Injectable AAS / IM, SubQ / 50-150mg EOD
Testosterone Propionate
Testosterone propionate is the oldest testosterone product still in use. The ester appears in the literature in 1936, the year after testosterone was synthesized, and it was the first injectable form sold as a drug; almost everything that came after it was an attempt to make the injections less frequent.
In plain words
Testosterone propionate is testosterone carrying the shortest chemical tail in routine use, which makes it oil-soluble enough to form a depot in the muscle but lets that depot drain in days rather than weeks. It is the oldest testosterone product still in use: the ester appears in the literature in 1936, the year after testosterone itself was synthesized, and reached the market in 1937 as the first injectable testosterone sold as a drug. Its clinical record is long and varied - replacement treatment for men from 1937, an uncontrolled hospital series for advanced breast carcinoma in 1946, and a 2 percent ointment for a vulvar skin condition that a later controlled comparison found clearly worse than the treatment it was tested against. The human pharmacology has been measured directly: a single 25 mg injection into muscle held testosterone above the physiological range for about 48 hours, and labeled-tracer work showed that the tail is cleaved off in the body, so what acts is plain testosterone. The longer esters were built precisely so injections would not be needed every few days, and they displaced it almost completely; the human injectable is now discontinued in the United States, where testosterone and its esters are Schedule III controlled substances, so most propionate in use today comes from outside pharmacies.
At a glance
| Half-life | 1.04 days |
|---|---|
| Tmax | 1.06 days |
| Route(s) | IM, SubQ |
| Published dosing range | 50-150mg EOD |
Reference data from the DosePlot canon -- not a protocol recommendation.
Serum curve
Single 100 mg dose by IM, rendered from the same engine that powers the interactive chart. Relative levels, not lab values.
What does the evidence show?
Two things are labeled separately here because they answer different questions. The tier is how a study was built. The distance chips are whether that study touched this molecule, by this route, in a population resembling the reader. A randomized trial of a different molecule keeps its tier and still says nothing about this compound.
| Finding | Tier | Distance from use | Study |
|---|---|---|---|
| A single 25 mg intramuscular injection of testosterone propionate held serum testosterone above the physiological range for about 48 hours in healthy men, with the intact ester measurable in plasma between 3 and 36 hours after the injection. | clinical | not recorded | Fujioka M, Shinohara Y, Baba S, Irie M, Inoue K. Pharmacokinetic properties of testosterone propionate in normal men.Journal of Clinical Endocrinology and Metabolism 63(6):1361-1364, 1986 |
| The propionate group is cleaved off in the body, so what circulates and acts on the receptor is testosterone itself. Deuterium-labeled tracing showed labeled testosterone appearing in plasma after the injection while endogenous testosterone changed little, which is the direct demonstration that the ester sets the time course and not the effect. | clinical | not recorded | Fujioka M, Shinohara Y, Baba S, Irie M, Inoue K. Pharmacokinetic properties of testosterone propionate in normal men.Journal of Clinical Endocrinology and Metabolism 63(6):1361-1364, 1986 |
| Injected testosterone propionate was used as a hormonal treatment for advanced breast carcinoma in the 1940s, with regressions reported in an uncontrolled hospital series. The series has no control group, so it records response under treatment rather than benefit against no treatment. It was also not the compound's first therapeutic use: propionate had been given for male hypogonadism since 1937, about nine years earlier, as the next claim's 1938 report records. | clinical | not recorded | Adair FE, Herrmann JB. The use of testosterone propionate in the treatment of advanced carcinoma of the breast.Annals of Surgery 123(6):1023-1035, 1946 |
| Replacement dosing with injected testosterone propionate is documented from 1937. A clinical report published the following year describes a 38-year-old man whose testicles had been destroyed by a war wound and who was treated with daily 20 mg injections of testosterone propionate, developed painful priapism within a week, and was then held on 40 mg weekly. The same report gives about 40 mg every two weeks for prostatic hypertrophy, paired with a small dose of estradiol benzoate. Its author thanks Schering for supplying Testoviron, without tying it to any particular case. That is nine years before the breast-carcinoma series above, so replacement dosing is the earlier use of the two in the published record. | clinical | not recorded | Foss GL. Some clinical applications of the male and female sex hormones.Bristol Medico-Chirurgical Journal 55(207):23-42, 1938 |
| As a 2 percent ointment, testosterone propionate was a standard treatment for vulvar lichen sclerosus until a two-arm comparison of 20 women per group found it clearly inferior to clobetasol: 70 percent of the testosterone group stopped treatment for lack of response, against 10 percent of the clobetasol group, and signs and symptoms were better in the clobetasol arm at one year. The published abstract describes only the group sizes and the follow-up schedule, without stating that patients were randomized or blinded, and the bibliographic records assign it no randomized-trial publication type and no randomization subject heading. The full text is paywalled and was not read. It is treated here as a controlled comparison rather than a randomized trial. | clinical | not recorded | Bornstein J, Heifetz S, Kellner Y, Stolar Z, Abramovici H. Clobetasol dipropionate 0.05% versus testosterone propionate 2% topical application for severe vulvar lichen sclerosus.American Journal of Obstetrics and Gynecology 178(1 Pt 1):80-84, 1998 |
| In castrated rats, testosterone propionate is the reference androgen used to weigh anabolic effect (levator ani and bulbocavernosus muscles) against androgenic effect (ventral prostate, seminal vesicles, Cowper's glands, glans penis). The multi-laboratory program that standardized the modern form of that assay ran a dose-response phase across 17 laboratories in 7 countries, then a seven-laboratory phase that paired reference propionate doses of 0.2 and 0.4 mg per kg of body weight per day against an antagonist. Every laboratory whose data were retained detected the expected weight increases; one laboratory dosed in micrograms per kilogram rather than milligrams, saw no effect at all, and its data were excluded. | preclinical | not recorded | Owens W, Zeiger E, Walker M, Ashby J, Onyon L, Gray LE. The OECD program to validate the rat Hershberger bioassay to screen compounds for in vivo androgen and antiandrogen responses. Phase 1: use of a potent agonist and a potent antagonist to test the standardized protocol.Environmental Health Perspectives 114(8):1259-1265, 2006 |
| Community protocols run propionate daily or every other day almost without exception. Reports from people who stretched the interval to every third day or longer describe the trough as a drop in mood and energy in the last day before the next injection, which is the pattern the short ester predicts. | anecdotal | not recorded | community reports aggregated from reddit, MESO-Rx, and similar forumsno study |
| Propionate is widely reported to sting during and after the injection more than the longer esters, with soreness at the site lasting a day or two. Reports attribute it to the solvent load rather than to the hormone. That attribution is untested here: a search of the indexed literature for a head-to-head comparison of injection-site pain between testosterone esters returned none, so the explanation rests on reports rather than on measurement. | anecdotal | not recorded | community reports aggregated from reddit, MESO-Rx, and similar forumsno study |
How did it get here?
