Progestin only birth control pill is sometimes called the “mini-pill” as it contains only synthetic progesterone hormone which is a naturally occurring hormone in women. Most birth control pills contain two of the female hormones, progesterone and estrogen. There are fewer side effects with the progestin only pills. Women who have slightly elevated blood pressure are usually proscribed this form of the birth control pill, however it is not recommended that women with high blood pressure continue to use birth control as it tends to be one of the side effects and elevates the blood pressure more.

Some of the other side effects that may be caused by regular birth control pills are as follows:

- Nausea
- Headaches
- High blood pressure
- Depression
- Mood swings
- Cysts in the breasts

The progestin pill is safer women who smoke, over weight, have a history of blood clots or who are over 35. Women who are breast feeding should also be prescribed this form of birth control while nursing as it does not change milk production or the quality of it. Estrogen may cause these changes to occur.