Gandarusa is a leafy plant that has been used by Indonesians for centuries to relieve stress. Recently researchers have also tried to harness its other side effect: reduced male fertility.
One of the main problems with oral contraceptives is that they alter a person's hormonal balance, causing such negative side effects as weight gain, reduced libido, and mood swings. However, the chemical found in Gandarusa does not interfere with a person's hormones. Rather, the chemical disarms sperm, making them unable to penetrate the egg.