Skip to main content

Postexposure Prophylaxis

Medically reviewed by Last updated on Jan 5, 2023.

Postexposure prophylaxis (PEP) is medical care given to prevent HIV, hepatitis B, and other diseases. PEP may include first aid, testing, and medicines. Exposure can occur when you have contact with certain body fluids from another person. These fluids include blood, semen, and vaginal fluid. They also include any other body fluid that may have blood in it, such as saliva or urine. You are exposed if these fluids touch an open area of your skin, such as a cut. You also are exposed if the fluids touch a mucus membrane. This is a moist area, such as in the eyes, nose, and mouth. You can be exposed by a needlestick through the skin.



  • Antiretrovirals: These medicines help prevent HIV. They must be taken for 28 days, unless your healthcare provider tells you otherwise. You may be given a starter pack with enough medicine for 1 to 7 days. You may be given medicine for the full 28 days instead. If you receive a starter pack, you must return to your healthcare provider in 1 to 7 days. At this visit, you will receive the rest of the medicine.
  • Hepatitis B vaccine: This medicine helps prevent hepatitis B. You will need 3 doses (shots) of the vaccine. The second dose should be taken 1 to 2 months after the first dose. The third dose should be taken 4 to 6 months after the first dose.
  • Antibiotics: These are germ-killing medicines to help treat or prevent sexually transmitted diseases, such as gonorrhea.
  • Take your medicine as directed. Contact your healthcare provider if you think your medicine is not helping or if you have side effects. Tell your provider if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.

Follow up with your healthcare provider as directed:

If you did not receive any treatment after the exposure, you will need to follow up with your healthcare provider within 1 week. If you were given antiretrovirals, you will need a follow-up visit in about 2 weeks. Further HIV testing will be needed 6 weeks, 3 months, and 6 months after the exposure. You may have HIV testing up to 12 months after the exposure.


In case you are infected, you will need to take steps to keep others from getting sick. These steps can help you avoid being exposed again:

  • Avoid sex, or have safe sex. Safe sex means having sex only with one person who is not infected and who is only having sex with you. It also means using condoms each time you have sex.
  • Avoid injection drug use. If you cannot do this, always use needles that are sterile (germ-free).
  • Follow all safety rules at your workplace if you are at risk of exposure. Be sure to use safety equipment as needed.
  • Get the hepatitis B vaccine if you have not already.
  • Do not breastfeed unless you know you are not infected.

In case of future exposure:

If you think you have been exposed, get first aid right away. If you are at work, follow work policy to report the exposure. The type of first aid you need depends on what part of your body was exposed:

  • Open skin: Wash the area right away with soap and water. Use a gel hand cleaner if you do not have soap or running water. Do not use anything harsh, such as bleach. Do not squeeze or rub the skin.
  • Eyes: Rinse your eyes with water or saline (a salt solution) right away. Be sure to clean well by moving your eyelids with your fingers as you rinse. Keep contact lenses in while rinsing your eyes, then remove and clean them as usual. Avoid soap or other cleaners.
  • Mouth: Spit out the blood or body fluid right away. Rinse your mouth with water or saline several times. Avoid putting soap or other cleaners in your mouth.

For support and more information:

It can be hard to cope if you think you have been exposed to a disease. You may feel scared and concerned about your health. This is normal. It can be helpful to find out all you can about the risk of exposure. Counseling or joining a support group also can help. Talk to your healthcare provider, or contact the following:

  • National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC
    Web Address:
  • The National Clinicians' Post-Exposure Prophylaxis Hotline
    Web Address:

Contact your healthcare provider if:

  • You have nausea or diarrhea.
  • You are more tired than usual.
  • You have new headaches, or you feel dizzy.
  • You have trouble sleeping.
  • Your eyes or skin turn yellow.
  • You are not eating because of appetite loss.
  • You are or may be pregnant.

Return to the emergency department if:

  • You have a fever.
  • You have a rash.
  • You have new muscle pain or pain in your back or abdomen.
  • You urinate more often than usual, have blood in your urine, or have pain while urinating.
  • You are more thirsty than usual.
  • You have trouble swallowing or breathing.

© Copyright Merative 2022 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.