Can you give yourself an STI?

This blog first appeared on 19/05/2023. Last updated 07/03/2025.

Very rarely, the odd person might wake up one day to strange symptoms they’ve never experienced before. They get tested and realise that they’ve got an STI.

But they never had sex. So, what’s going on?

While people can’t get infected with a sexually transmitted infection (STI) out of the blue, it’s possible to get one without having sex, and there are some rare instances where you can “give yourself” an STI.

How does this happen? To understand, we need to explain how STIs are transmitted and detail all the non-sexual ways you can get an STI, from using contaminated household items to transferring an infection to another part of your body.

Keep reading to find out more.

An STI can harm your sexual health if left untreated. Book an STI at a sexual health clinic near you.

How STIs are transmitted

You probably know that most people get sexually transmitted infections through sexual contact.

“Sexual contact” is a fairly nebulous term, but it can include forms of sexual intercourse like oral, anal, or vaginal sex, as well as genital-to-genital and skin-to-skin contact that don’t involve penetration.

Anytime infected bodily fluids like semen, blood, vaginal fluids, or pre-ejaculate come into contact with another person’s mucous membranes or broken skin, there is a risk of an infection being passed on.

You can also become infected with infections like Syphilis or Human Papillomavirus (HPV) by touching a chancre or wart.

Ways you can “give yourself” an STI

With all that said, it’s indeed possible to “give yourself” an STI, so to speak. There are many STIs that can be transmitted without sexual contact with a partner.

Let’s go through some of the ways this can happen.

Using contaminated needles, razors, and toothbrushes

Using contaminated needles is another way you can potentially give yourself an STI.

Needles are commonly used for medical procedures, drug use, and tattoos. If they’re not properly sterilised before use, there is a risk of exposure to blood-borne infections such as Human Immunodeficiency Virus (HIV), or Hepatitis B, or Hepatitis C.

If you come into contact with someone else’s infected blood by sharing a needle, then there is a chance that you may be infected. Therefore, it’s important to always practice safe injection practices when using needles and ensure that any equipment used has been properly sterilised beforehand to reduce exposure risk.

Healthcare workers are often at risk of blood-to-blood exposure through needle-stick injuries.

You can also contract STIs like Hepatitis B by sharing toothbrushes, razors, and similar household items that may break the skin.

Transferring an infection from one part of the body to another

It’s possible to transfer an STI from one part of your body to another, even if you don’t come into direct contact with someone else.

While some STIs are whole-body infections, others are more site-specific.

This can occur with infections like Gonorrhoea and Chlamydia. If, for example, you have a Gonorrhoea infection in your genitals, masturbate, and immediately touch your eye, you can transfer the infection from your genitals to your eye.

More commonly, in the case of Gonorrhoea or Chlamydia, an infection in the penis or vagina can be passed into the patient’s rectum through contaminated sex toys or masturbation.

Transference of vaginal infections of Chlamydia into the rectum can also happen just because of proximity and wiping while on the toilet. It’s estimated that some 80% of women positive for Chlamydia in a vaginal sample will also have the infection rectally despite not ever having anal sex.

There is also some evidence to suggest that vaginal yeast infections and Bacterial Vaginosis (BV) can be passed by masturbating a partner’s vagina with saliva. However, it’s not entirely clear if the fungus is physically passed on or if other factors affect the balance of flora within the vagina. Mutual masturbation has also been highlighted as a potential risk factor for younger women.

Final thoughts

Recognising the potential risks of STI transmission and taking appropriate steps to protect yourself is important. By using safe injection practices, avoiding contact with infected body fluids, and properly cleaning any sex toys or equipment, you can significantly reduce your risk of self-infection.

If you are sexually active, it’s also a good idea to get tested regularly. Better2Know provides private testing services that allow you to quickly and discreetly find out if you have an infection.

Don’t put your sexual health at risk. Get tested with Better2Know.

This article was medically reviewed by Dr. Steve Chapman, 16/07/2025.