Do vaginal probiotics work?

There are probiotics for vaginal health everywhere: capsules, pessaries and gummies, many sold as "pH balancing". Some have real evidence behind them, and many don't. A 2026 review pulled together the research on probiotics for bacterial vaginosis (BV) and thrush, and this is what it found.

What are vaginal probiotics?

They're live bacteria, usually types of Lactobacillus, taken by mouth or put into the vagina as a pessary or capsule. The idea is to top up the Lactobacillus that normally keeps the vagina acidic. For how that works, see Vaginal pH balance: what's normal, what upsets it and how to keep it balanced.

Do probiotics help BV?

Not on their own. The review found that probiotics don't work as a treatment for BV by themselves; antibiotics are still the treatment. Where they may help is in stopping BV coming back, which is common: up to 30% of people get it again within three months.

The strongest evidence is for one strain, Lactobacillus crispatus, put into the vagina after a course of antibiotics. In the main trial, BV came back in 30% of women using it after 12 weeks, compared with 45% on placebo, and the benefit faded after three to six months. Oral probiotics, including most supplements sold as "pH balancing", had smaller and less consistent effects.

Which probiotics are good for vaginal health?

Vaginal probiotic pessaries are on sale in the UK, but most contain other strains, such as Lactobacillus acidophilus, which have weaker evidence. Some also contain extras such as garlic or essential oils, which can irritate the vagina and vulva, so check the ingredients and avoid anything fragranced. A pessary can be tested for quality and safety without being tested to see whether it works.

If you have recurrent BV and want to try one, use it alongside treatment rather than instead of it, and talk to your GP or sexual health clinic. The NHS page on bacterial vaginosis explains diagnosis and treatment.

Do probiotics help thrush?

The review found no convincing evidence that probiotics treat thrush or stop it coming back. There may be a small short-term benefit when they're used alongside antifungal treatment, but the evidence is low quality. Researchers are also looking at probiotic yeasts for thrush, but so far there are only small studies, mostly funded by manufacturers.

Do I need a probiotic if I don't have symptoms?

There's no evidence that you do. A healthy vagina looks after its own balance. If something changes, such as a new smell, different discharge, itching or soreness, get it checked rather than reaching for a probiotic, because BV, thrush and some sexually transmitted infections need different treatments.

References

Claassen-Weitz S, Happel A-U, "Probiotics for BV and VVC Treatment and Prevention: An Umbrella Review of Systematic Reviews and Meta-Analyses, with Inclusion of Recent Randomized Controlled Trials," Current Obstetrics and Gynecology Reports (September 2026) https://link.springer.com/article/10.1007/s13669-026-00491-z

NHS, "Bacterial vaginosis," (reviewed June 2026) https://www.nhs.uk/conditions/bacterial-vaginosis/