Where can topical hormone preparations be applied?

Application Sites for Topical Hormone Preparations

Topical testosterone gel should be applied exclusively to the upper arms and shoulders, with the application area limited to what would be covered by a short-sleeve t-shirt; application to the abdomen, genitals, chest, armpits, or knees is explicitly contraindicated. 1

Testosterone Preparations: FDA-Approved Application Sites

Primary Recommendation

• Testosterone gel 1.62% must be applied to clean, dry, intact skin of the upper arms and shoulders only 1
• The FDA label explicitly states: "Do not apply testosterone gel 1.62% to any other parts of the body, including the abdomen, genitals, chest, armpits (axillae), or knees" 1
• The application area should be limited to the region that will be covered by a short-sleeve t-shirt 1

Distribution Pattern

• For doses requiring multiple applications, the gel should be distributed between the right and left upper arms/shoulders 1
• Application can be made to one or both shoulders depending on the total dose prescribed 1

Critical Safety Precautions

• The application site must be covered with clothing (e.g., a t-shirt) after the gel has dried to prevent secondary exposure to others 1
• Patients must wash hands thoroughly with soap and water immediately after application 1
• Children and women should avoid contact with unwashed or unclothed application sites 1
• Patients should avoid swimming, showering, or washing the application site for a minimum of 2 hours after application 1

Alternative Application Sites: Research Evidence vs. FDA Guidance

Abdomen Application

• While some research studies have evaluated testosterone gel application to the abdomen 2, 3, 4, this is explicitly contraindicated by current FDA labeling 1
• One study found that application to four sites (arms/shoulders and abdomen) resulted in only 23% higher testosterone levels compared to single-site application, suggesting minimal clinical benefit 2
• The modest increase in absorption does not justify deviation from FDA-approved sites given safety concerns about secondary exposure 1

Scrotal Application

• Research has evaluated scrotal application of testosterone gel, showing effective absorption 5
• However, scrotal application is not FDA-approved and should not be used in routine clinical practice 1
• The genital area is explicitly listed as a contraindicated application site 1

Leg/Calf Application

• One study evaluated application to calves/legs and found it produced lower testosterone levels compared to arms/shoulders 4
• This site is not FDA-approved and should be avoided 1

Topical Corticosteroid Application Sites

Location-Specific Potency Selection

• For face and neck: Use only mild-to-moderate potency corticosteroids (hydrocortisone 1-2.5% or clobetasone butyrate 0.05%) 6
• For body, trunk, and extremities: Potent corticosteroids (betamethasone valerate 0.1%, mometasone 0.1%) can be safely used 6
• For severe conditions requiring very potent steroids: Clobetasol propionate 0.05% can be applied to lesional skin or the entire body surface (5-15 g twice daily) if the patient or caregiver is capable 7

Genital Application

• Very potent topical corticosteroids like clobetasol propionate can be applied to genital areas for conditions like lichen sclerosus 7
• For vulval lichen sclerosus, the recommended regimen is clobetasol propionate once nightly for 4 weeks, then alternate nights for 4 weeks, then twice weekly 7
• Male genital lichen sclerosus can also be treated with clobetasol propionate applied to affected areas 7

Common Pitfalls to Avoid

Testosterone Gel Application Errors

• Never apply testosterone gel to the abdomen, chest, or genitals despite older research suggesting these sites—current FDA guidance supersedes historical studies 1
• Do not assume all topical testosterone products have the same application sites—different formulations have different approved sites and are not interchangeable 1
• Failure to cover application sites with clothing after drying creates serious risk of secondary exposure to women and children 1

Corticosteroid Application Errors

• Avoid using potent or very potent corticosteroids on the face and neck due to increased risk of skin atrophy and other adverse effects 6
• Do not apply topical steroids to infected skin without concurrent antimicrobial therapy 7
• Inadequate quantities lead to under-treatment—adults require approximately 15-30g per 2 weeks for face/neck, 30-60g for both arms, 100g for both legs, and 100g for trunk 6