Testosterone pellets are small cylinders of crystalline testosterone, about the size of a grain of rice, implanted subcutaneously, typically in the upper buttock or hip area, under local anesthesia. Once in place, they slowly release testosterone over 3-6 months, after which they dissolve completely. A new set of pellets is then implanted. This delivery method eliminates the need for weekly injections or daily gel application at the cost of an in-office procedure every few months.

Pellet therapy is FDA-regulated but the specific pellets themselves are compounded, they are not an FDA-approved drug product in the way that injectable testosterone or branded gels are.

How Pellets Release Testosterone

Crystalline testosterone pellets dissolve by a process of diffusion, testosterone molecules migrate out of the pellet surface in contact with tissue fluid, at a rate roughly proportional to physical activity. Higher activity increases blood flow and pellet surface dissolution rate, producing higher testosterone levels during active periods and lower levels at rest. This mirrors the body’s natural testosterone rhythm more closely than weekly injections, which produce a large peak followed by a steady decline.

The typical pellet implant provides 3-6 months of testosterone release. The duration depends on the number and size of pellets implanted, which is calculated based on baseline testosterone levels, body weight, and the target range.

Efficacy Evidence

The evidence base for pellet therapy is smaller than for injectable and gel TRT because the pellets are compounded products rather than FDA-approved drugs, which limits industry-funded trials.

Available evidence, primarily from retrospective analyses and smaller prospective studies, shows that pellets effectively raise testosterone into the therapeutic range in most men. A 2016 review in Sexual Medicine Reviews examined existing data on pellet therapy and found testosterone levels in the normal range in most patients, with patient-reported improvements in libido, energy, and mood comparable to other TRT modalities.

However, the evidence does not clearly establish superiority of pellets over injections or gels for clinical outcomes in men with hypogonadism. The delivery method is a practical and patient preference issue as much as a clinical one.

Side Effects and Complications

Extrusion: In approximately 1-5% of implants, the pellet migrates toward the surface and extrudes through the skin. This is more common in patients who are very active immediately after implantation, which is why a period of reduced intense exercise is typically recommended for 1-2 weeks after the procedure.

Infection: As with any subcutaneous procedure, there is a small infection risk at the implant site (typically under 1%).

Dose inflexibility: Once pellets are in place, the dose cannot be adjusted without removing them, which requires another procedure. If testosterone levels run too high or side effects develop, the only option is waiting for pellets to dissolve over weeks to months, or surgical removal.

Erythrocytosis: Pellets raise hematocrit like all TRT forms. Monitoring is required.

Estrogen Management Concerns

Pellets dissolve faster with physical activity. Men who exercise heavily can have higher testosterone peaks post-exercise, which increases aromatization and can elevate estradiol. Some providers add anastrozole pellets alongside testosterone pellets to manage estrogen. The evidence for routine anastrozole use with TRT, and specifically with pellets, is not strong, and the potential for driving estradiol too low exists.

Cost

Pellet implantation involves a procedure fee that significantly increases the cost compared to other TRT modalities. Typical all-in cost for a pellet session ranges from $500 to $1,000, which covers the pellets and the implantation procedure. With 2-4 sessions per year required, annual cost of $1,000-4,000 is common, substantially higher than injectable testosterone.

Some health insurance policies cover testosterone pellets; many do not, particularly given their compounded status.

Who Chooses Pellets

Patient preference is the primary driver. Men who choose pellets often:

  • Strongly prefer to avoid self-injection
  • Find daily gel application inconvenient
  • Value the set-and-forget nature of a 3-6 month release cycle
  • Accept the cost premium for reduced administration burden

For patients for whom the cost premium and procedure requirement are acceptable, pellets produce clinical outcomes similar to injections and gels. For those who are cost-sensitive or prefer more dose flexibility, injections remain the most economical option.

For the comparison between the two most widely used TRT methods, see Testosterone Injections vs. Gel: Which Delivery Method Is Better?.