Testosterone Gel Treatment for Hypogonadism
Transdermal testosterone gel is the recommended first-line treatment for hypogonadism, with a starting dose of 40.5 mg applied once daily to the shoulders and upper arms, adjustable between 20.25-81 mg based on serum testosterone monitoring. 1, 2
Diagnosis Confirmation
Before initiating testosterone gel therapy:
- Confirm hypogonadism diagnosis with morning serum testosterone measurements on at least two separate days showing levels below normal range 2
- Evaluate for signs and symptoms of hypogonadism: decreased energy, libido, muscle mass, body hair, hot flashes, gynecomastia, infertility 1
- Measure morning total testosterone between 8-10 AM, free testosterone by equilibrium dialysis, and sex hormone-binding globulin (especially in obese patients) 1
- Measure LH and FSH to distinguish primary (testicular) from secondary (pituitary-hypothalamic) hypogonadism 1
Recommended Treatment Protocol
Formulation and Dosing
- Initial dose: 40.5 mg testosterone gel 1.62% (2 pump actuations or single 40.5 mg packet) applied once daily in the morning 2
- Dose adjustment range: 20.25-81 mg based on serum testosterone levels 2
- Application site: Clean, dry, intact skin of upper arms and shoulders only 2
Dose Titration Guidelines
- Measure pre-dose morning serum testosterone at approximately 14 and 28 days after starting treatment 2
- Adjust dose according to serum levels:
750 ng/dL: Decrease daily dose by 20.25 mg
- 350-750 ng/dL: No change, continue current dose
- <350 ng/dL: Increase daily dose by 20.25 mg 2
Administration Instructions
- Apply gel to upper arms and shoulders only (area covered by short sleeve t-shirt) 2
- Use palm of hand to spread gel across maximum surface area 2
- Allow application site to dry before covering with clothing 2
- Wash hands thoroughly with soap and water after application 2
- Avoid swimming, showering, or washing application site for minimum 2 hours after application 2
- Avoid fire, flames, or smoking until gel has dried (alcohol-based products are flammable) 2
Monitoring Protocol
- Test testosterone levels 2-3 months after treatment initiation and after any dose change 1
- Once stable levels are confirmed, monitor every 6-12 months 1
- Target mid-normal testosterone range (500-600 ng/dL) 1
- For patients using transdermal preparations, levels can be measured at any time, with understanding that peak values occur 6-8 hours after application 1
- Monitor for potential adverse effects: hematocrit elevation, prostate-specific antigen changes 1, 3
Advantages of Testosterone Gel
- Produces stable day-to-day testosterone levels compared to injections 1
- Avoids discomfort of intramuscular injections 1
- Generally more convenient for patients 1
- Lower risk of supraphysiologic testosterone levels compared to injections 1, 4
- Improved sexual function, mood, muscle strength, and body composition parameters 3
- Better skin tolerability compared to testosterone patches 3
Potential Limitations and Precautions
- Risk of inadvertent transfer to others via prolonged skin contact 1
- Variable absorption from gels in some patients 1
- Higher cost compared to injectable options 1
- FDA warning regarding possible increased risk of cardiovascular events 1
- Potential for erythrocytosis (increased hematocrit), requiring monitoring 1
Alternative Application Sites
While the FDA-approved application site is the upper arms and shoulders, research shows:
- Arms/shoulders provide the best absorption and highest testosterone levels 5
- Chest/abdomen provides adequate but somewhat lower levels 5
- Legs/calves provide the lowest absorption 5
If alternative application sites are used, more frequent monitoring of testosterone levels is recommended to ensure adequate therapeutic levels 5.