From the Guidelines
Yes, testosterone cypionate can be dosed weekly, with a typical dose range of 50-200 mg administered as an intramuscular injection. According to the study by 1, testosterone cypionate can be dosed at 100-200 mg every 2 weeks or 50 mg weekly. This dosing schedule is common in testosterone replacement therapy (TRT) for men with hypogonadism.
Key Considerations
- The injection is typically given in the gluteal muscle (buttock), thigh, or sometimes the deltoid (shoulder) [ 1 ].
- It's essential to rotate injection sites to prevent tissue damage.
- Some patients may experience post-injection pain, so using proper injection technique is crucial.
- Regular blood monitoring is necessary to ensure testosterone levels remain within the appropriate therapeutic range and to watch for potential side effects.
Dosing and Administration
- Weekly injections help maintain more stable testosterone levels compared to less frequent dosing, which can reduce the mood swings and energy fluctuations some patients experience [ 1 ].
- When beginning treatment, your healthcare provider might start with a lower dose and adjust based on your blood test results and symptom response.
- While weekly dosing is common, some providers may recommend splitting the dose into twice-weekly injections for even more stable hormone levels.
From the FDA Drug Label
Testosterone esters in oil injected intramuscularly are absorbed slowly from the lipid phase; thus, testosterone cypionate can be given at intervals of two to four weeks
Testosterone cypionate cannot be dosed weekly, as the recommended interval is two to four weeks. This is due to its slow absorption from the lipid phase when injected intramuscularly, with a half-life of approximately eight days 2.
From the Research
Testosterone Cypionate Dosing
- Testosterone cypionate can be dosed weekly, as evidenced by a study published in the Journal of the Endocrine Society 3, which found that serum testosterone concentrations remained stable between injections in patients receiving subcutaneous testosterone cypionate weekly.
- Another study published in Fertility and Sterility 4 found that testosterone cypionate injections every 14 days did not maintain increased testosterone concentrations for 2 full weeks, suggesting that weekly dosing may be more effective.
- A comparison of outcomes for hypogonadal men treated with intramuscular testosterone cypionate versus subcutaneous testosterone enanthate found that both groups had significant increases in trough testosterone levels when dosed weekly 5.
- However, it is worth noting that weekly dosing of testosterone cypionate may be associated with a higher risk of polycythaemia, as found in a retrospective cross-sectional analysis of transmasculine individuals 6.
- A review of the literature on erythrocytosis and polycythemia secondary to testosterone replacement therapy found that all testosterone replacement therapy formulations, including injectables like testosterone cypionate, can cause increases in hemoglobin and hematocrit, but the risk of veno-thrombotic events remains inconclusive 7.
Administration Routes
- Testosterone cypionate can be administered via intramuscular (IM) or subcutaneous (SC) injection, with SC injection being a relatively painless and easy to self-administer option 3.
- A comparison of IM testosterone cypionate and SC testosterone enanthate found that both routes were effective in increasing testosterone levels, but SC testosterone enanthate was associated with lower levels of post-therapy hematocrit and estradiol 5.
Monitoring and Safety
- Regular monitoring of hematocrit is important for individuals treated with testosterone cypionate, particularly those at risk for polycythaemia 6.
- The risk of veno-thrombotic events associated with testosterone replacement therapy, including testosterone cypionate, remains inconclusive, and further trials are needed to fully evaluate the hematological side effects associated with testosterone replacement therapy 7.