How does the BC pill work, even during the placebo period? – Scarleteen The biological explanation for how the pill affects someone’s reproductive system to prevent pregnancy. Website Related Posts The Pill: Risks and Side Effects – About.com About.com looks at the risks and side effects of the combination ... Birth Control FAQ – Mayo Clinic Some frequently asked questions and answers about birth control. Marijuana and birth control pills – Ask Alice This short article explains the research and the possible risks of usi... Birth control pills and smoking – Go Ask Alice Whether or not smoking changes the effectiveness or risks of the pill.