Testosterone Propionate
Also known as: Test P
A short-acting injectable testosterone ester requiring more frequent dosing. Less common for maintenance TRT. Prescription medication.
Last updated
Mechanism of Action
A short-ester testosterone released quickly after injection and cleaved to free testosterone acting at the androgen receptor. The short propionate ester means a much shorter half-life, so more frequent (e.g. every-other-day) injections are needed to maintain stable levels.
- Half-life
- ~0.8 days (propionate ester)
- Administration Routes
- Intramuscular, Subcutaneous
- Research Status
- Clinical
Reported Benefits
- Rapid onset and rapid clearance (fine-grained control)
- Lower injection-site depot than long esters
- Same androgenic replacement effects as other esters
Potential Side Effects
- More frequent injections required
- Injection-site irritation (higher concentration esters)
- Erythrocytosis, estrogenic effects, testicular atrophy — as with all testosterone
Common Dosing
Because of the short ester, protocols use smaller, more frequent injections (often every other day). Total weekly exposure and titration are set by a prescribing clinician.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Prostate or breast cancer
- Untreated erythrocytosis
- Pregnancy
- Uncontrolled cardiovascular disease — medical supervision required
HCG (Human Chorionic Gonadotropin)
A glycoprotein hormone produced in pregnancy that mimics luteinizing hormone, used clinically to stimulate gonadal function. It is studied to support testosterone production and fertility.
Anastrozole
An aromatase inhibitor used off-label to control estrogen elevation on testosterone therapy. Prescription medication (approved for breast cancer).
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Pharmacokinetic properties of testosterone propionate in normal men
1986
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Pharmacokinetic studies of testosterone propionate using gas chromatography/mass spectrometry/selected ion monitoring
1988
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Frequent serum sampling in healthy men discloses testosterone peaks exacerbated by testosterone propionate administration
1997