What is the starting dose of injectable testosterone (testosterone) for a patient with secondary hypogonadism and low testosterone?

Starting Dose of Injectable Testosterone for Secondary Hypogonadism

For patients with secondary hypogonadism and low testosterone, the recommended starting dose is 50-200 mg of testosterone cypionate administered intramuscularly every 2 weeks, or 50 mg weekly. 1

Dosing Options and Administration

• The FDA-approved dosage for testosterone cypionate in hypogonadal males is 50-400 mg intramuscularly every 2-4 weeks 1
• More frequent administration (weekly vs. biweekly) provides more stable testosterone levels with fewer fluctuations 2
• Testosterone cypionate should be injected deeply into the gluteal muscle, alternating between left and right buttock for consecutive injections 1
• Lower starting doses (50-100 mg weekly) may be preferred to minimize side effects while assessing individual response 2, 3

Monitoring Protocol

• Testosterone levels should be measured 2-3 months after treatment initiation or after any dose adjustment 4, 2
• For accurate assessment, measure testosterone levels midway between injections, targeting mid-normal values (500-600 ng/dL) 4, 2
• The first follow-up visit should occur at 1-2 months to assess clinical efficacy and consider dose adjustments if needed 4
• Once stable levels are achieved, monitoring every 6-12 months is typically sufficient 4, 2

Safety Considerations and Side Effects

• Monitor hematocrit levels, as testosterone therapy can increase red blood cell production and potentially cause polycythemia 5
• If hematocrit rises above the reference range, consider temporarily withholding therapy, reducing the dosage, or performing phlebotomy 4
• Injectable testosterone creates fluctuating serum testosterone levels with peaks occurring 2-5 days post-injection and returning to baseline by 10-14 days 5, 4
• Higher doses and less frequent administration schedules may lead to greater fluctuations in testosterone levels, potentially causing mood swings and variable sexual function 5, 2

Common Pitfalls to Avoid

• Ensure proper diagnosis of hypogonadism with at least two separate morning testosterone measurements before initiating therapy 2, 6
• Be aware that intramuscular injections of testosterone cypionate can cause significant fluctuations in testosterone levels compared to other formulations 5, 2
• Avoid supraphysiologic doses, as they may increase the risk of adverse effects without additional clinical benefit 5
• Consider cardiovascular risk factors when selecting patients for testosterone therapy, as there may be increased risk in certain populations 2

Alternative Formulations

• If patients experience significant mood or energy fluctuations with intramuscular injections, consider alternative formulations such as transdermal preparations or longer-acting injectable testosterone undecanoate 6, 3
• Testosterone undecanoate (Aveed) offers a longer-acting option with injections every 10 weeks after initial loading doses, providing more stable testosterone levels 6
• Subcutaneous administration of testosterone enanthate at lower weekly doses (50-100 mg) has been shown to provide stable testosterone levels with less pain and easier self-administration 7, 8