If you're sick, just grin and Bayer it. The health care products subsidiary of Bayer AG, Bayer HealthCare develops and manufactures products for humans and animals. Bayer HealthCare operates through three divisions: Pharmaceuticals, Animal Health (veterinary drugs), and Medical Care (diagnostic equipment makers including Diabetes Care and Bayer Radiology and Interventional). Bayer HealthCare's better-known products include YAZ birth control pills, multiple sclerosis drug Betaseron, and erectile dysfunction treatment Levitra, as well as Bayer Aspirin, Alka-Seltzer, One-A-Day vitamins, and the flea preventative Advantage.