- preclinical1935
- Testosterone is isolated and then synthesized (Laqueur, Butenandt, Ruzicka). Work on esters that slow release from an oil depot follows, and propionic acid gives the shortest of the practical tails.
- first-human1936-1937
- The propionate ester appears in the published literature in 1936, a year after the synthesis, and reaches the market in 1937 as Schering's Testoviron, the first injectable testosterone sold as a drug. It is used for eunuchoidism and hypogonadism, and the schedule is two or three injections a week from the beginning, because the depot is empty by then.
- clinical-adoption1946
- A Memorial Hospital series reports testosterone propionate for advanced breast carcinoma. Androgen therapy enters oncology, and the propionate is the ester it enters on.
- clinical-adoption1951-1960s
- Cypionate appears in the literature in 1951 and enanthate in 1954, with depots that last one to three weeks. For replacement therapy they displace propionate almost completely, on dosing frequency alone; the molecule released into the blood is identical.
- grey-market1990s-present
- Non-medical use of injectable testosterone esters in sport and bodybuilding was established well before this point. The United States answers with the Anabolic Steroid Control Act of 1990, which puts testosterone and its esters in Schedule III of the Controlled Substances Act, where they remain. The human injectable is discontinued in the United States, whose current drug listings carry propionate only as a bulk ingredient and in a cattle implant, and it remains on sale in a handful of other countries. Most propionate used today comes from outside pharmacies, chosen for fast onset and a fast washout when a dose has to be stopped, and the buyer accepts the injection schedule the clinics abandoned. In regulated pharmacy it survives mainly as the fast-acting component of blended testosterone oils.
How is it made?
Production happens in three stages.
1. Making the testosterone. Commercial testosterone is not extracted from animals but semi-synthesized from plant sterols, usually soy phytosterols or diosgenin from wild yam: industrial chemistry cuts the plant molecule down to a bare steroid core, then converts it to testosterone in a few well-established steps. The same route supplies most steroid medicines.
2. Attaching the propionate ester. Testosterone is reacted with propionic anhydride, which bonds a three-carbon tail at the 17-beta position, the shortest ester tail in routine use. The tail makes the molecule oil-soluble so it sits as a depot in the muscle, but three carbons anchor it far more weakly than cypionate's eight, so the depot drains in days instead of weeks. Esterases clip the tail off; only the freed testosterone binds the receptor. The short tail also carries less dead weight: testosterone is 288 g/mol, propionate 344 and cypionate 413, so about 84 percent of each milligram of propionate is hormone against roughly 70 percent for cypionate.
3. Filling the vial. The ester is dissolved in a carrier oil, commonly sesame or grapeseed, with benzyl alcohol as a preservative and benzyl benzoate to hold it in solution; propionate needs less co-solvent than heavier esters. The solution is sterile-filtered and filled; under GMP rules every batch is tested for identity, potency, sterility, and endotoxins. The chemistry is old and undramatic. What varies outside regulated manufacturing is the sterile fill, the solvent ratio, and whether anyone tested the batch at all.
Worth knowing
The anabolic-to-androgenic ratios quoted for other steroids trace back to a 1953 castrated-rat assay in which the comparison injection was testosterone propionate. That is why testosterone is listed at 1:1 in those tables: it is the yardstick, in propionate form, and every ratio above or below it is a ratio to this ester.
Hershberger LG, Shipley EG, Meyer RK. Myotrophic activity of 19-nortestosterone and other steroids determined by modified levator ani muscle method.Proceedings of the Society for Experimental Biology and Medicine 83(1):175-180, 1953
Propionate is the reason the other esters exist. It was the first injectable testosterone sold as a drug, and the search for something that did not need injecting two or three times a week is what produced enanthate and cypionate in the 1950s.
Nieschlag E, Nieschlag S. The history of discovery, synthesis and development of testosterone for clinical use.European Journal of Endocrinology 180(6):R201-R212, 2019
Written and reviewed by Evan Marlow, developer of DosePlot · Updated 2026-08-27
Not medical advice. DosePlot is an informational tool, not a healthcare provider, and using it creates no provider-patient relationship. Do not start, stop, or change any protocol without the approval of a licensed healthcare professional.
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