From the Guidelines
Testosterone pellets do not produce more stable testosterone levels or decrease the risk of erythrocytosis compared to other testosterone replacement therapy (TRT) methods. In fact, testosterone pellets typically provide higher peak levels of testosterone and can actually increase the risk of erythrocytosis (elevated red blood cell count) due to their sustained release pattern 1. Testosterone pellets are subcutaneous implants that release testosterone over 3-6 months, providing convenience but making dose adjustments difficult if side effects occur. Other TRT options like injections (typically testosterone cypionate 50-100mg weekly or testosterone enanthate 100-200mg every 2 weeks), topical gels (AndroGel, Testim 50-100mg daily), or patches may offer better control over hormone levels.
Key Considerations
- All forms of TRT require regular monitoring of hematocrit and hemoglobin levels to watch for erythrocytosis, which occurs in approximately 20-30% of men on TRT 1.
- Injections appear to be associated with a greater risk of erythrocytosis than topical preparations, with studies showing that 15.4 percent and 43.8 percent of patients had at least one documented elevated hematocrit value during the course of the study 1.
- If erythrocytosis develops, dose reduction, switching to another TRT method, or therapeutic phlebotomy may be necessary to manage this side effect.
Treatment Options
- Testosterone pellets (Testopel): 150-450 mg every 3-6 mo, subcutaneous implant under skin in the hips 1.
- Injections: testosterone cypionate 50-100mg weekly or testosterone enanthate 100-200mg every 2 weeks 1.
- Topical gels: AndroGel, Testim 50-100mg daily 1.
- Patches: testosterone 24-h patch (Androderm) 2-6 mg/d 1.
From the Research
Testosterone Pellets and Erythrocytosis
- The use of testosterone pellets for testosterone replacement therapy (TRT) has been associated with an increased risk of erythrocytosis, which is characterized by an elevated hematocrit level 2.
- A study published in the Journal of Andrology found that only one patient developed erythrocytosis out of 273 patients treated with subcutaneous testosterone pellets 3.
- However, another study published in the Asian Journal of Andrology reported a higher incidence of secondary polycythemia in men treated with subcutaneously implanted testosterone pellets, with an estimated rate of 10.4% at 6 months, 17.3% at 12 months, and 30.2% at 24 months 4.
- The management of erythrocytosis in men receiving testosterone therapy is crucial, and providers should decrease or discontinue therapy if the patient's hematocrit exceeds 54% until the hematocrit normalizes 5.
Testosterone Levels and Pellet Therapy
- Testosterone pellet therapy has been shown to increase total testosterone levels into the therapeutic range at 1 month postimplantation and sustain therapeutic levels for 4-6 months 6.
- Higher pellet numbers (10-12 pellets) have been associated with higher, more consistent, and longer maintenance of testosterone levels within the therapeutic range 3, 6.
- The optimal dosing and frequency of reimplantation of testosterone pellets remain incompletely elucidated parameters, and further studies are needed to fully evaluate the effects of pellet therapy on testosterone levels and erythrocytosis 3.