Conjugated Estrogens (Premarin)


  • Hormonal  


  • Estrogen hormone


  • Menopausal vasomotor symptoms (hot flashes, etc.)

  • Atrophic vaginitis and kraurosis vulvae

  • Female hypogonadism

  • Female castration and primary ovarian failure

  • Breast cancer (palliation only)

  • Prostatic carcinoma

  • Osteoporosis prophylaxis

  • Postpartum breast engorgement

  • Abnormal uterine bleeding due to hormonal imbalance


  • Known or suspected breast cancer (except those being treated for metastatic disease)

  • Known or suspected estrogen-dependent neoplasia

  • Known or suspected pregnancy

  • Undiagnosed abnormal genital bleeding

  • Current or history of thrombophlebitis, thrombosis, thromboembolic disorders (except when used in breast or prostatic cancer treatment).


  • Pregnancy category X

  • Use with caution in nursing mothers and patients with hypertension, diabetes, asthma, epilepsy, migraine, cardiac or renal dysfunction, history of depression, pre-existing uterine leiomyotoma, history of jaundice during pregnancy, impaired liver function, metabolic bone disorders and in young women (and men).

  • Take with food to avoid GI side effects.

  • May decrease glucose intolerance in diabetic patients.

  • Discontinue therapy and contact health care provider if pregnancy is suspected.

Adverse Reactions (Side Effects):

  • Rash, acne, alopecia, hirsutism

  • Abnormal menstrual bleeding, changes in cervical secretions

  • Edema, weight change

  • Depression, insomnia, somnolence

  • Nausea


  • Administered orally, vaginally and IV injection

  • Menopausal vasomotor symptoms: 1.25mg per day

  • Atrophic vaginitis and kraurosis vulvae: 0.3-1.25mg orally, intravaginally and topically per day depending on tissue response

  • Female hypogonadism: 2.5-7.5mg per day in divided doses for 20 days, then rest for ten days, then repeat schedule until bleeding occurs

  • Female castration and primary ovarian failure: 1.25mg per day cyclically, adjusted to lowest dose for individual

  • Breast cancer (palliation only): 10mg tid for at least three months

  • Prostatic carcinoma: 1.25-2.5mg tid

  • Osteoporosis prophylaxis: 1.25mg per day, cyclically

  • Postpartum breast engorgement: 3.75mg q4h for 5 doses or 1.25mg q4h for 5 days

  • Abnormal uterine bleeding due to hormonal imbalance: 25mg IM or IV injection, repeat in 6-12 hours if needed

For more information on the use of conjugated estrogens, read:

Back to Medical Corps Pharmacy Page