Bacterial vaginosis clears up with a course of prescription antibiotics, typically taken for five to seven days. BV is the most common vaginal infection in women of reproductive age, and while it sometimes resolves on its own, treatment significantly lowers the risk of complications and persistent symptoms. The tricky part isn’t the initial cure. It’s keeping BV from coming back, which happens in roughly half of treated cases within several months.
Recognizing BV Symptoms
The hallmark of BV is a thin, grayish-white discharge with a noticeable fishy smell, especially after sex. The discharge tends to have a milklike consistency that coats the vaginal walls evenly. Some people also experience mild itching or burning during urination, though many have no symptoms at all.
BV is not a yeast infection. If your discharge is thick, white, and clumpy (like cottage cheese), that points toward yeast. BV discharge is thinner, and the odor is usually the most prominent feature. Getting the right diagnosis matters because the treatments are completely different, and using over-the-counter yeast medication for BV won’t help.
What Causes It
Your vagina naturally contains a mix of bacteria, with helpful species (primarily lactobacilli) keeping the environment slightly acidic, around a pH of 3.8 to 4.5. BV develops when that balance tips, allowing other bacteria to overgrow and push the pH above 4.5. The exact trigger varies, but several things are known to shift this balance: new or multiple sexual partners, douching, and sometimes hormonal changes.
Douching is one of the strongest modifiable risk factors. Women who douche at least once a month have a 1.4 times higher risk of developing BV, and douching within the prior week more than doubles the risk. The practice strips away protective bacteria and disrupts the acidic environment they maintain. The vagina is self-cleaning, and water alone during bathing is sufficient for external hygiene.
Sexual activity plays a significant role too. Recent evidence has shifted thinking here considerably. The American College of Obstetricians and Gynecologists now recognizes that sexual transmission contributes to both new BV cases and recurrences, a position that was not well supported by older data.
Prescription Treatment Options
Antibiotics are the standard treatment. Your provider will typically prescribe one of the following:
- Metronidazole (oral or vaginal gel): The most commonly prescribed option. The oral version is usually taken twice daily for seven days. A vaginal gel version is also available, applied once daily for five days.
- Clindamycin (vaginal cream): Applied at bedtime for seven days. This is a good alternative if metronidazole causes stomach upset.
- Tinidazole (oral): Similar to metronidazole but sometimes better tolerated.
If you’re prescribed oral metronidazole, avoid alcohol completely during treatment and for two full days after finishing. The combination can cause intense nausea, vomiting, and flushing. This applies to tinidazole as well.
Most people notice the odor and discharge improving within two to three days of starting antibiotics, but finishing the full course is important even if symptoms clear early. Stopping short gives surviving bacteria a chance to rebound.
Why BV Keeps Coming Back
Recurrence is the most frustrating part of dealing with BV. The bacteria responsible, particularly Gardnerella vaginalis, form a protective layer called a biofilm on the vaginal walls. Research published in the American Journal of Obstetrics and Gynecology found that bacteria in this biofilm tolerate four to eight times higher concentrations of the natural acids that would normally keep them in check. Antibiotics can kill the free-floating bacteria and reduce symptoms, but the biofilm often survives and allows the infection to re-establish itself weeks or months later.
This is why a single round of antibiotics sometimes isn’t the end of the story. If BV returns three or more times in a year, your provider may recommend a longer or maintenance course of treatment to suppress the biofilm over time.
Treating Sexual Partners
For years, the standard advice was that partner treatment didn’t help. That has changed. In 2025, ACOG issued its first recommendation to consider treating male sexual partners of people with recurrent BV, using a combination of oral and topical antibiotics. The updated guidance follows newer studies showing that sexual activity plays a meaningful role in reintroducing the bacteria responsible for BV.
This recommendation currently applies to recurrent, symptomatic BV in people with male partners. Evidence is still limited for same-sex partnerships and nonmonogamous relationships, though the biological logic of shared bacteria applies broadly.
Probiotics and Vaginal Health
Probiotics containing specific lactobacillus strains can support recovery, though they aren’t a standalone treatment. The most studied strain for vaginal health is Lactobacillus rhamnosus GR-1, which has documented effects on reducing BV recurrence. The goal isn’t necessarily to colonize the vagina permanently but to help tip the microbial balance back toward protective bacteria during and after antibiotic treatment.
Look for probiotic products that list specific strains on the label rather than just “Lactobacillus blend.” Oral probiotics designed for vaginal health are the most practical option. Some providers also recommend vaginal probiotic suppositories, though the evidence for those is less consistent. Probiotics work best as a complement to antibiotics, not a replacement.
Prevention Strategies That Work
Preventing BV, or at least spacing out recurrences, comes down to protecting the vaginal microbiome:
- Skip douching entirely. This is the single most impactful change. Your vagina maintains its own pH, and douching disrupts the lactobacilli that keep harmful bacteria suppressed.
- Use condoms consistently. Semen is alkaline (pH around 7.2 to 8), which temporarily raises vaginal pH after unprotected sex. For people prone to recurrent BV, this pH shift can be enough to trigger a flare.
- Avoid scented products near the vulva. Scented soaps, bubble baths, sprays, and scented tampons or pads can irritate tissue and alter the vaginal environment. Unscented, gentle soap on external skin only is the safest approach.
- Wear breathable underwear. Cotton or moisture-wicking fabrics help keep the area dry, which discourages bacterial overgrowth.
BV During Pregnancy
Untreated BV during pregnancy increases the risk of preterm birth and low birth weight (under 5.5 pounds). If you’re pregnant and notice symptoms, getting tested promptly matters. BV is treatable during pregnancy with antibiotics that are safe for the developing baby. Some providers screen for BV in early pregnancy for people with a history of preterm delivery, even without symptoms.
Boric Acid Suppositories
Boric acid vaginal suppositories (typically 600 mg, inserted at bedtime) are sometimes recommended for recurrent BV that doesn’t respond well to standard antibiotics. Boric acid works by lowering vaginal pH and creating an environment that’s hostile to the biofilm-forming bacteria behind recurrences. It’s available over the counter but is best used under a provider’s guidance, particularly regarding how long to use it. Boric acid is toxic if swallowed and should never be taken orally or used during pregnancy.