Testosterone cypionate (often sold under brand names such as Depo‑Testosterone®, Testosterone Cypionate, etc.) is a prescription‑only, injectable anabolic–androgenic steroid (AAS) used mainly to treat low testosterone (hypogonadism) and to replace testosterone in men who cannot produce enough on their own. It may also be used in some hormone‑replacement regimens for transgender men, but it is not a supplement and should only be taken under medical supervision.
What it is
| Feature |
Details |
| Chemical form |
Testosterone esterified with cyclopentyl‑3‑methoxy‑propionate (cypionate), which slows absorption after intramuscular injection. |
| Pharmacokinetics |
Peak serum levels 3–7 days after injection; half‑life ≈ 8 days (variable). Allows dosing every 1–4 weeks. |
| Legal status |
Schedule III controlled substance in the United States; prescription‑only in most countries. |
Indications (approved uses)
- Male hypogonadism – low testosterone levels that cause symptoms such as fatigue, loss of libido, decreased muscle mass, depression, and impaired cognition.
- Delayed puberty in boys (rarely).
- Hormone replacement therapy for transgender men (under endocrinology guidance).
- Certain endocrine disorders where testosterone supplementation is medically justified.
Note: The drug is not approved for bodybuilding, athletic performance enhancement, or “just to look more muscular.” Misuse can lead to serious health problems.
Typical dosing (for hypogonadism)
| Route |
Dose |
Frequency |
| Intramuscular injection |
50 mg, 100 mg, or 250 mg (depending on formulation) |
Every 1–4 weeks (usually 1 mg/kg body‑weight per week equivalent) |
The exact dose and interval are determined by a physician based on blood testosterone levels, symptoms, and tolerance.
Common side effects
| Category |
Example Symptoms |
| Hormonal |
Acne, oily skin, breast enlargement (gynecomastia), increased body hair, voice deepening, loss of female pattern baldness |
| Metabolic |
Fluid retention, high blood pressure, altered lipid profile (↑LDL/↓HDL), increased hematocrit |
| Psychiatric |
Mood swings, irritability, aggression, anxiety |
| Reproductive |
Suppression of spermatogenesis (infertility) |
| Others |
Injection site pain, bruising, local tissue irritation |
Severe but uncommon: cardiac events, liver dysfunction, prostate growth.
Contraindications
- Active prostate or breast cancer (or unexplained testicular lump).
- Known or suspected estrogen‑dependent breast disease.
- Untreated severe hepatic disease.
- Hypertension or uncontrolled cardiovascular disease (increased risk of heart attack/stroke).
- Pregnancy (highly teratogenic).
Drug interactions
| Drug |
Interaction |
| Estrogens (oral contraceptives, hormone replacement) |
May counteract androgen effects and increase breast tissue stimulation. |
| Anti‑androgens (spironolactone, flutamide) |
Reduce testosterone action, may blunt benefits. |
| Statins |
Some evidence of improved lipid profiles; monitor for myopathy. |
| Certain antibiotics (e.g., fluoroquinolones) |
May slightly increase testosterone metabolism. |
Always inform your prescriber of all medications, supplements, and herbal products.
Monitoring
- Baseline labs: total testosterone, free testosterone, LH/FSH, PSA, liver function tests, lipid panel, CBC.
- Follow‑up: every 3–6 months while on therapy; adjust dose based on symptoms and testosterone levels.
- PSA: monitor for prostate health, especially in men >50 years.
Storage & Handling
- Store at room temperature (15–25 °C, 59–77 °F).
- Protect from extreme heat, cold, and direct sunlight.
- Keep in a tight‑sealed vial; do not freeze.
- After reconstitution (if needed), inject promptly; do not store the reconstituted solution for long periods.
Legal & Safety Tips
- Prescription‑only: Never purchase testosterone from unverified online vendors; counterfeit products are common and dangerous.
- Avoid “performance‑enhancement” use: The risks outweigh any potential benefit, and it is illegal in most jurisdictions.
- Report any adverse effects to your healthcare provider.
- Do not share the medication with family or friends.
Bottom line
Testosterone cypionate is a powerful, prescription‑only treatment for low testosterone. When used as directed under a qualified clinician’s supervision, it can improve quality of life in hypogonadal men and support gender‑affirming therapy. Misuse carries significant health risks, including cardiovascular complications, hormonal disturbances, and legal consequences. If you have specific questions about your therapy, side effects, or dosing, discuss them with your prescribing doctor or pharmacist.