Two forms of contraception not included in the chart are tubal ligation and vasectomy. Since those methods are very hard to reverse, they should only be considered by persons who have completed their families. Over the counter contraceptives all work as a barrier of some sort-to keep the sperm from fertilizing an egg. Spermicides work by killing the sperm before it fertilizes the egg. Male condoms keep the sperm from entering the vagina.
Female condoms collect the sperm that has entered the vagina.
There are new products currently being tested that will prevent conception and help prevent STD's. Called microbicides, these act by killing not only the viruses that cause STD's, but also as a spermicide. These products are still being researched, but may be on the market by the year 2002. One thing that is vital to remember-any method used after intercourse is too late.