Why does BV keep coming back?

Recurrence is common, and it is not a sign that anyone did something wrong. The NHS says it is common for bacterial vaginosis to come back, usually within a few months, and the CDC says BV can return even after treatment. The clearest figure comes from a study at a Melbourne sexual health clinic (Bradshaw et al., 2006, Journal of Infectious Diseases) that followed women treated for BV with a standard course of oral antibiotics (139 enrolled): an estimated 58% had BV again within 12 months. Researchers still do not fully understand what causes BV in the first place, which is part of why it can be stubborn.

Partners appear to be part of the story. In the Melbourne study, BV was more likely to return in women who had had BV before, who had the same regular partner throughout, or who had female partners, and the authors concluded this supports a possible role for sexual transmission. In 2025, a trial in the New England Journal of Medicine (Vodstrcil et al.) tested that idea in 164 monogamous couples. When the male partner was treated as well as the woman, BV returned within 12 weeks in 35% of women (24 of 69), compared with 63% (43 of 68) when only the woman was treated.

Guidance has not caught up in one voice. The CDC's BV page, last updated in December 2023, still says male partners do not need treatment, and the trial studied monogamous couples, so it does not tell us what works for people with several partners. If BV keeps returning, ask a clinician whether treating a partner is worth considering. Do not self-treat, and do not use someone else's prescription.

Other factors matter too. The CDC names douching, not using condoms, and new or multiple sex partners as things that upset the vaginal balance. The NHS adds a change of partner, having an IUD, and using perfumed products in or around the vagina, and the Office on Women's Health notes that douching may make it easier to get BV again after treatment. The Melbourne study also found that women using hormonal contraception were less likely to have BV return; that is an association, not proof, and not a reason to change contraception without talking to a clinician.

A clinician has options if BV keeps coming back. The NHS says a recurrence is usually treated again, and someone who gets BV more than four times a year may be offered a longer course of treatment for a few months to help stop it returning. A GP or sexual health clinic can also help identify triggers, such as sex or your period.

Small habits help. The NHS suggests washing the genital area with water and plain soap, taking showers rather than baths, and avoiding perfumed soaps, bubble bath, vaginal washes and douches, antiseptic bath liquids, strong detergents for underwear, and smoking. Condoms may help too: the CDC counts not using condoms among the things that raise BV risk, and the Office on Women's Health suggests protection, including a fresh condom on shared toys, for partners. BV is common and treatable, and telling a partner about it is a health conversation, not a confession. This is general information, not medical advice.