not covered here.
Muscle and strength
We found no controlled trial of injectable testosterone propionate on muscle mass or strength. The best evidence on testosterone and muscle comes from trials of testosterone enanthate. After the ester is removed, it delivers the same hormone, so these results apply in terms of testosterone dose, not ester:
- In 43 normal men, 600 mg/week of testosterone enanthate for 10 weeks plus weight training increased fat-free mass by 6.1 kg, bench press by 22 kg and squat by 38 kg. Testosterone without training also beat placebo (Bhasin et al., NEJM 1996).
- In 61 young men whose own testosterone was suppressed, weekly enanthate at 125, 300 and 600 mg for 20 weeks raised fat-free mass by 3.4, 5.2 and 7.9 kg. The gain correlated with the logarithm of the testosterone level (r = 0.73). HDL cholesterol fell and hemoglobin rose as levels went up (Bhasin et al., AJP-Endo 2001).
Male hormonal contraception (historical)
Propionate was used in early studies of testosterone as a male contraceptive:
- Seven healthy men given 25 mg/day testosterone propionate by injection for 60 days had no sperm in their ejaculate by the end of treatment. Sperm counts returned to normal about 150 days after stopping. This was a small, uncontrolled study reported as a conference abstract (Reddy, J Reprod Fertil 1974).
- In trials combining monthly depot medroxyprogesterone acetate with testosterone propionate implants or enanthate injections, partners of 9 men became pregnant even though the men’s recent sperm counts were 10 million/mL or lower. The authors concluded that this approach may need complete absence of sperm to work (Barfield et al., Contraception 1979).
Breast cancer in women (historical)
A 1978 review described androgens as effective agents for metastatic breast cancer in postmenopausal women. It reported that early studies with testosterone propionate showed objective tumor regression in slightly more than 20% of women. Later synthetic androgens did not clearly improve on it (Brodkin & Cooper, Ann Intern Med 1978).
Topical use in genital lichen sclerosus
Testosterone propionate 2% ointment or cream was widely used in the past on vulvar lichen sclerosus, a chronic inflammatory skin disease. A Cochrane review of randomized trials found it did not work (Chi et al., Cochrane 2011):
| Comparison | Result |
|---|---|
| Testosterone vs placebo (2 trials pooled) | No significant benefit for symptom improvement: RR 1.21 (95% CI 0.56–2.64) |
| Testosterone vs clobetasol propionate 0.05% (1 trial, 3 months) | Testosterone less effective: RR 0.67 (95% CI 0.45–0.98) for symptom improvement |
| Testosterone as maintenance after clobetasol (1 trial, 32 women, 24 weeks) | Symptoms worsened on testosterone but not on placebo |
The review’s background notes that androgen side effects such as excess hair growth and clitoral enlargement were common with topical testosterone. The review found evidence of benefit for topical corticosteroids such as clobetasol instead.
Side effects and risks
No current label covers testosterone propionate alone. The risks below come from current labels for other testosterone injections, which deliver the same hormone.
Class effects from testosterone labels
The Depo-Testosterone label lists these warnings and adverse reactions for testosterone (Depo-Testosterone label):
- polycythemia (a high red blood cell count), with periodic hematocrit checks advised;
- increases in blood pressure, which can raise cardiovascular risk over time;
- venous thromboembolism (deep vein thrombosis and pulmonary embolism) in postmarketing reports;
- edema, which may be serious in people with heart, kidney or liver disease;
- gynecomastia (breast tissue growth in men);
- acne, male-pattern hair loss and changes in libido;
- inflammation and pain at the injection site;
- increased sensitivity to oral anticoagulants such as warfarin, and possible lower insulin needs in people with diabetes.
Hematocrit
Hematocrit (the share of blood made up of red cells) rises on all forms of testosterone. A network meta-analysis of 29 randomized trials (3,393 men) found a mean rise of 4.0% (95% CI 2.9–5.1) with intramuscular enanthate or cypionate, among the largest rises of the formulations tested (Nackeeran et al., J Urol 2022). No propionate trials were included. The Sustanon 250 SmPC advises checking hematocrit and hemoglobin before treatment, every 3 months in the first year and yearly after that.
Hormonal suppression and fertility
Injected testosterone switches off the body’s own production. In the 1976 study, LH was suppressed for as long as propionate kept testosterone raised. At 25 mg/day, propionate stopped sperm production in all seven men in the 1974 study, with recovery taking about 5 months. The cypionate label notes that sperm production may be suppressed through feedback on FSH.
Abuse at high doses
The testosterone label describes abuse at doses above those approved, often together with other AAS. Reported serious effects include cardiac arrest, heart attack, hypertrophic cardiomyopathy, heart failure, stroke, liver toxicity and psychiatric effects such as major depression, mania, aggression and psychosis. In men, testicular shrinkage and infertility are also reported. In women, the label lists excess hair growth, voice deepening, clitoral enlargement, male-pattern baldness and menstrual changes.
