Key takeaways
Premarin (conjugated estrogens) and Climara (topical estradiol patch) are both estrogen replacement medications used to treat menopausal symptoms such as hot flashes and vaginal dryness, and to prevent osteoporosis after menopause. However, they differ in several ways. Premarin is a daily oral tablet, while Climara is a transdermal patch applied once a week. Premarin is not available as a generic, whereas Climara has a lower-cost generic option. Premarin is also used for certain advanced stages of breast and prostate cancers, which is not an indication for Climara. Common side effects of Premarin include headache, stomach pain, and breast pain, while Climara may cause skin irritation at the patch site, breast pain, and headaches. Both medications can increase the risk of blood clots, strokes, and certain cancers, and may require the addition of a progestin if you have a uterus to lower the risk of uterine cancer.
