Kariva is a low-dose combination birth control pill that contains desogestrel and ethinyl estradiol. It works by preventing ovulation, thickening cervical mucus, and thinning the uterine lining to reduce the chance of pregnancy. In addition to birth control, Kariva can help regulate your period and reduce menstrual cramps. It’s a reliable, affordable option with the same active ingredients as some branded pills — and it ships free if prescribed.