Women may not have regular periods while they are taking progestin-only pills. Periods may become irregular, light, or more frequent or may stop altogether. This usually improves within the first 6 months of use, and is not harmful, but some women may find it annoying. Changing to a different brand of pill may help but there is not data on this.
The progestin-only pill does not protect against sexually transmitted infections, so women may need to use condoms as well.
Women must remember to take the pill at the same time every day.