What is the recommended dosage and administration protocol when switching a patient from testosterone injections to AndroGel (testosterone gel)?

Switching from Testosterone Injections to AndroGel

Start AndroGel 1% at 50-100 mg daily (one to two 5-gram packets or pump actuations) applied to the shoulders and upper arms, then measure testosterone levels at 2-3 months to titrate the dose targeting mid-normal range of 450-600 ng/dL. 1

Initial Dosing Strategy

• Begin with the standard starting dose of 50 mg daily (one 5-gram packet of AndroGel 1%) regardless of the previous injection dose. 2
• The standard dose range for AndroGel 1% is 50-100 mg daily, providing flexibility for upward titration based on subsequent testosterone levels. 1, 2
• For AndroGel 1.62%, the equivalent starting dose is 40.5 mg daily (two pump actuations), which delivers similar testosterone absorption. 3

Application Technique

• Apply the gel to clean, dry, intact skin of the shoulders and upper arms only—the area that will be covered by a short-sleeve t-shirt. 3
• Do not apply to the abdomen, genitals, chest, armpits, or knees, as absorption varies significantly by anatomical site (arms/shoulders provide superior absorption compared to chest/abdomen or legs). 3, 4
• Allow the application site to dry completely before dressing, then cover with clothing to minimize transfer risk. 3
• Patients must wash hands thoroughly with soap and water immediately after application. 1, 3
• Avoid swimming, showering, or washing the application site for a minimum of 2 hours after application to ensure adequate absorption. 3

Monitoring and Dose Titration Protocol

• Measure total testosterone levels 2-3 months after initiating gel therapy to allow steady-state levels to be achieved. 1, 2
• Target testosterone levels in the middle tertile of normal range: 450-600 ng/dL. 1, 2
• For gel formulations, testosterone levels should be measured as a pre-dose morning level (unlike injections where mid-cycle timing is used). 1
• If testosterone levels are below 450 ng/dL at the 2-3 month check, increase the dose by 20.25-25 mg increments (one pump actuation). 2, 3
• If levels exceed 750 ng/dL, decrease the daily dose by 20.25 mg. 3
• Once stable levels are achieved, continue monitoring every 6-12 months. 1

Additional Safety Monitoring

• Monitor hematocrit/hemoglobin at each visit, as erythrocytosis risk is significantly lower with transdermal preparations (15.4%) compared to intramuscular injections (43.8%). 1
• Check prostate-specific antigen (PSA) in men over 40 years old at baseline and periodically thereafter. 2
• Assess for cardiovascular symptoms at each visit, though transdermal preparations may carry lower cardiovascular risk than injectable formulations due to more stable testosterone levels. 1

Critical Safety Precautions for Transfer Risk

• Warn patients that skin-to-skin contact with partners or children can transfer testosterone before the gel dries and the site is covered. 1, 2
• Instruct patients to cover application sites with clothing once dry and to wash the area thoroughly with soap and water before any anticipated skin-to-skin contact. 3
• If unwashed or unclothed skin contacts another person, that person should immediately wash the contact area with soap and water. 3

Advantages of This Transition

• Transdermal testosterone provides more stable day-to-day testosterone levels compared to the significant fluctuations seen with biweekly injections (peak levels 2-5 days post-injection, returning to baseline by 10-14 days). 1, 5
• Dose adjustments are simple and immediate with gel, unlike injections which require waiting for the next injection cycle. 2
• The gel formulation has significantly lower risk of erythrocytosis and potentially lower cardiovascular risk due to avoiding supraphysiological peak levels. 1
• Quality of life scores show improved physical and emotional well-being with daily gel compared to intermittent injections. 5

Common Pitfalls to Avoid

• Do not assume equivalence between different gel formulations—AndroGel 1.62% delivers more testosterone per gram than AndroGel 1%, requiring different dosing. 1
• Do not apply gel to non-recommended sites (abdomen, chest) as this significantly reduces absorption and therapeutic efficacy. 3, 4
• Do not skip the 2-3 month monitoring window, as this is essential to ensure adequate testosterone replacement and avoid both under- and over-treatment. 1, 2
• The 50 mg starting dose minimizes risk of supraphysiologic levels while the monitoring protocol ensures adequate replacement. 2