Objective: To evaluate serum estradiol (E2) in postmenopausal women who received 0.025 mg/d or 0.05 mg/d
transdermal estradiol, in an equivalent trial.
Material and Method: One hundred and eight postmenopausal women were randomized into 0.025 mg/d and
0.05 mg/d of transdermal E2 matrix patch. After 12 weeks, serum E2 and vaginal maturation index (VMI) were
checked in both groups. Adverse effects, such as breast tenderness, application site reaction, weight gain, and
headache, were also assessed.
Results: Serum E2 in 0.025 mg/d and 0.05 mg/d groups were 42.43 + 35.11 and 48.41 + 22.36 pg/mL,
respectively. There was no statistically significant difference between the groups. Equivalence was found
under CI of + 14 pg/mL. Mean value of superficial cells and vaginal maturation index (VMI) were comparable
between both groups. Adverse effects seem to be less in the lower dosage group compared to the standard
dosage group.
Conclusion: The lower dosage (0.025 mg/d) of the transdermal E2 matrix system is probably an appropriate
treatment option for postmenopausal women who need minimal effective and minimal adverse effects.

Keywords: Transdermal patch, Lower dosage, Serum estradiol, Menopause