Do I need to use condoms when switching birth control pills?

Dear Alice,

I love your site, Alice. It has helped me a lot. I found that no one has asked this on here from what I've seen so far. I was wondering about when you switch birth control pills. I was on Diane 35 and then I switched to Tricyclen, and I was wondering if it was safe to have sex without condoms before waiting for the second month because they are both birth control pills.

Dear Reader, 

Your question about the safety of having unprotected sex when switching pills is valid. The answer largely depends on what you mean by "safety". Are you concerned about the efficacy of birth control pills at preventing pregnancy, side effects of taking birth control pills, risk of getting sexually transmitted infections (STIs), or something else? In general, birth control pills are 99 percent effective at preventing pregnancy if used according to the prescription medication instructions, or your health care provider’s directives. However, the pill becomes less effective if you don’t follow the guidelines provided. Additionally, that efficacy may change if someone’s vomiting or experiencing diarrhea within 48 hours of taking the pill, as well as taking certain medications or supplements

When switching birth control pills, your health care provider may discuss a few methods for making the switch. For instance, your provider may recommend starting the new pack immediately without any time gaps or placebo pills (inactive pills that don’t have hormones). Another strategy is the overlap method, which involves an overlap of both the old and new contraceptive for a few days in order to give the new contraceptives time to take effect. When switching to combination pills, those that contain estrogen and progestin, in particular, you may want to use back-up contraception for at least seven days afterward to ensure that your hormone levels have adjusted to prevent pregnancy. 

After your switch, you may experience side effects lasting around two to three months as your body adjusts to the different ingredients in the new pill. It’s also important to note that birth control pills do not protect against STIs. That said, it's generally wise to use a barrier method like condoms or dental dams during sexual activity to lower your risk of getting an STI. 

Looking to understand the potential risks that come from switching birth control is a great step in your health journey. If you have any further concerns, you may consider seeing a health care provider who can give you personalized recommendations for your needs. 

Stay safe,   

Last updated Jan 05, 2024
Originally published Jul 23, 2004