Who should not use it
Combining the Sustanon 250 SmPC and the Depo-Testosterone label, testosterone injections are contraindicated in:
- known or suspected prostate or breast cancer in men;
- pregnancy and breastfeeding;
- serious heart, liver or kidney disease;
- for Sustanon 250 specifically, allergy to peanut or soya, because the carrier is arachis oil.
Legal status and use outside medicine
- US. Testosterone is a Schedule III anabolic steroid, and the listing covers its salts, esters and ethers (21 CFR 1308.13). The federal definition excludes steroids approved for implantation in cattle, such as Synovex H, unless someone prescribes or distributes them for human use (21 CFR 1300.01).
- Sport. The 2026 WADA Prohibited List bans testosterone, and substances with similar structure or effect “including their esters,” at all times when given exogenously (WADA 2026 List).
- Supply. With no US human product on the market, testosterone propionate sold for human use in the US comes from outside the regulated drug supply, with no assurance of dose, sterility or identity.
Key takeaways
- The original short-acting ester. Propionate was the first injectable testosterone ester in clinical use. Enanthate, introduced in the mid-1950s, became the main preparation.
- Effects last 1–2 days per dose. After 25–50 mg, testosterone stayed above the lower normal limit for only 1–2 days, compared with about 14 days after 250 mg enanthate.
- More testosterone per milligram. About 84% of the ester’s weight is testosterone, versus about 70–72% for cypionate and enanthate.
- No current US human product. All US injections are discontinued; the main labeled human use today is as 30 mg of the 250 mg in Sustanon 250.
- Same hormone, same risks. Higher hematocrit, blood pressure changes, lower HDL, gynecomastia and suppression of sperm production apply as for any injected testosterone.
Sources
- National Center for Biotechnology Information. Testosterone propionate, PubChem CID 5995. PubChem.
- Nieschlag E, Nieschlag S. Testosterone deficiency: a historical perspective. Asian J Androl. 2014;16(2):161–168. PubMed; PMC.
- Pfizer. Depo-Testosterone (testosterone cypionate) injection, prescribing information, revised September 2025. DailyMed.
- Aspen Pharma Trading Limited. Sustanon 250, 250 mg/ml solution for injection, Summary of Product Characteristics. emc.
- Food and Drug Administration. Drugs@FDA: ANDA 080188, testosterone propionate injection. FDA.
- Zoetis Inc. Synovex H (testosterone propionate and estradiol benzoate) implant, NADA 011-427, label. DailyMed.
- Nieschlag E, Cüppers HJ, Wiegelmann W, Wickings EJ. Bioavailability and LH-suppressing effect of different testosterone preparations in normal and hypogonadal men. Horm Res. 1976;7(3):138–145. PubMed.
- Fujioka M, Shinohara Y, Baba S, Irie M, Inoue K. Pharmacokinetic properties of testosterone propionate in normal men. J Clin Endocrinol Metab. 1986;63(6):1361–1364. PubMed.
- Fujioka M, Shinohara Y, Baba S, Irie M, Inoue K. Endogenous and exogenous testosterone levels after administration of deuterium-labelled testosterone propionate in hypogonadotropic hypogonadism. Chem Pharm Bull (Tokyo). 1989;37(11):3100–3101. PubMed.
- Bhasin S, Storer TW, Berman N, et al. The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men. N Engl J Med. 1996;335(1):1–7. PubMed.
- Bhasin S, Woodhouse L, Casaburi R, et al. Testosterone dose-response relationships in healthy young men. Am J Physiol Endocrinol Metab. 2001;281(6):E1172–E1181. PubMed.
- Reddy PR. Proceedings: Reversible contraceptive action of testosterone in males. J Reprod Fertil. 1974;38(1):232. PubMed.
- Barfield A, Melo J, Coutinho E, et al. Pregnancies associated with sperm concentrations below 10 million/ml in clinical studies of a potential male contraceptive method, monthly depot medroxyprogesterone acetate and testosterone esters. Contraception. 1979;20(2):121–127. PubMed.
- Brodkin RA, Cooper MR. Calusterone. Ann Intern Med. 1978;89(6):945–948. PubMed.
- Chi CC, Kirtschig G, Baldo M, et al. Topical interventions for genital lichen sclerosus. Cochrane Database Syst Rev. 2011;(12):CD008240. PubMed; PMC.
- Nackeeran S, Kohn T, Gonzalez D, et al. The effect of route of testosterone on changes in hematocrit: a systematic review and Bayesian network meta-analysis of randomized trials. J Urol. 2022;207(1):44–51. PubMed.
- Drug Enforcement Administration. 21 CFR 1300.01 (definition of anabolic steroid) and 21 CFR 1308.13(f) (Schedule III anabolic steroids). eCFR 1300.01; eCFR 1308.13.
- World Anti-Doping Agency. The 2026 Prohibited List, valid 1 January 2026. WADA.