Recommended Biweekly Dose of Testosterone Cypionate
For testosterone replacement therapy in adult males with confirmed hypogonadism, the recommended biweekly dose of testosterone cypionate is 100-200 mg administered intramuscularly every 2 weeks. 1, 2
Standard Dosing Guidelines
The FDA-approved dosing range for testosterone cypionate is 50-400 mg every 2-4 weeks, with the most common regimen being 100-200 mg every 2 weeks. 1, 2 The American College of Gastroenterology specifically recommends starting at 100-200 mg every 2 weeks or 50-100 mg weekly for testosterone enanthate or cypionate. 1
Dosing Frequency Considerations
- Weekly dosing of 50-100 mg provides more stable testosterone levels compared to biweekly administration, which is increasingly preferred to minimize fluctuations. 1
- Peak serum testosterone levels occur 2-5 days after injection, with levels often returning to baseline by 10-14 days post-injection. 1, 3
- The biweekly 100-200 mg regimen creates significant peak-to-trough variation, spending considerable time in both supraphysiologic and subtherapeutic ranges. 1
Monitoring Requirements
Testosterone levels should be measured 2-3 months after treatment initiation or any dose change, drawn midway between injections (days 5-7), targeting mid-normal values of 450-600 ng/dL. 1, 3 Once stable levels are achieved, monitoring should occur every 6-12 months. 1
Critical Safety Monitoring
- Hematocrit/hemoglobin must be monitored at each visit, as injectable testosterone causes erythrocytosis in approximately 43.8% of patients. 1 Treatment should be withheld if hematocrit exceeds 54%. 1
- PSA and digital rectal examination should be performed in men over 40 years. 1
- Injectable testosterone carries greater cardiovascular risk compared to transdermal preparations, possibly due to fluctuating testosterone levels. 1
Dose Adjustment Algorithm
If testosterone levels are below target (450-600 ng/dL) at midpoint testing and symptoms persist, increase the dose incrementally. 1 If levels exceed 1000 ng/dL, reduce the dose by approximately 50%. 1
When to Consider Weekly Dosing Instead
Patients experiencing significant mood or energy fluctuations between injections should be switched from biweekly 100-200 mg to weekly 50-100 mg dosing, as this provides more stable day-to-day testosterone levels and reduces the risk of erythrocytosis. 1 Weekly dosing is particularly important for patients with cardiovascular risk factors or those who develop hematocrit elevations on biweekly dosing. 1
Common Pitfalls to Avoid
- Do not measure testosterone levels at peak (days 2-5) or trough (days 13-14), as this will lead to inappropriate dose adjustments. 1 Always measure midway between injections (days 5-7). 1
- Do not continue biweekly dosing if the patient develops erythrocytosis (hematocrit >52%), as this significantly increases thrombotic risk. 1 Switch to weekly dosing or transdermal formulations. 1
- Do not use testosterone therapy in men actively seeking fertility, as it causes azoospermia; gonadotropin therapy (hCG plus FSH) is mandatory instead. 1, 3
Alternative Formulation Considerations
If erythrocytosis develops on injectable testosterone (hematocrit 52-54%), switch to transdermal testosterone gel, which has a markedly lower erythrocytosis rate of 15.4% compared to 43.8% with injectables. 1 Transdermal formulations provide more stable testosterone levels and may be preferred as first-line therapy in elderly patients or those with cardiovascular disease. 1