What is the difference between Opill and the combined birth control pill?

There are many different brands of birth control pills, but only two main categories of pill—the mini-pill (progestin-only pill) and the combined birth control pill. Both types of birth control pills contain hormones.

The biggest difference between them is how you use them and which hormones they contain. The mini-pill only contains progestin. Combination birth control pills contain both estrogen and progestin. Opill, also available in a store brand called “norgestrel daily oral contraceptive,” is a progestin-only birth control pill (also called the mini-pill), that is available over the counter. That means you don’t need a prescription to get it.

If you use the progestin-only pill, or mini-pill, you have to be much more careful to take your pill at the same time every day. If you are more than 3 hours late taking the mini-pill (unless you’re using the brand Slynd, which offers more flexibility), you will need to use a backup method of birth control for the next 48 hours. With the combination pill, you just need to make sure to take a pill a day—the timing doesn’t matter.