Ovral L is a low-dose combined oral contraceptive containing levonorgestrel (0.15mg) and ethinyl estradiol (0.03mg) that prevents pregnancy through the same mechanisms as other birth control pills - stopping ovulation, thickening cervical mucus, and thinning the uterine lining. As a lower-dose formulation compared to Ovral G, it typically causes fewer side effects while maintaining contraceptive effectiveness, making it suitable for women who may be sensitive to higher hormone doses.