The implant system consists of small capsules made of plastic tubing, which are filled with a synthetic Progestin. It works just like the pill and the shot by thickening cervical mucus and changing the endometrium. They can provide contraception for up to five years. However, they offer no protection against STD's.
The Progestin implant is highly effective, coming in at a solid 99.96% effectiveness; this is the most effective birth control method available.
The capsules are inserted just under the skin on the inner side of a woman's upper arm. This involves a minor surgical procedure which is obviously only to be done by a qualified medical practitioner.
Any time that hormones are introduced into the body there is the potential for adverse effects. Heavier flow, increased cramping and spotting between periods are all possible side effects whenever hormone levels are changed. These will usually abate after a few months of use.
The implant has the same drawbacks as the pill since it uses the same method of contraception. Please see The Pill page for information on drawbacks.
It offers no protection against STDs.