Bacterial vaginosis (BV) can be treated with antibiotics. If used correctly, treatment is effective in around 9 out of 10 cases.

There is currently no evidence that probiotics, such as those found in live yoghurt, are of any benefit in treating or preventing BV.

Metronidazole

Metronidazole is the most common and preferred antibiotic treatment for BV. It is available in three forms:

• as tablets to be swallowed twice a day for seven days
• as tablets to be taken as a single larger dose that you take only once
• as a gel that you apply to your vagina once a day for five days

The most effective way to take metronidazole is in tablet form over 5-7 days. This is also the preferred treatment if you are pregnant or breastfeeding.

As a precaution, the use of metronidazole (and most other types of medication) is not normally recommended during pregnancy. But an exception is made in the case of BV, as not treating it poses a far bigger risk to the pregnancy than taking the medication.

More women find that their BV is more likely to return if they take the single larger dose. 

Side effects 

Metronidazole can cause nausea, vomiting and a slight metallic taste in your mouth. It is best to take it after eating food. If you start vomiting, contact your GP as the treatment will not be effective.

Do not drink alcohol while taking metronidazole and for at least 48 hours after finishing the course of antibiotics. Drinking alcohol while taking this medicine can cause more severe side effects.

If you cannot tolerate metronidazole, your GP may prescribe a single dose of another antibiotic called tinidazole.

After treatment

If your BV symptoms disappear after treatment, you will not need to be tested for BV again to confirm that the treatment has worked. However, you will need to be tested if:

• your signs and symptoms do not go away
• your signs and symptoms return
• you are treated for BV while you are pregnant

Further treatment

The first course of treatment may not be effective in around 1 in 10 people.

If your treatment has been unsuccessful, your GP will need to check that you took the medicine correctly. If you did and it did not work, you may be prescribed one of the different options described above.

Referral to a specialist

If you have repeated episodes of BV in a short space of time, your GP may recommend that you are referred to a gynaecologist (a specialist in treating conditions of the female reproductive system) for further investigation.

If you are pregnant, you may be referred to an obstetrician (a specialist in pregnancies). They will be able to discuss further treatment options with you. 

Bacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease, and some are good for you.

Inflammation
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Sexually transmitted infections (STIs)
STIs are diseases passed on through intimate sexual contact, such as vaginal, oral or anal sex.

Vagina
The vagina is a tube of muscle that runs from the cervix (the opening of the womb) to the vulva (the external sexual organs).