3 things all women should know before starting Opill, the new OTC birth control, according to doctors

• The FDA just approved the first over-the-counter birth control pill in the US: OPill.
• OPill contains the hormone progestin, and it will become available in 2024.
• Doctors told Insider that OPill is safe for most people, but those with certain conditions should avoid it. 

Soon you'll be able to hit the drug store counter for all your basic necessities: toothpaste, cough drops, ibuprofen — and even birth control. 

On July 13, US officials approved the first over-the-counter birth control pill, called OPill. In 2024, any woman or girl in America, regardless of age, will be able  to buy contraceptive medication from a retail store without a prescription.

OPill was first introduced in 1973 and has been taken by millions of women with a prescription since then. Insider spoke to two doctors to find out what women should know before taking OPill over-the-counter. 

OPill is a progestin-only pill, which makes it pretty safe

OPill is a progestin-only birth control that is 93% effective and is very safe for most people, Dr. Lin-Fan Wang, a family physician at telehealth company, QueerDoc, told Insider. This makes it different from other forms of oral contraceptives which contain both estrogen and progestin. 

Progestin only birth control pills must be taken within the same 3 hour window everyday in order to be effective, and there's no week of placebo pills like you see with combined oral contraceptives. This means you might get your period during the fourth week, you might have intermittent bleeding (or "spotting") throughout the month, or you might not get your period at all. 

Progestin-only pills effectively protect against pregnancy after 48 hours on the pill. This is different than birth control pills that contain estrogen, which must be taken for one week in order to be effective.  

As a progestin-only pill, OPill is actually safer for more people than pills with estrogen. Pills with estrogen in them can increase risk of heart attack, stroke, blood clots and liver tumors, and they aren't advised for those at risk of these conditions.

"The addition of estrogen in a combined pill can carry additional risk," Dr. Tania Serna, an OB-GYN and complex family planning specialist at University of California, San Francisco, told Insider, "so just having the one hormone progestin is a very safe option for an over-the-counter product," Serna said.

Some women should still avoid it 

While OPill is generally considered to be safe, some women still shouldn't take it.

Wang recommends that those interested in trying OPill "read the packaging carefully" to ensure "that you don't have any of the special circumstances that make it unsafe for you."  

OPill isn't recommended for women with a history of breast cancer, as it can lead to tumor growth, or for those who have severe liver disease known as cirrhosis. If you have any abnormal vaginal bleeding, Wang recommends seeing a doctor first to make sure it's safe for you to take the medication. 

If you are sexually active, Wang also recommends take a pregnancy test prior to use, as OPill can slightly increase instances of an ectopic pregnancy. 

For some people, it could have side effects 

Anyone starting a new form of birth control should be aware that it can have side effects, said Serna. The most common side effects from OPill are bloating, minor headaches, and menstrual cycle changes. If you have any questions about OPill, Serna recommends seeing a "health care provider to see if it's still a good option, or if there's an alternative that might be better."

There are many different kinds of birth control options, Serna said, so if OPill isn't working for you, a medical professional can help you identify a different kind that's a better fit. 

"What I tell all people is that if you're starting birth control, it's all about finding the method that's right for you," Wang said, "you can always start and stop it."