Estradiol Patch to Gel Conversion
Half of an Evorel 75 patch (37.5 mcg/day) converts to approximately 0.5-0.75 mg of Estrogel daily.
Conversion Rationale
The Evorel 75 patch delivers 75 mcg of estradiol per 24 hours, so half a patch provides approximately 37.5 mcg/day 1. Standard transdermal patches releasing 50 mcg/24 hours are considered equivalent to 0.5-1 mg of transdermal gel daily 2, 1. Using proportional dosing, half of a 75 mcg patch (37.5 mcg) would correspond to approximately 0.5-0.75 mg of Estrogel.
Specific Dosing Recommendation
- Start with 0.5 mg Estrogel daily as the most conservative equivalent dose 1
- If symptoms persist after 2-3 months, increase to 0.75 mg daily 1
- The typical dose range for transdermal gel is 0.5-1 mg daily, which achieves plasma estradiol levels of 35-100 pg/ml 3
Application Instructions
- Apply Estrogel to clean, dry skin on the lower abdomen, upper outer arm, or thighs 1
- Allow gel to dry completely before dressing (typically 2-5 minutes) 4
- Rotate application sites to minimize skin irritation 1
Critical Endometrial Protection
If you have an intact uterus, you must add progestin supplementation to prevent endometrial hyperplasia and cancer 2, 1:
- Micronized progesterone 200 mg orally or vaginally for 12-14 days every 28 days (first-line choice) 2, 5
- Alternative: Medroxyprogesterone acetate 10 mg daily for 12-14 days per month 2, 5
- Alternative: Dydrogesterone 10 mg daily for 12-14 days per month 2
Monitoring and Titration
- Assess symptom control after 2-3 months on the initial dose 1
- Plasma estradiol levels should reach 35-55 pg/ml minimum for efficacy 3
- If vasomotor symptoms persist, increase gel dose incrementally by 0.25 mg 4
Common Pitfall to Avoid
Do not assume direct mcg-to-mg conversion between patches and gels. While both are transdermal, gels have different absorption kinetics and surface area requirements compared to patches 4, 6. The gel requires a higher nominal dose (in mg) to achieve similar plasma levels as patches (in mcg/day) due to differences in delivery systems 6.