Condoms and other barrier methods

Contact a pharmacist or sexual health service promptly if a condom splits or slips during sex: emergency contraception or an STI test may be needed. Condoms help prevent pregnancy and reduce STI risk; diaphragms and caps do not protect against STIs.

External and internal condoms

An external condom goes over the penis before vaginal, anal or oral sex. It helps prevent pregnancy and reduces the risk of sexually transmitted infections, or STIs. An internal condom is placed inside the vagina; its outer ring stays outside. During sex, the penis needs to go inside the condom, rather than between it and the vaginal wall.

Use a new condom each time and follow its packet instructions. Check the expiry date before opening it. Put an external condom on before the penis touches the vagina or anus, and hold its base while withdrawing after sex to help stop it coming off.

Do not use an internal and external condom together, or layer condoms. The NHS warns that this can make them split. For internal condoms, evidence for STI protection during anal sex is limited; the NHS says they may help, but the amount of protection is uncertain.

Choose lubricant and material together

With latex condoms, use water-based or silicone-based lubricant. Oil-based lubricant is not suitable. Check the material on the packet: latex-free options are available if you have a latex allergy. Some internal condoms also contain latex, so check those too.

Lambskin condoms help prevent pregnancy but may not protect against STIs, including HIV, according to CDC. A latex-free label alone does not tell you how much STI protection a product offers. Check the material and packet information.

If you are using an antifungal medicine around the genitals or anus, ask a pharmacist which barrier is suitable. NHS advice says not to use latex condoms in this situation. Bring the medicine name and condom packaging with you.

What a diaphragm or cap involves

A diaphragm or cap covers the cervix, the entrance to the womb, to stop sperm entering. It goes inside the vagina before sex and needs spermicide. These methods do not protect against STIs. A clinician checks the fit and teaches you how to insert and remove the device.

Follow the instructions for both the device and spermicide, including how long to leave it in after sex and when it must be removed. Check for holes before each use. Ask the clinic to review the fit after giving birth, a miscarriage or an abortion, because a different size may be needed.

Toxic shock syndrome (TSS) is a rare but life-threatening infection that can happen with a diaphragm or cap. Symptoms can develop quickly.

Comparing effectiveness figures

The NHS says external condoms are up to 98% effective when used correctly every time, and 82% effective if not used correctly. Its figures for internal condoms are up to 95% and 79%, respectively. These figures describe pregnancy prevention. They do not measure STI protection.

US estimates differ. The FDA says that, out of 100 women whose partners use external condoms, 13 may get pregnant during a year of use. It describes actual use, including incorrect or inconsistent use. When comparing figures, check who published them and whether they describe correct or actual use.

Getting supplies and help

In the UK, external condoms are free from sexual health clinics and some GP surgeries and pharmacies. In the US, the FDA lists external condoms as available over the counter or online. For a diaphragm or cap, arrange fitting advice with a sexual health clinic or GP in the UK, or your healthcare provider in the US and elsewhere.

Contact a pharmacist, sexual health clinic or GP today in the UK, or a pharmacist or sexual health service in the US and elsewhere, after a condom splits, slips or leaks. Ask for advice too if you discover a hole in a diaphragm or cap after sex. Explain what happened and when.

Call 999 now (UK) or 911 (US), or your local emergency number, for confusion or difficulty breathing.

Get urgent help now from NHS 111 (UK), or an urgent medical service (US and elsewhere), if you develop a high temperature with vomiting, diarrhoea, muscle aches or a rough rash while using a diaphragm or cap. Tell the service that you are using a diaphragm or cap.