Testosterone Cypionate Dosing for Intramuscular Testosterone Replacement Therapy
The recommended dose of testosterone cypionate is 100-200 mg administered intramuscularly every 2 weeks, or alternatively 50-100 mg weekly, with the FDA-approved range being 50-400 mg every 2-4 weeks depending on individual patient response. 1
Standard Dosing Regimens
Biweekly Administration
- 100-200 mg intramuscularly every 2 weeks is the most commonly cited dosing range 2
- Available in 100 mg/mL and 200 mg/mL concentrations 2
- Administered deep in the gluteal muscle for injections by healthcare providers, or in the thighs for self-injection 2
Weekly Administration
- 50-100 mg intramuscularly weekly represents an alternative dosing schedule 2
- Weekly dosing may reduce the fluctuations in serum testosterone levels that occur with biweekly injections 2
Dose Titration and Monitoring
Initial Follow-up
- Measure testosterone levels 2-3 months after treatment initiation or after any dose change 2
- For patients receiving injections, measure levels midway between injections, targeting a mid-normal value of 500-600 ng/dL 2
- Once stable levels are confirmed, monitoring every 6-12 months is sufficient 2
Dose Adjustment Strategy
- If clinical response is suboptimal and testosterone levels remain in the low-normal range, increase the dose 2
- If adequate clinical response is achieved, no dosage adjustment is needed even if levels are in the low-normal range 2
- Peak serum testosterone levels occur 2-5 days after injection, with levels often returning to baseline by 10-14 days 2
Important Clinical Considerations
Advantages of Injectable Testosterone
- Relatively inexpensive compared to transdermal preparations 2
- Flexible and infrequent dosing reduces administration burden 2
- No risk of transference to partners or children, unlike topical preparations 2
Key Disadvantages and Safety Concerns
- Fluctuating serum testosterone levels with peaks and valleys is the primary limitation 2
- Some evidence suggests injections may be associated with greater cardiovascular risk compared to gels, potentially related to time spent in supratherapeutic and subtherapeutic ranges 2
- However, these cardiovascular concerns may be related to high-risk patient populations studied rather than the formulation itself 2
Monitoring for Adverse Effects
- Hematocrit elevation is a significant concern; men receiving 200 mg biweekly have higher risk of hematocrit rising above 54% compared to 100 mg weekly (8% vs 1%) 3
- If hematocrit rises above the reference range, consider temporarily withholding therapy, reducing dosage, or performing phlebotomy 2
- Weekly 100 mg dosing appears safer than biweekly 200 mg dosing regarding erythrocytosis risk 3
Alternative Dosing Considerations
Lower Peak-to-Trough Ratio
- Weekly injections of 100 mg produce more stable testosterone levels and lower rates of adverse effects compared to 200 mg every 2 weeks 3
- The higher average serum testosterone over the dosing interval with 200 mg biweekly is associated with increased risk of erythrocytosis 3
Subcutaneous Alternative
- Subcutaneous testosterone cypionate or enanthate 50-150 mg weekly (median 75-80 mg) is an effective alternative that patients markedly prefer over intramuscular injections 4, 5
- Subcutaneous administration is associated with lower post-therapy estradiol and hematocrit levels compared to intramuscular administration 5