The Incubation Period of Common STIs

An incubation period is the length of time between when you are infected with bacteria or a virus and when symptoms appear. Knowing how long the incubation periods are for sexually transmitted infections (STIs) can help you figure out if you have one. It can also help you know when you should see a healthcare provider.

This article will help you understand how long it usually takes for symptoms of specific STIs to show up after exposure. In some cases, it may be a lot longer than you think.

Illustrated chart of incubation periods for common STDs


How Long Before STI Symptoms Appear?

The time between exposure to an STI and when you start having symptoms depends on the disease you were exposed to. Here are the most common STIs and their incubation periods.


Many people never have any symptoms of chlamydia. This is an extremely common STI caused by the bacterium Chlamydia trachomatis.

When symptoms do appear, they are usually not noticeable for several weeks after exposure to the infection.

Even without symptoms, people with chlamydia can have complications. So, it is crucial to get screened for this STI regularly.


Gonorrhea is caused by the Neisseria gonorrhoeae bacterium. It is frequently asymptomatic (it has no symptoms).

When symptoms appear, they may show up as early as one day after exposure or take as long as two weeks.


Syphilis is a bacterial infection caused by a bacterium called Treponema pallidum. Syphilis initially causes an ulcer (open sore) on the genitals. This appears an average of 21 days after infection.

However, the ulcer may occur anytime between 10 and 90 days after exposure to the bacterium.


Genital ulcers associated with chancroid are caused by the Haemophilus ducreyi bacterium.

This STI is rare in the United States, but when it does occur, the lesions usually appear within four to 10 days after exposure.


Although penile symptoms of trichomoniasis (“trich”) can be mild or asymptomatic, vaginal symptoms usually appear five to 28 days after exposure.

Trich is caused by the Trichomonas vaginalis parasite.


Scabies is caused by the parasitic mite Sarcoptes scabiei. The female mite burrows under the skin and lays two or three eggs a day. She keeps burrowing and laying eggs for the rest of her life, usually a month or two. When the larvae hatch, they cause an itchy rash.

If you’ve never had scabies before, it may take two to six months for symptoms to appear. If you were previously infected, symptoms may show up after one to four days.

Genital Warts

Genital warts are caused by a strain of the human papillomavirus (HPV).

Symptomatic HPV has a very long incubation period, so it may be months or years before genital warts appear.

Genital Herpes

Most people never know they’re infected with genital herpes, caused by the herpes simplex virus.

When it is symptomatic, it causes lesions on the genitals. These usually show up two to 12 days after exposure to the virus. Some people will also experience a fever and full-body viral symptoms around the same time.

Human Immunodeficiency Virus (HIV)

Most people who are infected with HIV remain asymptomatic for years. Some people will get a fever and flu-like symptoms around two weeks after exposure. However, most people do not recognize these as symptoms of HIV.

The only way to know if you have HIV is through testing. Most people will test positive on an antibody test within three weeks to three months of exposure. Therefore, a negative test isn’t a reliable indicator of your infection status if you were only exposed a week before.

An antigen/antibody test can detect infection in 18–45 days after exposure if it’s done with blood directly from a vein. If it’s done with blood from a finger prick, it might take up to 90 days.

A nucleic acid test can detect infection earlier—within 10–33 days—but those tests are very expensive, so they’re not used for routine screening.

Hepatitis B

Symptoms of the hepatitis B virus usually show up between two to five months after infection and can range from mild flu-like symptoms to more severe conditions like jaundice and liver disease.

Molluscum Contagiosum

Scientists are uncertain about the incubation period of the molluscum contagiosum virus, which causes small, raised, fluid-filled bumps on the skin. Current estimates range from two weeks to six months.

If you think you may have had exposure to any STIs, you should get tested right away.

Asymptomatic STIs Are Common

It’s essential to keep in mind that waiting for symptoms to show up is not a good way to know whether you or your partner(s) have an STI. Many sexually transmitted infections can remain asymptomatic for years. In other words, you could have an STI but no noticeable signs of infection.

Furthermore, someone can have no STI symptoms at all and still be contagious.

Examples of STIs that may remain asymptomatic for a long time include:

  • Gonorrhea
  • Chlamydia
  • Herpes
  • HIV
  • HPV
  • Trichomoniasis

A lack of symptoms is no guarantee that you don’t have an STI. You may be infected and able to transmit the disease to your sexual partners. That’s why there’s no substitute for regular screening.

How STIs Are Diagnosed

Doctors diagnose different STIs in different ways.

For example, urine tests can detect gonorrhea and chlamydia, whereas blood tests detect syphilis, herpes, and HIV. Testing for other infections requires genital swabs.

Types of STI Tests
Infection Test
Chlamydia Urine test or swab
Gonorrhea Urine test or swab
Syphilis Blood test
Chancroid Swab
Trichomoniasis Urine test or swab
Scabies Physical exam or skin scrape
Genital warts (HPV) Swab
Genital herpes Swab
HIV Blood test or swab
Hepatitis B Blood test
Molluscum contagiosum Physical exam

When to Get Tested

The timing of testing depends on which STI you may have been exposed to. Generally speaking, a good recommendation is two to three weeks after exposure or when you notice symptoms.

However, some infections can't be accurately detected for months. Knowing which STI you came in contact with will make it easier to understand when testing will be most accurate.

Incubation Periods
Infection Incubation Period
Chlamydia Several weeks
Gonorrhea 1–14 days
Syphilis 10–90 days
Chancroid 4-10 days
Trichomoniasis 5–28 days
Scabies 1 day–6 months
Genital warts (HPV) Several months–several years
Genital Herpes 2–12 days
HIV Several years
Hepatitis B 2–5 months
Molluscum contagiosum 2 weeks–6 months

Reasons to Get Tested

It’s also worth noting that concerns about STI incubation periods aren’t just for people who have unprotected sex. Although practicing safer sex can drastically reduce your risk, it isn’t foolproof protection.

Condoms and other barriers can reduce the risk of diseases, but they can’t entirely prevent them. That’s why it’s a good idea to talk about testing and risk potential with new partners before you have sex.


The incubation period of STIs depends on which one you were exposed to. The time from exposure to when symptoms appear can range from a few days to as long as six months.

In addition, some STIs may not cause symptoms at all. That means you may be infected but be unaware of it. That’s why regular STI testing is essential.

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14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Centers for Disease Control and Prevention. Gonorrhea – CDC fact sheet (detailed).

  3. Centers for Disease Control and Prevention. Syphilis – CDC fact sheet (detailed).

  4. Centers for Disease Control and Prevention. Chancroid.

  5. Centers for Disease Control and Prevention. Trichomoniasis – CDC fact sheet.

  6. Centers for Disease Control and Prevention. Scabies - biology.

  7. Centers for Disease Control and Prevention. Scabies.

  8. Centers for Disease Control and Prevention. Genital HPV infection – fact sheet.

  9. Centers for Disease Control and Prevention. Genital herpes – CDC fact sheet (detailed).

  10. Centers for Disease Control and Prevention. About HIV.

  11. Centers for Disease Control and Prevention. Types of HIV tests.

  12. Centers for Disease Control and Prevention. Hepatitis B questions and answers for health professionals.

  13. Centers for Disease Control and Prevention. Molluscum contagiosum - clinical information.

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