Switching from Oral Testosterone Undecanoate to Topical Testosterone
When switching from oral testosterone undecanoate to topical testosterone, clinicians should target a total testosterone level in the middle tertile of the normal reference range (450-600 ng/dL) using the minimal effective dose of topical testosterone. 1, 2
Dosing Recommendations
Start with standard initial doses of topical testosterone preparations 1, 2:
- 1.62% testosterone gel: 40.5 mg (2 pumps) applied once daily
- 1% testosterone gel: 50 mg (one 5-g packet) applied once daily
- Testosterone patches: 4 mg/day (two 2-mg patches) applied once daily
Measure testosterone levels 2-3 months after initiating topical therapy to assess if dose adjustments are needed 2
For patients previously on oral testosterone undecanoate (typically dosed at 225 mg twice daily), expect that approximately 87% will achieve normal testosterone levels with standard topical dosing 3
Monitoring Recommendations
For topical preparations, testosterone levels can be measured at any time after reaching steady state, as levels remain relatively stable throughout the day 1, 2
Target testosterone levels in the mid-normal range (450-600 ng/dL) for optimal efficacy and safety 1
Once stable levels are achieved, monitor testosterone levels every 6-12 months 2
Clinical Considerations
Topical testosterone preparations provide more stable day-to-day testosterone levels compared to injectable formulations, with fewer fluctuations between peak and trough levels 4
Patients switching from oral to topical testosterone may experience improved quality of life measures, including mental health benefits 3, 4
Be aware that topical testosterone carries a risk of transfer to women and children through skin contact; counsel patients on proper application and washing hands thoroughly after use 1
Commercially manufactured testosterone products should be prescribed rather than compounded testosterone when possible due to greater consistency in potency and quality 1
Safety Considerations
Monitor for erythrocytosis, which occurs less frequently with topical preparations (2.8-17.9% depending on dose) compared to injectable testosterone (43.8%) 1
Topical preparations may be preferable for patients with cardiovascular risk factors, as they provide more physiologic testosterone levels with less fluctuation 1, 4
Avoid initiating testosterone therapy within 3-6 months of cardiovascular events 1
Counsel patients that testosterone therapy should not be used in men trying to conceive due to suppression of spermatogenesis 1
Application Instructions
Apply topical testosterone to clean, dry skin of the shoulders, upper arms, or abdomen (depending on specific product instructions) 1
Avoid washing the application site for at least 2 hours after application 1
Inform patients about the risk of transfer to others and advise them to cover the application site with clothing after the gel has dried 1