Contraception, side effects

• All methods of contraception are associated with fewer health risks than pregnancy and delivery, including overall mortality.
• Especially among adolescents, who generally are healthy, the occurrence of adverse side effects with most forms of contraception is minimal.
• For example, the risk of a thromboembolic event in an otherwise healthy teenager taking oral contraceptives is negligible compared with her risk of developing a complication associated with an unplanned pregnancy, such as pregnancy-induced hypertension.
• Unfortunately, the public misconception is that contraception is dangerous, ineffective, and too costly for most young women to obtain. 
• Condoms and spermicides provide protection against most but not all sexually transmitted diseases: Human papillomavirus and herpes simplex virus still can be acquired if the partner's lesions are located at the base of the penis or on the perineum.
• In addition, condoms may break, and non-latex condoms may allow passage of viral particles (eg, human immunodeficiency virus).
• Oral contraceptives do not affect a woman's risk for breast cancer, an issue that was more controversial in the past.
• Although hair loss occasionally is a side effect of injectable progestin therapy, the most common side effect is a change in menstrual patterns, namely, prolonged and irregular bleeding. 

References:
Brown RT, Cromer BA. The pediatrician and the sexually active
adolescent. Sexual activity and contraception. Pediatr Clin North Am.
1997;44:1379-1390
Stevens-Simon C. Providing effective reproductive health care and
prescribing contraceptives for adolescents. Pediatr Rev.
1998;19:409-417