Should you use the pull-out method even when you're on birth control? A chart showing effectiveness

• If you're a typical user of birth control pills, pulling out could offer a little more protection.
• But if you're on a birth control method like an IUD or implant, then it's not necessary.

Whether they're having casual sex or in a committed relationship, preventing an unplanned pregnancy is extremely important to many people. In fact, 45% of pregnancies in the US are unplanned — so the risk is high.

To be extra safe, some couples might want to double-up on methods of protection by using the pull-out method in addition to another form of birth control (like the pill, IUD, etc).

Medical term: Pull-out method: The pull-out method is a form of birth control that involves removing the penis from the vagina before a person ejaculates. It's 78% effective at preventing unwanted pregnancy.

Although most forms of birth control are highly effective when used correctly, they all have some risk for unplanned pregnancy. Using the pull-out method as a backup birth control method can further decrease that risk.

Here's what you should know about the effectiveness of birth control and when pulling out is a good second layer of protection.

Pulling out could add more protection to the pill and other birth control

Any birth control has some potential for unexpected pregnancy. Adding the pullout method decreases that risk by an additional 78%, says Dr. Eva Shelton, a resident at Brigham and Women's Hospital.

So if you're on the pill, which is 91% effective with typical use, you have a 9% chance of an unplanned pregnancy. Adding in the pullout method further reduces that 9% down to 2%, Shelton says.

Note: To calculate how much additional protection the pullout method offers, take the risk of pregnancy and multiply it by 0.78. Then take the difference. So, in the case of the pill it's 9-(9*0.78).

However, if you're using a birth control method that's more than 99% effective — like an IUD, implant, tubal ligation, or vasectomy —the risk of pregnancy is so small already that the benefit of pulling out is negligible.

"Pulling out is an unnecessary addition to using reliable contraception," says sexuality educator Lawrence Siegel.

How effective is birth control?

Here's a breakdown of how effective common birth control options are on their own, and when you add in the benefit of pulling out too.

These effectiveness rates are with typical use. That accounts for the common mistakes — like missed pills or delayed appointments — that most people make, says Dr. Sherry Ross, OB-GYN.

Note: The pill is 99% effective with perfect use — meaning you take it at the exact same time each day. But most people don't use it perfectly, so the effectiveness is lowered.

If you're trying to prevent pregnancy, focus on methods like the implant or IUDs that have lower user error and are more consistent at preventing pregnancy, she says. And if you're using the pull-out method for added protection, make sure no semen touches the vulva or vagina.

"Birth control is only as effective as you are compliant," Ross says.

When should you double-up on birth control?

If you're comfortable with the risk of pregnancy that your primary birth control has, it's fine to have sex without pulling out, says Ross.

"People should feel comfortable using birth control when they are using these methods as prescribed," she says.

But if you want more peace-of-mind, pulling out in addition to using birth control can provide it by further reducing your risk of unplanned pregnancy.

In addition, it's important to double up on birth control if you need to protect yourself from sexually-transmitted infections, Seigel says. Condoms or female condoms are the only way to reliably prevent the transmission of STIs.

"To get the most peace of mind, use a condom, both on a penis and if sharing sex toys," Siegel says. "This will bring the safety factor as close to 100% as possible."

Best condoms

Our guide to the best condoms includes options for for every shape and size to help you have safe sex.

• Best overall: Lifestyles Skyn, $11.19 on Amazon
• Best for pleasure: One Pleasure Plus, $9.48 on One
• Best for sensitive skin: Durex Avanti Bare RealFeel Non-Latex, $14.05 on Amazon
• Best large: Kimono Microthin XL, $17.95 on Amazon

Insider's takeaway

The idea of an unplanned pregnancy can be terrifying, especially since abortion access has become limited in some states after the overturn of Roe vs. Wade.

Pulling out in addition to using birth control can reduce your risk of pregnancy by another 78%, providing peace-of-mind to people who are very concerned about unplanned pregnancies.

"Although highly effective, no birth control is 100% protective," says Shelton. "Therefore the safest way is to have a backup method."