A male condom, also called an external condom, is a thin sheath that fits over the penis during sex to create a physical barrier between partners. It serves two purposes: preventing pregnancy and reducing the risk of sexually transmitted infections. When used correctly every time, it prevents pregnancy 98% of the time over the course of a year. In everyday use, where mistakes like late application or improper removal are common, the failure rate is higher.
How a Condom Works
The concept is simple. The condom catches semen so it never enters a partner’s body. It also prevents direct contact between the skin and mucous membranes of both partners, which is how most STIs spread. This barrier function is what makes condoms unique among contraceptives: they’re one of the only methods that protect against both pregnancy and infection at the same time.
Materials and How They Compare
Most condoms on the market fall into one of four material categories. Each has tradeoffs in terms of feel, durability, and protection.
Latex is the most common and least expensive option. Latex condoms are highly effective against both pregnancy and STIs, and they’re available virtually everywhere. The main drawback is that some people have a latex allergy, which can cause itching and a rash. Latex also breaks down when exposed to oil-based lubricants like petroleum jelly or baby oil.
Polyisoprene is a synthetic rubber designed to feel and stretch like latex without the allergy-triggering proteins. These condoms are just as strong and protect against both pregnancy and STIs. They tend to be slightly thicker than other options, which some people notice.
Polyurethane is a thin, flexible plastic. These condoms are thinner than latex, conduct body heat better, and have no rubber smell. The tradeoff is that polyurethane doesn’t stretch as well, so these condoms may fit more loosely and are slightly more prone to slipping or breaking. They’re harder to find in stores.
Lambskin condoms are made from a thin membrane of lamb intestine. They transmit more sensation and body heat than any synthetic option, and they work with oil-based lubricants. However, the membrane is porous enough to let viruses and bacteria through, so lambskin condoms prevent pregnancy but do not protect against STIs. They’re also the most expensive option.
What Condoms Protect Against
Latex and synthetic condoms are effective at blocking HIV, gonorrhea, and chlamydia. These infections spread through bodily fluids, and a condom keeps those fluids contained.
Protection is less complete for infections that spread through skin-to-skin contact, including HPV (human papillomavirus), genital herpes, and syphilis. These can be transmitted through areas of skin the condom doesn’t cover, like the base of the penis or the surrounding genital area. Condoms still reduce the risk, but they can’t eliminate it entirely for these infections.
Finding the Right Size
Fit matters more than most people realize. A condom that’s too tight is uncomfortable and more likely to break. One that’s too loose can slip off during sex. Condom sizing is based on two measurements: length and nominal width (the width of the condom laid flat).
- Snug fit: roughly 170 to 190 mm long and 49 to 51 mm wide
- Standard fit: roughly 190 mm long and 52 to 53 mm wide
- Large fit: roughly 190 to 226 mm long and 54 to 59 mm wide
Standard condoms work for most people. If you notice frequent slipping, try a snug fit. If a standard condom feels tight or leaves a visible ring on the skin, a larger size will be more comfortable and less likely to tear. Width is generally the more important dimension, since condoms unroll to accommodate different lengths.
How to Use One Correctly
The gap between perfect-use and typical-use effectiveness comes down to technique. Here’s the process that closes that gap:
- Open carefully. Tear the wrapper at the edge. Don’t use teeth or scissors, which can nick the condom.
- Check the direction. The condom should unroll easily away from the tip. If you place it inside-out, discard it and use a new one, since pre-ejaculate may already be on the surface.
- Pinch the tip. Squeeze the air out of the reservoir tip as you place the condom on the head of the erect penis. Trapped air is a common cause of breakage.
- Unroll completely. Roll the condom all the way down to the base of the penis.
- Withdraw promptly. After ejaculation, hold the condom at the base of the penis and pull out while still erect. This prevents the condom from slipping off.
- Dispose of it. Tie the open end, wrap it in tissue, and throw it in the trash. Never flush condoms.
Use a new condom every time, including if you switch between types of sex during the same session. Never double up with two condoms at once. The friction between them actually increases the chance of tearing.
Lubricant Compatibility
If you’re using latex or polyisoprene condoms, stick with water-based or silicone-based lubricants. Water-based options are the safest all-purpose choice. They don’t irritate skin and won’t damage the condom material. Silicone-based lubricants last longer and are also safe with all condom types.
Oil-based products, including petroleum jelly, baby oil, massage oil, and even some hand lotions, break down latex within minutes. This weakens the condom and can cause it to tear during use. The only condoms compatible with oil-based lubricants are polyurethane and lambskin.
Storage and Shelf Life
Condoms have a maximum shelf life of five years under the international manufacturing standard (ISO 4074). That number assumes reasonable storage conditions. Heat, direct sunlight, and friction all degrade the material faster than the expiration date suggests.
Keeping condoms in a wallet, glove compartment, or back pocket exposes them to body heat and friction over time, which weakens the latex before you ever open the wrapper. A cool, dry drawer or bedside table is a better option. Always check the expiration date on the package, and discard any condom that feels brittle, sticky, or stiff when you open it.