What should you know about progestogen-only pill side effects?

Spotting, irregular bleeding, longer bleeding, lighter periods, or no periods can happen because progestogen changes the lining of the womb. Some people also notice headache, nausea, breast tenderness, acne, or mood changes. These symptoms can have other causes, so a new or troubling symptom should not be assumed to come from the pill.

The POP does not contain oestrogen. [Levonorgestrel](/materials/levonorgestrel/) is an example of a progestogen used in some hormonal medicines, while the [Combined Pill](/treatments/contraception-and-family-planning/combined-pill/) also contains oestrogen.

Keep taking the pill as directed unless a clinician tells you to stop, and record bleeding days and other symptoms. Take the tablet at a consistent time, check for interactions with new medicines, and arrange a contraceptive review if side effects interfere with daily life or do not settle.

Do not double doses to compensate unless the product instructions specifically say to do so. If vomiting or severe diarrhoea occurs, check the pack advice because absorption may be reduced and backup contraception may be needed.

Get urgent help for severe chest pain, trouble breathing, one-sided leg swelling or pain, sudden weakness, or a severe allergic reaction. Seek prompt advice for severe abdominal pain, fainting, a positive pregnancy test, very heavy bleeding, or a marked mood change with thoughts of self-harm.

Ask whether your bleeding pattern is expected for your formulation, which alternatives could suit you, and whether another condition or medicine could explain your symptoms.