Search the herb "saw palmetto" on the web. Saw Palmetto is a herb that works against male pattern baldness, and it protects the prostate. It does not have any side effects. Saw Palmetto does not actually include any hormones like prescription drugs, so it is much much safer and natural.
Saw Palmetto extracts are sold by many companies in capsule form. Look for a quality brand when buying. The brand SOLGAR seems to be my favorite for this reason.