Studies revealed that the rate of failure is 1 per cent and regulate the mensstrual periods in case the Yas used regularly as per the directions of a medical practitioner. In case the pills is not used regularly, then the rate of failure will be 5 per cent per year.
When taken correctly without missing any pills, YAZ has failure rate of approximately 1% per year (1 pregnancy per 100 women per year of use). Including women who miss pills the failure rate is approximately 5% per year (5 pregnancies/100 women/year of use).
I believe the failure rate for Yaz and Yasmin is much higher than reported, even when taken correctly. As a pharmacologist and a clinician, In the past 5 months have encountered 6 women who have become pregnant while on Yaz.
When used correctly, Yaz is 99% effective in preventing pregnancy. That means that 1 in 100 women using Yaz will get pregnant. Your chances of getting pregnant are higher if you do not use Yaz as prescribed by your doctor.