What is a condom?
The United States Food and Drug Administration regulates condoms as a Class II medical device. Per the FDA,,"A condom is a sheath which completely covers the penis with a closely fitting membrane. The condom is used for contraceptive and for prophylactic purposes (preventing transmission of sexually transmitted infections). The device may also be used to collect semen to aid in the diagnosis of infertility."
What are they made of?
Polyisoprene is a synthetic version of a material derived from the sap of the hevea tree and contains no latex proteins, but is as strong and safe as latex. Polyisoprene condoms are not as thin as polyurethane, but they are stretchy and have a lower breakage and slippage rates.
Polyurethane conducts heat better than latex (so may not be as noticeable). Polyurethane condoms also are thinner than most latex condoms, and they have little to no smell. However, polyurethane doesn’t stretch like latex or polyisoprene, so slippage and breakage rates are higher. You should NOT use additional lubricant with a Polyurethane condom.
Lambskin - natural animal membrane. People who use these condoms particularly like the feel of the natural membrane. There are several drawbacks to these condoms. First, they do not provide protection against STDs. They are only considered to be effective as prevention against unwanted pregnancy. Second, the natural skin condoms are extremely expensive. Lastly, natural skin condoms have a unique and some say barnyard smell
Comparison of Contraceptive Effectiveness: