- Oral contraceptives for men are in development
- Japanese researchers have made mice reversibly infertile
- Also being trialled are injections that block sperm from leaving a man's body
Vital Signs is a monthly program bringing viewers health stories from around the world.
(CNN)"The Pill" -- two words synonymous with birth control. But more than 50 years after oral contraceptives became commonplace, they remain an option only available to women.