Yaz

YAZ uses 24 days of active pills followed by 4 days of inactive or "reminder" pills to round out the cycle. The 24-day active hormone pill regimen combined with the 30-hour half-life of drospirenone results in less hormonal ups and downs between cycles than when using the more traditional birth control pill.

Like all birth control pills, YAZ prevents pregnancy by providing hormones (estrogen and progestin) that suppress ovulation (the maturing and release of an egg) and other related changes your body goes through in preparation for a pregnancy.

If taken correctly on a daily basis, YAZ is as much as 99% effective in preventing pregnancy, but there is still a 1% chance that you could get pregnant. Furthermore, missing a pill or taking a pill a few hours later than normal can decrease the effectiveness. Certain medications like antibiotics are also known to increase the chance of your birth control pill failing.