Testosterone cypionate is a prescription injectable form of testosterone used as testosterone replacement therapy for males with medically confirmed testosterone deficiency. It is testosterone attached to cypionate, an ester that helps the oil-based injection release gradually after administration. This allows dosing at intervals instead of every day.
Testosterone Cypionate at a Glance
| Attribute | Details |
|---|---|
| Drug type | Androgen, or testosterone replacement medicine |
| Form | Oil-based injection |
| Usual route | Deep intramuscular injection |
| U.S. prescription status | Schedule III controlled substance |
| Main labeled use | Testosterone deficiency caused by certain medical conditions |
| Common labeled strengths | 100 mg/mL and 200 mg/mL |
| Approximate half-life | About 8 days after intramuscular injection |
| Common brand association | Depo-Testosterone |
Strengths and administration instructions can differ between manufacturers. Follow the prescription label supplied with the medication.
How Does Testosterone Cypionate Work?
Testosterone cypionate works by releasing testosterone slowly from the injection site. The cypionate ester makes testosterone less water-soluble, so the oil-based medication is absorbed gradually from muscle tissue. After release, testosterone activates androgen receptors and supports functions that depend on testosterone.
When testosterone deficiency is present, treatment may help improve effects linked to low testosterone, including reduced libido, low energy, loss of muscle mass and impaired development.
What Is Testosterone Cypionate Used For?
Testosterone cypionate is used as replacement therapy for males whose bodies do not produce enough testosterone because of a medical condition. The U.S. prescribing information lists conditions such as:
- Primary hypogonadism, where the testes cannot produce enough testosterone
- Hypogonadotropic hypogonadism, where problems involving the pituitary gland or hypothalamus reduce testosterone production
- Certain congenital, surgical, traumatic, inflammatory or treatment-related conditions that affect testosterone production
Symptoms alone are not enough to establish the diagnosis. The prescribing information recommends confirming low testosterone with morning blood tests taken on at least two separate days. The label also states that safety and effectiveness have not been established when testosterone deficiency is attributed only to aging.
How Is Testosterone Cypionate Administered?
Testosterone cypionate is given by deep intramuscular injection, generally into the gluteal muscle. It should not be injected into a vein.
The dose and interval depend on the diagnosis, treatment response, age and adverse effects. The product label lists a replacement range of 50 to 400 mg every two to four weeks. That range is not an individualized dosing recommendation.
Some people experience a rise and fall in testosterone levels between injections. A clinician may change the dose or timing based on symptoms, testosterone results and safety monitoring.
What Are the Main Risks and Side Effects?
The main risks associated with testosterone cypionate include:
- Increased red blood cell production, or polycythemia
- Increased blood pressure
- Acne and oily skin
- Gynecomastia, meaning breast tissue enlargement
- Fluid retention and swelling
- Pain or inflammation at the injection site
- Reduced sperm production
- Worsening symptoms of benign prostate enlargement
- Venous blood clots, including deep vein thrombosis and pulmonary embolism
The product label states that evidence about major cardiovascular events, including heart attack and stroke, is inconclusive. It also warns that testosterone can increase blood pressure, which may raise cardiovascular risk over time.
Treatment may involve monitoring testosterone levels, blood pressure, hematocrit, prostate-related measures and other laboratory results. People with prostate cancer, male breast cancer, uncontrolled hypertension, serious heart, liver or kidney disease, or certain other conditions may not be appropriate candidates. Testosterone is contraindicated during pregnancy because it can harm or masculinize a developing female fetus.
Is Testosterone Cypionate a Steroid?
Yes. Testosterone cypionate is an anabolic-androgenic steroid, but it is also a prescription hormone medication. In medically supervised treatment, it replaces testosterone that the body does not produce adequately. Using it at high doses for muscle gain, bodybuilding or athletic performance is different from testosterone replacement therapy.
The FDA-approved product information states that testosterone cypionate has not been shown to be safe or effective for enhancing athletic performance. Misuse or high-dose use can cause serious cardiovascular, psychiatric, hormonal and reproductive problems.
Bottom Line
Testosterone cypionate is intended for confirmed testosterone deficiency caused by specific medical conditions. It should be used under an individualized prescription with follow-up for blood pressure, blood changes, fertility effects and other complications.