Ingenus Pharmaceuticals announced the U.S. Food and Drug Administration (FDA) approval and commercial launch of Conjugated Estrogens Tablets, USP, the first FDA-approved generic equivalent to Premarin Tablets. The product became available immediately to customers nationwide on November 13, 2025.
Generic Launch Expands Treatment Access
The generic formulation is available in all FDA-approved strengths: 0.3 mg, 0.45 mg, 0.625 mg, 0.9 mg, and 1.25 mg. "The availability of the first generic version of Premarin Tablets represents a significant step forward in expanding access to this important therapy," said Paul Dutra, Executive Vice President at Ingenus Pharmaceuticals. "We are proud to continue our mission of delivering high-quality, affordable medicines to patients who need them."
This launch marks a major milestone for Ingenus Pharmaceuticals in its growing women's health and complex generics portfolio.
Therapeutic Indications and Usage
Conjugated Estrogens Tablets is indicated for the treatment of moderate to severe vasomotor symptoms due to menopause and the prevention of postmenopausal osteoporosis. When prescribing solely for the prevention of postmenopausal osteoporosis, therapy should only be considered for women at significant risk of osteoporosis and non-estrogen medications should be carefully considered.
Safety Profile and Clinical Evidence
The product carries significant safety considerations based on extensive clinical trial data. The Women's Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women with daily oral conjugated estrogens (CE) 0.625mg alone relative to placebo. The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism, stroke, and myocardial infarction in postmenopausal women with daily oral CE 0.625mg combined with medroxyprogesterone acetate (MPA) 2.5mg relative to placebo.
The WHI Memory Study (WHIMS) reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older, in both the estrogen alone and estrogen plus progestin arms. It is unknown whether these findings apply to younger postmenopausal women.
Cancer Risk Considerations
There is an increased risk of endometrial cancer in women with a uterus who use unopposed estrogens. Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. The WHI estrogen plus progestin substudy demonstrated an increased risk of invasive breast cancer.
Consistent with the WHI clinical trials, observational studies have also reported an increased risk of breast cancer for estrogen plus progestin therapy, and a smaller increased risk for estrogen-alone therapy, after several years of use. One large meta-analysis of prospective cohort studies reported increased risks that were dependent upon duration of use and could last up to more than 10 years after discontinuation of estrogen plus progestin therapy and estrogen-alone therapy.
Prescribing Guidelines
Estrogens with or without progestins should be prescribed at the lowest effective dose and for the shortest duration consistent with treatment goals and risks for the individual woman. The therapy should not be used for the prevention of cardiovascular disease or dementia.
The most common adverse reactions (≥ 5 percent) are abdominal pain, asthenia, pain, back pain, headache, flatulence, nausea, depression, insomnia, breast pain, endometrial hyperplasia, leucorrhea, vaginal hemorrhage, and vaginitis.
