What is the starting dose of injectable testosterone (testosterone cypionate or testosterone enanthate) for a patient with hypogonadism (low testosterone)?

Starting Dose of Injectable Testosterone for Hypogonadism

The recommended starting dose of injectable testosterone for patients with hypogonadism is 50 to 200 mg of testosterone cypionate or enanthate every 2 weeks, with 100-200 mg every 2 weeks being the most effective regimen for most patients. 1, 2, 3

Dosing Recommendations

• The FDA-approved dosage range for testosterone cypionate injection for hypogonadal males is 50 to 400 mg administered every two to four weeks 3
• Clinical guidelines recommend 100-200 mg every 2 weeks as the most effective dosing regimen for testosterone cypionate, which effectively suppresses elevated LH and FSH levels while maintaining serum testosterone within physiologic levels 1
• Alternative dosing options include 50 mg weekly, which may provide more stable testosterone levels with fewer fluctuations 2
• Lower frequency dosing (every 2 weeks) may lead to greater peaks and valleys in testosterone levels compared to weekly administration 2

Target Levels and Monitoring

• The goal of therapy is to achieve testosterone levels in the mid-normal range (450-600 ng/dL) 1, 4
• Testosterone levels should be measured 2-3 months after treatment initiation and after any dose adjustment 2
• For patients on every-2-week dosing, levels should be measured midway between injections 2
• Once stable levels are confirmed, monitoring every 6-12 months is typically sufficient 2
• Regular monitoring should include:
  • Hematocrit/hemoglobin (risk of erythrocytosis) 1
  • Prostate-specific antigen (PSA) 1
  • Digital rectal examination 1

Clinical Considerations

• Diagnosis of hypogonadism requires both low testosterone levels (<300 ng/dL) and symptoms/signs of testosterone deficiency 1
• Diagnosis should be confirmed with a second morning total testosterone measurement before initiating treatment 1, 2
• Injectable testosterone formulations may cause greater fluctuations in serum testosterone levels compared to transdermal preparations 1
• The 100 mg and 200 mg regimens have been shown to effectively suppress elevated serum FSH concentrations to normal range 5

Safety Considerations and Potential Pitfalls

• Injectable testosterone may be associated with a greater risk of cardiovascular events compared to gels, possibly due to increased time spent in both supratherapeutic and subtherapeutic ranges 1, 2
• Testosterone therapy is contraindicated in men seeking fertility 1
• Active or treated male breast cancer remains an absolute contraindication for testosterone therapy 1
• Testosterone therapy should be avoided in patients with recent cardiovascular events (within past 3-6 months) 1
• Intramuscular testosterone cypionate (IM-TC) is associated with higher post-therapy estradiol and hematocrit levels compared to subcutaneous administration 6
• If hematocrit rises above the reference range, consider temporarily withholding therapy, reducing the dose, or performing phlebotomy 1

Administration Considerations

• Testosterone cypionate injection is for intramuscular use only and should be given deep in the gluteal muscle 3
• Subcutaneous administration is an emerging alternative that may provide more stable testosterone levels with less discomfort than intramuscular injections 7, 6
• Warming and shaking the vial should redissolve any crystals that may have formed during storage at temperatures lower than recommended 3