Combined estrogen and progestin pills: what to know

They may also make bleeding more predictable and ease painful periods. The tablets must be taken according to the pack instructions, and they do not protect against sexually transmitted infections.

The estrogen and progestin are synthetic hormones. Different products use different hormone types and doses, so two packs described as combined pills are not necessarily interchangeable. Some packs include inactive tablets, while others have a tablet-free interval.

Temporary changes can include spotting, nausea, breast tenderness, headaches or mood changes. Bleeding during an inactive-tablet or pill-free interval is a withdrawal bleed, not proof that the pill is suitable or that pregnancy is impossible.

Before starting, give the prescriber an up-to-date blood-pressure reading and mention migraine with aura, smoking, previous blood clots, stroke, heart or liver disease, breast cancer, recent childbirth and breastfeeding. Also list medicines and herbal products because some can reduce contraceptive protection.

Take active pills in the correct order and set a daily reminder. If a tablet is late, missed, vomited, or followed by severe diarrhoea, use the leaflet for that exact pack or contact a pharmacist promptly. The response can depend on the product and where you are in the pack; emergency contraception or temporary condom use may be relevant.

Get urgent medical help for sudden shortness of breath, chest pain, coughing blood, one-sided leg swelling or pain, sudden weakness or numbness, trouble speaking, loss of vision, or a new severe headache unlike your usual headaches. These symptoms can signal a blood clot, stroke or another serious problem.

Arrange a routine review if bleeding remains troublesome, headaches change, mood symptoms become difficult, or you repeatedly miss tablets. Take a pregnancy test and seek advice if withdrawal bleeding is absent after pill errors or if you have pregnancy symptoms.

Ask which formulation fits your medical history, how your pack handles missed tablets, whether any current medicine interacts, and when blood pressure should be checked again. If period control is a goal, discuss whether a standard or extended regimen is appropriate for you.