Last reviewed 2026-04-20 · How we verify

ETHYNODIOL DIACETATE

Ethynodiol diacetate is a marketed drug primarily indicated for the prevention of pregnancy, holding a significant position in the contraceptive market. Its key strength lies in the protection of its composition patent, which is set to expire in 2028, providing a period of exclusivity. The primary risk is the potential increase in competition following the patent expiry in 2028.

At a glance

Approved indications

• Prevention of pregnancy

Boxed warnings

• Cigarette smoking increases the risk of serious cardiovascular side effects from oral contraceptive use. This risk increases with age and with heavy smoking (15 or more cigarettes per day) and is quite marked in women over 35 years of age. Women who use oral contraceptives should be strongly advised not to smoke. Cigarette smoking increases the risk of serious adverse effects on the heart and blood vessels from oral contraceptive use. This risk increases with age and with heavy smoking (15 or more cigarettes per day) and is quite marked in women over 35 years of age. Women who use oral contraceptives are strongly advised not to smoke. Cigarette smoking increases the risk of serious adverse effects on the heart and blood vessels from oral contraceptive use. This risk increases with age and with heavy smoking (15 or more cigarettes per day) and is quite marked in women over 35 years of age. Women who use oral contraceptives are strongly advised not to smoke.

Common side effects

• Nausea
• Vomiting
• Gastrointestinal symptoms (abdominal cramps and bloating)
• Breakthrough bleeding
• Spotting
• Change in menstrual flow
• Headache
• Breast tenderness
• Edema
• Change in weight
• Migraine
• Dizziness

Serious adverse events

• Thrombophlebitis and thrombosis
• Pulmonary embolism
• Myocardial infarction and coronary thrombosis
• Cerebral hemorrhage
• Cerebral thrombosis
• Arterial thromboembolism
• Benign and malignant liver tumors
• Mesenteric thrombosis
• Budd-Chiari syndrome
• Hemolytic uremic syndrome

Key clinical trials

• A Study To Determine Bioequivalence Between The Commercial Femulen Tablets And A Reformulation Of Femulen Tablets In Healthy Female Subjects (PHASE1)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• ETHYNODIOL DIACETATE CI brief — competitive landscape report
• ETHYNODIOL DIACETATE updates RSS · CI watch RSS