Bacterial vaginosis (BV) is cured with antibiotics, typically a 5- to 7-day course that clears symptoms within a few days. But here’s the challenge: within 6 to 12 months of finishing antibiotics, 50% to 80% of women experience a recurrence. So curing BV isn’t just about the first round of treatment. It’s about understanding why it happens and what keeps it from coming back.
What’s Actually Happening in Your Body
Your vagina naturally hosts a community of bacteria dominated by Lactobacillus, a type of bacteria that produces acid and keeps the vaginal pH low (around 3.8 to 4.5). This acidic environment prevents harmful bacteria from gaining a foothold. BV happens when Lactobacillus populations crash and get replaced by an overgrowth of anaerobic bacteria, organisms that thrive without oxygen. The main culprits include Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis, and Prevotella, among others.
What triggers this shift isn’t fully understood. But once the protective bacteria are gone, vaginal pH rises above 4.5, creating conditions that favor the overgrowth and make it self-sustaining. That’s why BV doesn’t resolve on its own for most people and why treatment targets these anaerobic bacteria specifically.
How BV Is Diagnosed
A clinician diagnoses BV by looking for at least three of these four signs: a thin, milklike discharge that coats the vaginal walls; a vaginal pH above 4.5; a fishy odor (especially noticeable after sex or when the discharge is tested in the office); and “clue cells” visible under a microscope, which are vaginal cells covered in bacteria. You can suspect BV based on the discharge and odor alone, but a confirmed diagnosis requires a clinical exam.
Antibiotic Treatment Options
The standard treatment is a course of one of two antibiotics: metronidazole or clindamycin. Both are available as oral pills or vaginal gels/creams. The oral and vaginal forms work similarly well, so the choice often comes down to preference and side effects. Oral metronidazole can cause nausea and a metallic taste, and you need to avoid alcohol during treatment and for a couple of days after. The vaginal gel avoids those systemic side effects but requires inserting the medication for several consecutive nights.
If you want a faster option, a single-dose oral treatment called secnidazole exists. You take one packet of granules mixed into food, and that’s it. The trade-off is efficacy: in clinical trials of 352 women, about 50% achieved a clinical cure after a single dose, compared to 20% on placebo. That’s a meaningful effect, but the cure rate is lower than a full week of metronidazole. It’s a reasonable choice when convenience is a priority or adherence to a multi-day regimen is a concern.
Why BV Keeps Coming Back
The recurrence rate is the most frustrating part of BV. Half to four-fifths of women will have another episode within a year of treatment. Antibiotics kill the overgrown bacteria, but they don’t necessarily restore a healthy Lactobacillus population. If the vaginal ecosystem doesn’t fully recover, conditions remain favorable for the same anaerobic bacteria to return.
Sexual activity plays a bigger role than previously thought. For years, treating male sexual partners wasn’t recommended because the evidence wasn’t strong enough. That changed recently. The American College of Obstetricians and Gynecologists now recommends considering concurrent treatment of male sexual partners for women with recurrent BV, based on growing evidence that bacteria associated with BV can be carried and transmitted by male partners. This is a significant shift. If you’re dealing with repeated episodes, ask your clinician about partner treatment with a combination of oral and topical antimicrobials.
Probiotics and Restoring Vaginal Flora
Because the core problem is a depleted Lactobacillus population, there’s been significant interest in whether probiotics can help. The most studied strain for vaginal health is Lactobacillus rhamnosus GR-1, often combined with Lactobacillus reuteri RC-14 (previously classified as L. fermentum RC-14). In a randomized, placebo-controlled trial of 64 healthy women, oral use of these two strains significantly altered vaginal flora in a favorable direction.
Probiotics are not a replacement for antibiotics during an active infection. But taking them alongside or after antibiotic treatment may help rebuild the protective bacterial community and reduce the chance of recurrence. Look for supplements that specifically list these strains rather than general “women’s health” probiotics with unrelated bacteria. The research is promising but not yet definitive enough to call probiotics a guaranteed prevention strategy.
Habits That Help and Hurt
Douching is one of the clearest risk factors for BV. Women who douche at least once a month have a 1.4 times higher risk of developing BV or disrupted vaginal flora. Douching within the prior week more than doubles the risk. The mechanism is straightforward: douching washes away the hydrogen peroxide-producing Lactobacillus that protect against overgrowth, essentially creating the exact conditions that lead to BV. If you currently douche, stopping is one of the most impactful things you can do.
Other practices that support vaginal health are less dramatic but still matter. Wearing breathable cotton underwear, avoiding scented soaps or sprays near the vaginal area, and wiping front to back all help maintain the environment your protective bacteria need. New sexual partners and unprotected sex are also associated with higher BV risk, likely because they introduce different bacterial communities that can disrupt the existing balance.
BV During Pregnancy
If you’re pregnant, BV carries specific risks. It increases the chance of preterm birth and low birth weight (a baby weighing less than 5.5 pounds). These are serious enough that treatment during pregnancy is recommended even for women who might otherwise take a wait-and-see approach. Your prenatal care provider can test for BV and prescribe pregnancy-safe antibiotics if needed.
What a Realistic Treatment Plan Looks Like
For a first episode, a standard antibiotic course will likely clear your symptoms within a few days. Finish the full course even if you feel better early. For recurrent BV, the approach gets more layered: antibiotics to treat the active infection, possible extended or suppressive antibiotic therapy to prevent recurrence, partner treatment if you have a regular male sexual partner, probiotics as an adjunct, and elimination of douching or irritating products.
No single intervention is a silver bullet, especially for recurrent cases. The combination of killing the overgrown bacteria, rebuilding your Lactobacillus population, reducing reintroduction from partners, and avoiding practices that destabilize vaginal pH gives you the best odds of staying BV-free long term.