It is the most effective form of birth control available today. It becomes effective 24 hours from placement. The implant's drug is released over 7 or more years with no need for replacement until the time limit is reached or you desire a pregnancy. At this point the capsules must be surgically removed. Norplant takes the timing and thought out of the birth control.
Many women find it very convenient.
By preventing the normal cycle of hormones that makes an egg form every month. By thickening the mucous at the opening of the womb so the sperm cannot get inside to fertilize the egg. The lining of the uterus becomes thin over time so that a pregnancy cannot implant and periods become light or disappear. Once these implants are removed, you are able to get pregnant in the next cycle. Norplant is not perfect for everyone.