Last reviewed 2026-04-20 · How we verify

NORETHINDRONE

Norethindrone, a marketed progestin, is widely used for preventing pregnancy through mechanisms that prevent ovulation and alter cervical mucus. Its key strength lies in its established market presence and well-understood mechanism of action, though it faces competition from newer agents like Levonorgestrel and Desogestrel, which offer longer-lasting effects and fewer side effects. The primary risk is the key composition patent expiry in 2028, which could lead to increased generic competition and potential revenue erosion.

At a glance

Approved indications

• Prevention of pregnancy

Pipeline indications

• Endometriosis — Phase 3
• Uterine fibroids — Phase 3

Boxed warnings

• WARNING: CIGARETTE SMOKING AND SERIOUS CARDIOVASCULAR EVENTS Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive (COC) use. This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. For this reason, COCs, including Hailey 1.5/30, are contraindicated in women who are over 35 years of age and smoke (see CONTRAINDICATIONS and 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 are strongly advised not to smoke.

Common side effects

• Nausea
• Vomiting
• Gastrointestinal symptoms
• Breakthrough bleeding
• Spotting
• Change in menstrual flow
• Amenorrhea
• Edema
• Melasma
• Breast changes
• Change in weight
• Cholestatic jaundice

Drug interactions

• Hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir

Key clinical trials

• Effects of VX-407 on the Pharmacokinetics of Oral Contraceptives in Healthy Participants (PHASE1)
• A Trial to Examine the Interaction of Repinatrabit With Ethinyl Estradiol/Norethindrone, Metformin,Carbamazepine, Rosuvastatin, and Methotrexate When Administered Together (PHASE1)
• Relative Desirability of Metformin vs. Birth Control Pill in Treating PCOS in Women of Later Reproductive Age (EARLY_PHASE1)
• Estradiol-mediated Inflammation and Central Sensitization in the Pathophysiology of Endometriosis-associated Pelvic Pain (PHASE3)
• Study of the Safety and Contraceptive Efficacy of Relugolix Combination Therapy in Women With Uterine Fibroids or Endometriosis Who Are at Risk for Pregnancy (PHASE3)
• Ovulation Incidence in Oral Contraceptive Users (PHASE3)
• A Randomized Feasibility Trial Comparing Drospirenone and Norethindrone for Postpartum Hypertension Management in Preeclampsia (PHASE4)
• Heavy Menstrual Bleeding Progestin Treatment in Bleeding Disorders Study

Patents

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:

• NORETHINDRONE CI brief — competitive landscape report
• NORETHINDRONE updates RSS · CI watch RSS