Short answer: Testopel is testosterone in 75 mg pellets implanted under the skin, 150 mg to 450 mg every 3 to 6 months.1 Testosterone cypionate (Depo-Testosterone) is 50 to 400 mg injected deep into the buttock muscle every 2 to 4 weeks.2 Both are approved for low testosterone from primary or hypogonadotropic hypogonadism, and neither has a boxed warning. Neither label reports a trial against the other.
| Testopel (pellets) | Testosterone cypionate (Depo-Testosterone) | |
|---|---|---|
| Form | 75 mg pellets implanted under the skin1 | Oil injection into the gluteal muscle2 |
| Dose and timing | 150 mg to 450 mg every 3 to 6 months1 | 50 to 400 mg every 2 to 4 weeks2 |
| How long a dose lasts | Usually 3 to 4 months, sometimes 61 | Given again every 2 to 4 weeks2 |
| Approved for | Low testosterone from primary or hypogonadotropic hypogonadism; delayed puberty in selected boys1 | Low testosterone from primary or hypogonadotropic hypogonadism2 |
| Changing the dose | Much less flexible than oral or injected testosterone1 | Adjusted by response and side effects2 |
| Side effects listed | Implant site infection, pellets pushing out, acne, breast enlargement, more red blood cells; no percentages1 | Acne, breast enlargement, more red blood cells, injection site pain; no percentages2 |
| Boxed warning | None1 | None2 |
How often a dose is given and how easy it is to change. Testopel pellets release testosterone over months: the label says about one-third is absorbed in the first month, one-fourth in the second and one-sixth in the third, and the effect usually lasts three to four months.1 The label also says pellets are much less flexible for dose changes than oral or injected testosterone, so the amount is estimated with great care.1 Cypionate is injected every 2 to 4 weeks, and the dose is adjusted by response and side effects.2
The two labels list much the same warnings: blood clots, blood pressure, heart risk, liver tumors with long high-dose use, and abuse.12 Testopel adds implant site problems such as infection and pellets pushing out of the skin.1 Both labels say safety and effectiveness in men with age-related low testosterone have not been established.12
Which form fits is for your prescriber. More detail: Testopel side effects, Depo-Testosterone side effects, the Testopel and Depo-Testosterone dosing schedules, and the Testosterone Cypionate guide.