Answer
Apr 22, 2026 - 02:13 PM
Micronor (norethindrone 0.35 mg) is a progestin-only birth control pill, sometimes called the “mini-pill.” The most common side effect is a change in menstrual bleeding.
Common side effects can include:
- Irregular periods, spotting, or breakthrough bleeding
- Headache
- Breast tenderness
- Nausea
- Dizziness
- Acne
- Weight gain
- Increased facial or body hair
Some people may also have periods that become less frequent or stop altogether. Irregular bleeding is particularly common with progestin-only pills and does not necessarily mean the medication is not working.
Contact your healthcare provider promptly if you experience unusually heavy or prolonged vaginal bleeding, persistent absence of periods, or severe abdominal or stomach pain. Severe abdominal pain is especially important to evaluate because pregnancy—including ectopic pregnancy—needs to be considered if pregnancy occurs while taking a progestin-only pill.
Also seek medical attention if you develop a new severe headache or migraine with neurological symptoms, such as vision changes, numbness, or weakness. The Micronor labeling recommends stopping the progestin-only contraceptive and evaluating recurrent or persistent severe headaches with focal neurological symptoms.
