STI Prevention

If you are sexually active, you can reduce your risk of getting an STI. Some of the things you can do are listed below. However, the only 100% sure way to prevent STIs is to not have sex, including oral sex.

  • Condoms
  • Knowing the signs of STIs
  • Healthy relationships
  • Engaging in health care
  • Considering DoxyPEP

Condoms

STIs can be passed through bodily fluids between people when they have sex, such as semen, vaginal fluids, and blood. Some STIs, like genital herpes, can be passed through genital-to-genital contact or skin-to-skin contact.

People can use condoms, a dental dam, or an internal condom to stop bodily fluids from moving from the body of one person to another. When you use condoms correctly every time you have sex, they provide protection from bodily fluids and genital-to-genital contact. That’s how they help prevent STIs.

Remember:

Know the Signs

Sometimes, STIs don’t have immediate signs or symptoms, which makes it hard to tell if you have an STI unless you get tested. It’s important to know common symptoms of STIs so you can tell your medical provider what you’re experiencing.

Common symptoms of STIs might be:

  • Burning when you pee
  • Having to pee frequently
  • Cloudy discharge (discharge can come from a vagina or from a penis, and you might see it on your underwear – it’s not the same thing as semen, menstrual blood, or urine)
  • Itching in genital areas
  • Sores (might look like a small injury that has not scabbed over)
  • Skin rashes or redness
  • Pain or discomfort during sex

For a full list of symptoms for each STI, go to teensource.org.

If you’re experiencing any of these symptoms or you had unprotected sex recently, contact your medical provider about this or use the Where to get tested feature on this website to find an STI testing location.

Healthy Relationships

If you’re having sex with someone you trust and has shown they are respectful toward you, it will probably be easier to talk about sex. That might sound awkward, but it’s important if you want to start using condoms, or if you have concerns about your health that you decide to share.

Engaging in Health Care

If you can see a medical provider that you trust, they can give good advice about taking care of your sexual health, as well as your general health overall.

Having a medical provider that you can see for lots of different concerns is called a primary care provider. Your primary care provider might be a nurse practitioner or a doctor, and they can usually provide STI testing. You can use the Where to get tested feature if you don’t have a primary care provider or you’re not sure where to go for STI testing.

Consider DoxyPEP

DoxyPEP is a tool to protect yourself against certain sexually transmitted infections (STIs) – syphilis, chlamydia, and gonorrhea. Think of doxyPEP as a morning-after pill (or Plan B), but it works for preventing these STIs instead of preventing pregnancy. Take one dose after a condomless sexual encounter to greatly reduce your risk of getting those STIs.

If you take doxyPEP, just remember that it’s 3, 2, 1!

Within 3 Days, Take 2 Tabs, Just 1 Time

Howard Brown Health. DoxyPEP for STI Prevention. Services; Sexual & Reproductive Health. Source. Accessed 05/13/2025.

In other words:

  • Within 3 days, or 72 hours, of a condomless sexual encounter
  • Take 2 tablets, or 200 mg, of doxycycline
  • Just 1 time, or no more than one dose per day

When taking doxyPEP, you should also keep in mind that:

  • Although doxycycline has many alternate uses, you should only take doxyPEP as prescribed for you and not someone else
  • It will be most effective if you take it within the first 24 hours
  • Although it is safe to take daily, do not take more than 200mg in one day
  • Take it with 8 oz of non-alcoholic beverage and food to help decrease potential side effects like nausea or headache
  • Some people are more sensitive to the sun when they take it, so wear sunscreen and stay covered when spending extended time outdoors

Before starting doxyPEP you should know that:

  • If you’re taking medication to treat or prevent HIV, it is safe to take doxyPEP at the same time
  • DoxyPEP treatment is not 100% protective, so you should still see your medical provider regularly to get tested for STIs
  • Since this treatment method is relatively new, we are still learning about the effects of doxyPEP on the ‘good’ bacteria of the gut, the bacteria that live on our skin (such as staph), and possible medication resistance of STIs such as gonorrhea
  • Doxycycline is not a new medication – it has long been used as a common antibiotic due to its safety, mild potential side effects, and low cost