Condoms are a form of barrier birth control, and they come in many varieties. Some condoms come coated with spermicide, which is a type of chemical. The spermicide most often used on condoms is nonoxynol-9.

When used perfectly, condoms can protect against pregnancy 98 percent of the time. There is no current data indicating that condoms coated with spermicide are more effective at protecting against pregnancy than those without.

Spermicide condoms also do not increase protection against sexually transmitted diseases, and they may actually increase the possibility of contracting HIV when having sexual intercourse with someone who already has the disease.

Spermicides, such as nonoxynol-9, are a type of birth control. They work by killing sperm and blocking the cervix. This stops the sperm ejaculated in semen from swimming toward an egg. Spermicides are available in various forms, including:

  • condoms
  • gels
  • films
  • foams
  • creams
  • suppositories

They can be used alone or in conjunction with other types of birth control, such as a cervical cap or diaphragm.

Spermicides do not protect against sexually transmitted diseases (STDs). When used alone, spermicides are among the least effective methods of birth control available, with 28 percent of those sexual encounters resulting in pregnancy.

Spermicide condoms have many positive features. They are:

  • affordable
  • portable and lightweight
  • available without a prescription
  • protective against unwanted pregnancy when used correctly

When deciding whether to use a condom with spermicide or one without, it’s important to also understand the cons and risks. Spermicidal condoms:

  • are more expensive than other types of lubricated condoms
  • have a shorter shelf life
  • are no more effective at protecting against STDs than regular condoms
  • may increase risk for HIV transmission
  • contain a small amount of spermicide compared to other forms of spermicidal birth control

The spermicide used on spermicidal condoms, nonoxynol-9, can cause allergic reactions in some people as well. Symptoms include temporary itching, redness, and swelling. It can also cause urinary tract infections in some women.

Because spermicide can irritate the penis and vagina, contraceptives containing nonoxynol-9 may increase the risk of HIV transmission. This risk increases if spermicide is used multiple times in one day or for several consecutive days.

If you experience irritation, discomfort, or an allergic reaction, changing brands may help. It may also make sense to try other forms of birth control. If you or your partner is HIV positive, spermicidal condoms may not be the best birth control method for you.

Read more: Which birth control is right for you? »

Spermicides probably don’t cause birth defects. If you conceived while using spermicidal condoms or any other type of spermicidal birth control, the fetus will not be harmed as a result.

Spermicides don’t enter breastmilk, either, or affect the production of breastmilk, so they are safe to use while breastfeeding.

No one type of birth control, other than abstinence, is 100 percent effective at preventing unwanted pregnancy or the spread of STDs. Some types are more effective than others, however. For example, female birth control pills are 99 percent effective when taken perfectly, although this rate goes down if you miss a dose. If you prefer a form of hormonal birth control that you don’t have to remember to use daily, talk to your doctor about the following methods:

Other forms of contraception that are not as effective include:

Male and female condoms are the only type of birth control that also helps to prevent STDs. Either one can be used alone or in conjunction with other forms of birth control, such as spermicide.

Every type of birth control method has pros and cons. Your lifestyle habits, such as smoking, your body mass index, and health history, are all important factors you should consider when choosing a method. You can discuss all of these birth control options with your doctor and determine which method makes the most sense for you.

Spermicidal condoms are not shown to have greater benefit than regular condoms. They are more expensive than condoms without spermicide and do not have as long a shelf life. They may also increase the risk of HIV transmission. When used correctly, they may help to prevent unwanted pregnancy.