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About Bacterial Vaginosis

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What is BV?

  • Bacterial vaginosis (BV) is a common vaginal condition.
  • BV often causes a change in vaginal discharge and smell.
  • BV is not currently considered to be a sexually transmitted infection (STI), but it can sometimes be triggered by sex. It's also possible that bacteria associated with BV may be passed on during sex.
  • BV is usually easy to cure with antibiotics, but some people get it lots of times.

What are the symptoms of BV?

BV is the most common cause of unusual vaginal discharge. Anyone with a vagina can get BV, even if you have never had sex.

BV in women

Half of people with BV don't get any noticeable symptoms.

  • You may notice vaginal discharge that is unusual for you.
  • You may have more discharge than unusual.
  • Discharge may have a strong "fishy" smell, especially after vaginal/frontal sex.
  • Discharge may be thinner than usual and be white or greyish in colour.
  • BV is unlikely to cause soreness, itching or irritation.
  • It's possible to ahve other vaginal infections that do cause irritation - such as thrush - at the same time as having BV.

BV in men

Only people with a vagina can get BV. Experts think that people with a penis can carry bacteria and pass them on to female partners during sex. A recent study showed that treating men with antibiotic tablets and cream reduced recurrences in their female partners - but more research is needed.

BV tests and check-ups

If you have symptoms that might be BV, get checked at a sexual health clinic or GP surgery. They:

  • Will ask about you symptoms.
  • May want to look inside your vagina.
  • May swab inside your vagina to check your vaginal fluid for BV.

Results are often ready straight away for can take up to 2 weeks from a lab.

Some pharmacies sell home BV tests. The accuracy of these can vary, so it's a good idea to get advice on BV from a pharmacist, nurse or doctor.

If you have BV, you may be more likely to get an STI. It's a good idea to get tested for other STIs at the same time as getting check for BV.

You can also get tested for common STIs with a home self-sampling kit from SH.UK.

When to test for STIs.

Test for other sexual health related conditions at home with SH.UK's self-sample test kit

STI test kit

Get a free self-sample test kit delivered to your door. Take a self sample and return via freepost. Access your results online within a week. Check to see if SH.UK offers NHS funded home test kits in your area.


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BV treatment

BV treatment is free from a sexual health clinic or GP surgery. Different treatments include:

  • An antibiotic tablet called metronidazole, taken every day for 5 to 7 days. It may sometimes be given as a single dose instead. Occasionally, a different antibiotic may be offered.
  • Metronidazole gel can be put in the vagina and is used once a day for 7 days.
  • Clindamycin cream can be put in the vagina and is used once a day for 7 days.

Do not drink alcohol while using metronidazole tablets or gel and for 48 hours after finishing treatment.

If you have no symptoms or the BV isn't bothering you, it does not always need treatment as it can go away on its own.

How long does BV last for?

For most people, BV is cured within 4 weeks of starting treatment.

Although BV is not currently considered an STI, it sometimes only clears up when female sexual partners are treated too.

Recurrent BV

Once you have had BV, its common to get it again in the next 3 months. In some people it keeps coming back. This is called recurrent BV. It occurs because many of the BV bacteria stay in the vagina even after treatment and they can trigger the BV to come back.

There are different ways to treat recurrent BV:

  • Antibiotic gel to use regulary for up to 6 months.
  • Antibiotic tablets to use at the start and end of your period.
  • Some people find lactic acid vaginal gel treatments helpful. These are available to buy from a pharmacy or online but are likely to be less effective at treating BV than antibiotics.

Yoghurt and probiotics have not been found to help treat BV or stop it coming back.

Your sexual health clinic or GP can discuss whether it would be helpful for your sexual partner(s) to have treatment too.

Will BV go away on its own?

BV may clear up without treatment.

BV isn't serious for most people, so treatment is only needed of:

  • You have symptoms that are bothering you.
  • You're pregnant and have symptoms.
  • You're having a surgical abortion or other surgery that affects the cervix (entrance to the uterus). Treatment beforehand cna help stop bacteria spreading to the uterus (womb) and causing an infection.

Do I have to tell anyone if I have BV?

BV isn’t considered an STI, so you don’t need to tell current or recent partners or avoid sex unless you want to.

If a sexual partner has a vagina, it can be a good idea if they get checked and treated for BV too. This may help to stop BV coming back.

At the moment, people with a penis are not routinely tested or treated for BV. If you get BV often, it may help if any regular male partners are treated for BV too.

What causes BV?

The vagina is full of bacteria but usually these are the “good” ones called lactobacilli. BV happens when the balance of bacteria in the vagina changes: the lactobacilli decrease and you get an overgrowth of many other bacteria causing the vagina to become less acidic and the discharge to change. Some of these bacteria can produce the unpleasant smell.

It’s not yet known exactly why this happens in some vaginas and not others but it seems to be related to what type of good bacteria you have.

Things that may make BV more likely for some people include:

  • Having a new sexual partner or multiple sexual partners.
  • Douching (rinsing inside the vagina) or using products designed to clean and freshen the vagina. These are unnecessary.
  • Medicated or perfumed soaps, bubble bath, shower gel or strong laundry detergent.
  • Putting antiseptic liquid or disinfectant in the bath.
  • Smoking
  • Receiving oral sex.

Although BV is not considered an STI, it’s possible that BV can be passed from one vagina to another during sex such as through sharing toys.

People with a penis can’t get BV but it may be possible for semen (cum) to affect the balance of bacteria in the vagina and trigger BV. It may also be possible for bacteria associated with BV to be passed on during penis in vagina sex. Using condoms may help.

How can I avoid getting BV?

You can get BV more than once. For some people, it keeps coming back.

It may help to avoid products that can change the balance of bacteria in the vagina, such as medicated, scented or cleaning products.

Wash your vulva with water, using clean hands. Avoid soap if you can and avoid washing inside the vagina.

If you get BV more than twice in 6 months, you may be offered antibiotics to try and stop the BV coming back. A doctor or nurse can also talk to you about possible triggers for BV and may advise having a check-up for STIs and other vaginal infections like thrush.

Is BV serious?

BV is not a serious health problem for most people but it can be distressing and unpleasant.

Having BV can increase the chance of you getting an STI.

If you get BV with symptoms when you’re pregnant, it can increase the likelihood of an early (premature) birth or a miscarriage, so prompt treatment is recommended. BV can safely be treated when you’re pregnant, and most people won’t go on to have any problems.