Daria asked
Hello! I am currently taking Yaz pills. The instruction states that if you are less than 24 hours late when taking the pill, contraceptive effect is not reduced. Why do some sources on the internet state that contraceptive effect is reduced after being 12 hours late?Are my pill instructions telling me the wrong information? I have read them multiple times. They state exactly: if you are less than 24 hours late when taking a tablet, the protection against pregnancy is not reduced. What do I trust?
Answer
If you miss one dose of Yaz (Drospirenone; Ethinyl Estradiol), most sources state that you do not need to use back-up contraception (e.g. condoms) and contraceptive efficacy of the pill is not reduced. Per the United States prescribing information for Yaz:
"If you MISS 1 light pink "active" pill: 1. Take it as soon as you remember. Take the next pill at your regular time. This means you may take two pills in one day. 2. You do not need to use a back-up birth control method if you have sex."While the prescribing information for Yaz in the United States states that back-up contraception isn't needed and you are still protected from pregnancy, the prescribing information for Yaz in the Netherlands does offer a different, more conservative recommendation if you miss one Yaz pill during the first week:
"If you are more than 12 hours late taking a tablet, the protection against pregnancy may be reduced. The greater the number of tablets that you have forgotten, the greater is the risk of becoming pregnant.The prescribing information for Yaz does not offer any studies or references regarding their recommendation. In fact, the vast majority studies have found that one missed dose of a combined hormone birth control pill, such as Yaz, does not increase the risk of ovulation and therefore does not increase the risk of pregnancy.
Take the forgotten tablet as soon as you remember, even if that means that you have to take two tablets at the same time. Continue taking the tablets at the usual time and use extra precautions for the next 7 days, for example, a condom. If you have had sex in the week before forgetting the tablet you must realize that there is a risk of pregnancy. In that case, contact your doctor."
Both the CDC (Centers For Disease Control) guidelines and WHO (World Health Organization) guidelines for missed doses of combined hormone birth control pills do not recommend the use of back-up or emergency contraception after one missed dose, as long as you have taken your other pills consistently.
Summary
While not taking your birth control pills consistently at the same time every day most likely does reduce their efficacy slightly, the vast majority of studies report that ovulation is still inhibited and you are therefore protected from pregnancy after missing one dose of Yaz, as long as you follow the appropriate directions for what to do after missed pills.
