If you’ve had an abnormal Pap smear result, your clinician might suggest doing a vinegar test on your cervix. Vinegar tests are also called white spot tests or visual inspection with acetic acid (VIA).

Vinegar or white spot tests typically happen after an abnormal Pap smear result. The test uses vinegar to screen for precancerous or cancerous cells on the cervix.

Read on to learn more about vinegar tests, including what they involve, how to prepare, what to expect afterward, and more.

Doctors use white spot tests to detect precancerous or cancerous cells on the cervix.

Human papillomavirus (HPV) most commonly causes cervical cancer. If HPV test results are positive, or if a clinician detects abnormalities during a routine pelvic exam or Pap smear, they might suggest a vinegar test to screen for cervical cancer.

A white spot test typically occurs during a colposcopy, where a clinician uses a special magnifying device called a colposcope to view the cervix.

Your clinician will apply medical-grade vinegar to your cervix using a cotton swab. They then observe the cervix through a colposcope, which allows them to view the spot. If the spot turns white, it could suggest you have cervical cancer or precancerous cervical cells.

During a colposcopy, the clinician might use iodine instead of vinegar.

According to the American College of Obstetricians and Gynecologists (ACOG), it’s best to have a colposcopy when you’re not menstruating. Try to schedule it for when you won’t have your period.

When you schedule the exam, tell your clinician if you have any allergies or if you are, or think you might be, pregnant.

Ask your clinician if there’s anything they recommend you do to prepare. Some clinicians may recommend you take a mild over-the-counter pain reliever before the exam.

It’s a good idea to bring some menstrual pads with you to the doctor’s office. If you have a biopsy, you might experience some vaginal bleeding afterward.

For at least 24 hours before a colposcopy, ACOG advisesavoiding:

  • douching
  • having penetrative vaginal sex
  • using tampons
  • using any sort of vaginal medication

For your comfort, it’s best that you empty your bowels and bladder before the test.

A colposcopy typically takes around 20 minutes. It usually takes place in a doctor’s or other healthcare professional’s office.

Here’s what you can expect:

  1. During the test, you’ll lie back on an exam table with your legs apart, usually in stirrups, like during a Pap smear or pelvic exam.
  2. Your clinician will insert a speculum into your vagina and gently open it. The speculum is an instrument that holds open your vaginal walls during an exam. This allows your clinician to see your vagina and cervix more easily.
  3. The clinician will apply medical-grade acetic acid (vinegar) to a cotton swab. They’ll dab the cotton swab against your cervix. Although this shouldn’t be particularly painful, it might sting.
  4. For the next few minutes, your clinician will observe your cervix. They might use a swab to examine your cervix more clearly.
  5. If the spot where the vinegar touched your cervix turns white, your clinician will likely take a sample of cells from your cervix to test for cancerous or precancerous cells. This is called a cervical biopsy. This might be painful — you might feel a bit of pressure — but it should be over quickly.
  6. You might bleed after the procedure. Your clinician might use a swab to apply a solution to stop the bleeding.

If you have a biopsy, you might bleed or experience dark discharge after the procedure. You may want to wear a menstrual pad for the next few days or until spotting and discharge stop.

After a cervical biopsy, you might experience some pain and discomfort. Over-the-counter pain relievers can usually manage it.

After a biopsy, your cervix needs to heal. ACOG suggests you avoid putting anything into your vagina — including tampons, douches, and medications — until a clinician says it’s OK to do so.

It is also best to avoid penetrative sex or masturbation until a clinician gives you the all-clear. A biopsy can increase your risk of infection, particularly if you have vaginal sex while it heals.

Consult with a doctor or other healthcare professional as soon as possible if you experience any of the following symptoms:

  • pain, especially in the lower abdomen
  • fever
  • chills
  • heavy vaginal bleeding, or bleeding that soaks through a menstrual pad within an hour
  • foul vaginal odor

When it comes to cervical cancer, early detection can improve your chances of successfully entering remission. For this reason, cervical cancer screening tests, such as the vinegar test, are essential.

If a white spot appears on your cervix after a vinegar test, it’s not necessarily a sure sign you have precancerous cells. A cervical biopsy will determine that.

If you didn’t receive a biopsy during your white spot test or colposcopy and a white spot appears, your clinician will likely recommend that you schedule one.

If you did receive a biopsy during your white spot test or colposcopy, your clinician will tell you when you can expect your biopsy results back.

At that point, they will discuss the next steps with you. If you have a negative result, it means your cervical cells are not cancerous.

Regardless of your results, it’s important to have regular Pap smears. It’s generally best to have a Pap smear once every 3 years if you’re between the ages of 21 and 65.

Your clinician may recommend more frequent Pap smears depending on your individual risk factors.

Is the vinegar test accurate for detecting cervical cancer?

As a 2018 paper points out, the vinegar test is inexpensive, but it’s not always accurate. For this reason, a biopsy should follow a positive vinegar test.

Researchers in a 2022 review looked at four different studies on the vinegar test. They examined whether the vinegar test could prevent deaths related to cervical cancer.

The researchers concluded that the vinegar test seemed to reduce cervical cancer and death in the long run. But more studies are needed before we know how effective it is at preventing invasive cervical cancer.

Although the World Health Organization (WHO) recommends using a vinegar test when more accurate tests are unavailable, there are other emerging ways to test for cervical cancer.

For example, the above-mentioned review notes that HPV testing can be more accurate and helpful than the vinegar test. However, HPV testing can be more costly and labor-intensive than vinegar tests.

The vinegar test, also known as the white spot test, is a cost-effective method for screening cervical cancer.

During a colposcopy, your clinician might apply vinegar to your cervix to test for abnormal cells. If a white spot appears, they will likely perform a biopsy to take a sample

Regardless of the results of your white spot test, it’s a good idea to get regular Pap smears and pelvic exams. These are effective methods of screening for cervical cancer and other gynecological conditions.

Sian Ferguson is a freelance health and cannabis writer based in Cape Town, South Africa. She’s passionate about empowering readers to take care of their mental and physical health through science-based, empathetically delivered information.