The most common side effects of morning-after pills (emergency contraception) are typically mild and short-lived, including nausea, tiredness or fatigue, headache, breast tenderness, dizziness, and cramping that often resembles period pain[1][2][5][4].
Rare side effects may include vomiting (especially within two hours of taking the pill, requiring another dose), severe cramps, menstrual irregularities, and, less commonly, changes in vaginal bleeding such as spotting[1][2][4][5][7]. Breast discomfort and abdominal pain are also reported, but are less common[1][7][8]. These effects usually resolve within a day or so without the need for further treatment[4].
If you vomit within two hours of taking the emergency contraceptive pill, you may need to take another dose as the medication may not have been absorbed[1][4][5]. Consult a healthcare professional for advice if this occurs.
Emergency contraception can cause your next period to be slightly earlier or later than expected, and temporary irregular vaginal bleeding is possible[2][4][6].
Most users experience no serious or long-term health risks, and these pills do not affect future fertility[4]. If severe or persistent abdominal pain occurs, consult your healthcare provider.
References
- [1] Understanding the Morning After Pill: 10 Things You Should Know
- [2] Emergency Contraception: Possible Side Effects – Healthline
- [4] Emergency contraception – World Health Organization
- [5] Side effects of the emergency contraceptive pill (morning after pill) – NHS
- [6] What are the side effects of emergency contraception? – IPPF
- [7] Emergency contraception – PMC
- [8] Emergency contraception – Potential for women’s health – PMC