Both synthetic and natural estrogens can be absorbed via the skin and mucous membranes and produce systemic effects.
Natural estrogens are inactive orally due to rapid metabolism in liver.
Estradiol esters injected I.M are slowly absorbed and exert prolonged action. Ethinylestradiol and stilbestrol are metabolised very slowly-orally active and more potent. Indications Estrogen may relieve the postmenopausal symptoms, such as hot flushes and unusual sweating, chills, faintness, or dizziness. Routes of Administration and Dosage Estradiol, micronized 1 mg, 2mg tablets orally. Estrogens can increase the chances of toxic effects in the kidney or liver from cyclosporine because estrogens can interfere with the body's ability to extract the cyclosporine from the blood.