 We now propose to move beyond proof of the principle that systemic administration of very low or low dose E2 is efficacious to the practical application of E2 treatment. Our study used IM depot E2 E2 cyclopentylpropionate, which is two-thirds E2, the very low doses of which required a compounding pharmacy to prepare a stock solution of 1.0 mgcc. This was helpful with compliance, but not necessarily accurate and certainly not convenient for routine dispensing of prescriptions. Practically, we propose to extrapolate from this experience with parenteral to the readily available and highly acceptable transdermal preparations: the 14 mcg patch worn for 10 days a month delivers an E2 profile approximately equivalent to the 0.2 mg monthly dose of depot E2, and a 25 mcg patch worn for 10 days a month is approximately equivalent to the 0.4 mg monthly dose of depot E2 7. 