Will premarin cause weight gain?

Premarin (conjugated estrogens) is used to treat menopausal symptoms like hot flashes, vaginal dryness, and night sweats. Common side effects include headache, breast pain, nausea, insomnia, depression, and stomach pain. Many women worry that Premarin may lead to weight gain.

Menopause and weight changes

Declining estrogen during menopause can slow metabolism and promote fat storage. Studies suggest women may gain an average of up to 10 kg (22 lb) during the menopausal transition.

Estrogen therapy and weight

• Clinical data on hormone replacement therapy (including Premarin) show mixed results: some women gain weight, others do not.
• Individual responses vary based on therapy duration and personal factors.
• Lifestyle factors—age, diet, exercise, genetics—often play a larger role in weight change than estrogen levels alone.
• If you experience significant weight gain after starting Premarin, notify your healthcare provider.

Other side effects of Premarin

• Abdominal pain and bloating
• Breast tenderness or enlargement
• Depression or mood changes
• Nausea and back pain
• Vaginal discharge and fluid retention
• Headache and leg cramps
• Melasma (skin pigmentation changes)
• Pelvic pain
• Rare serious risks: stroke, heart attack, blood clots, dementia, ovarian/breast/endometrial cancer, high blood pressure, liver and gallbladder disease, severe allergies, uterine fibroids

How Premarin works

Premarin contains conjugated estrogens derived from pregnant mare urine. It replaces declining estrogen after menopause, relieving symptoms of vaginal atrophy, and can also be used in hormone‑sensitive cancers and postmenopausal osteoporosis.

What to avoid when taking Premarin

• Do not smoke—smoking raises cardiovascular and clotting risks.
• Avoid grapefruit and grapefruit juice (can alter estrogen levels).
• Do not use if you have undiagnosed vaginal bleeding, liver disease, bleeding disorders, planned major surgery, or history of heart attack, stroke, blood clots, or hormone‑dependent cancers.
• Boxed warning: estrogen alone increases endometrial cancer risk; do not use for heart disease or dementia prevention.
• Inform your provider about conditions such as hysterectomy status, cardiovascular disease, asthma, migraines, seizures, lupus, thyroid disorders, and eye conditions.

Does Premarin cause fluid retention?

Yes. Estrogens can cause fluid retention, which may worsen heart, kidney, asthma, or seizure conditions. Report unusual swelling to your provider immediately.

Sources

• Menopause: Nutrition and weight gain. British Menopause Society. Accessed Jan 20, 2025.
• Anderson GL et al. Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the WHI trial. JAMA. Accessed Jan 20, 2025.
• Premarin (conjugated estrogens) Tablets, USP. Pfizer. Last updated 02/2024. Accessed Jan 20, 2025.