What testosterone cypionate is
Testosterone cypionate is testosterone with a cypionate ester attached, dissolved in oil so it can be injected and released slowly. It is sold as Depo-Testosterone and as several generics, and it is one of the most familiar testosterone injections in the United States.
The Depo-Testosterone label spells out the basics. It comes in 100 and 200 mg per mL strengths, in cottonseed oil with benzyl benzoate and a benzyl alcohol preservative. Testosterone is a Schedule III controlled substance, which means each refill is tracked and the medicine must come from a licensed source.
FDA status and the 2025 label update
As of October 2026, testosterone cypionate is FDA-approved for testosterone replacement in men with primary hypogonadism (a testicular problem) or hypogonadotropic hypogonadism (a pituitary or brain signaling problem). The label notes that safety and effectiveness have not been established for low testosterone due to aging alone, so that use is a judgment call made case by case.
In 2025 the FDA required class-wide labeling changes for testosterone products after the TRAVERSE heart-safety trial. Labels now warn that testosterone can increase blood pressure, and earlier language suggesting a higher risk of heart attack and stroke was removed. Our article on the 2025 FDA testosterone label changes explains what changed and why.
How does it work in the body?
After an injection, the oil forms a small depot in the muscle. Testosterone cypionate seeps out slowly, enzymes strip off the ester, and free testosterone enters the blood. The label puts the half-life at approximately eight days, which is why a single shot can cover a week or more.
That slow release still produces a curve. Levels climb for a day or two after the shot, peak, and then fall until the next dose. The label’s range for men with hypogonadism is 50 to 400 mg every two to four weeks, shown here as context only: your provider sets the amount and the interval, and you never adjust it on your own.
Why splitting the weekly dose smooths the peaks
Longer gaps between larger doses mean higher peaks and deeper troughs. Splitting the same total into smaller, more frequent injections narrows that swing.
| Schedule (same total dose) | Peak | Trough | Possible pattern |
|---|---|---|---|
| Every 2 weeks | Highest | Lowest | Can feel strong early, with energy or libido fading before the next shot |
| Weekly | Moderate | Moderate | Steadier, sometimes with a mild dip late in the week |
| Twice weekly | Lowest | Highest | Most even levels, at the cost of more injections |
Smoother levels can matter for more than mood. Testosterone peaks drive estradiol and red blood cell production, so trimming them may make it easier to keep hematocrit and estradiol in range. Our answer on weekly or twice-weekly testosterone injections compares the trade-offs, and testosterone cypionate versus enanthate covers the sister ester, also profiled on our testosterone enanthate page.
Side effects and who should not use it
Common effects include acne or oily skin, soreness at the injection site, fluid retention, breast tenderness, and a rise in red blood cell count. MedlinePlus lists which effects need a prompt call. Testosterone also shrinks the testes and lowers sperm production, because it switches off the brain’s signals to make your own.
The label warns about blood pressure increases, blood clots in the legs and lungs, worsening urinary symptoms in men with an enlarged prostate, and abuse at high doses. Testosterone cypionate is not used in men with known or suspected prostate or breast cancer, or in anyone allergic to its ingredients, including cottonseed oil. The AUA guideline states that testosterone should not be given to men who are currently trying to conceive. Extra caution applies with a high hematocrit, untreated severe sleep apnea or poorly controlled heart failure.
Call 911 for chest pain, sudden shortness of breath, one-sided weakness or trouble speaking, or a swollen, painful calf. Those are not reasons to wait for your next visit.
Monitoring on testosterone cypionate
Good monitoring is what makes injectable testosterone safe over years. The Endocrine Society guideline and the AUA guideline line up on the core checks:
- Hematocrit. Measured before starting and then periodically, because testosterone raises red cell mass. See hematocrit for men.
- PSA. Measured before starting in men over 40 and rechecked on treatment.
- Testosterone level. The AUA defines success as a level of 450 to 600 ng/dL, the middle of the normal range, drawn at a consistent point in the injection cycle. Our page on trough versus peak labs on TRT explains the timing.
- Estradiol. Checked when symptoms such as breast tenderness appear. Adding an estrogen blocker is rarely the first fix; see anastrozole on TRT.
- Blood pressure, now a labeled warning for every testosterone product.
How Ultimate Male uses injectable testosterone
Injectable testosterone is one of the core TRT options at Ultimate Male, given on a set schedule in the clinic or at home. Your provider confirms which ester your plan uses, the dose, the interval and whether injections go into muscle or under the skin, and shows you the technique at the first visit. Our testosterone injections page covers the in-clinic and at-home options.
Every plan starts with the TRT pre-screening panel (total testosterone, estradiol, PSA and a complete blood count), drawn on site in San Gabriel or Downey with results in 24 to 48 hours, then a one-on-one consultation with a PA-C or MD. A consultation is an evaluation, not a promise of treatment. To begin, read about testosterone therapy at Ultimate Male or call 626-319-5261 for a free 10-minute phone call.
