Bacterial vaginosis (BV) is treated with prescription antibiotics, either taken by mouth or applied inside the vagina. Most people notice symptoms improving within two to three days of starting treatment, and a full course typically lasts five to seven days. The two main antibiotics used are metronidazole and clindamycin, and your provider will help choose the best option based on your preferences and medical history.
First-Line Antibiotic Options
BV treatment centers on two antibiotics that work against the anaerobic bacteria responsible for the infection. Both are available in oral and vaginal forms, so the choice often comes down to convenience, side effects, and how you feel about each method of delivery.
Metronidazole is the most commonly prescribed option. It comes as an oral tablet taken twice a day for seven days, or as a vaginal gel applied at bedtime for five days. The oral form is straightforward but can cause nausea, a metallic taste, and stomach upset. You need to avoid alcohol during treatment and for at least 24 hours after finishing, because the combination can trigger severe nausea and vomiting. The vaginal gel avoids most of those whole-body side effects but requires nightly application.
Clindamycin is the main alternative. It’s available in three forms: a vaginal cream applied at bedtime for seven days, a vaginal ovule (a small suppository) inserted at bedtime for three days, or an oral capsule taken twice daily for seven days. The three-day ovule course is the shortest treatment option available, which some people prefer. One important note: clindamycin cream and ovules are oil-based, which can weaken latex condoms and diaphragms during treatment and for several days afterward.
What to Expect During Treatment
Symptoms like unusual discharge and fishy odor typically start fading within the first two to three days of treatment. Even so, it’s important to finish the entire course of antibiotics. Stopping early increases the chance that the bacteria aren’t fully cleared, which can lead to a quick return of symptoms.
Vaginal treatments can cause mild local irritation or increased discharge during the course. Oral antibiotics are more likely to cause digestive side effects like nausea, diarrhea, or bloating. These side effects are generally mild and resolve once you finish the medication. If you experience a yeast infection after treatment (a common occurrence, since antibiotics can disrupt the vaginal environment further), over-the-counter antifungal treatments are usually sufficient.
Why BV Comes Back So Often
Recurrence is the single biggest frustration with BV treatment. Between 50% and 80% of women experience a recurrence within 6 to 12 months of finishing antibiotics. That’s not a failure of the medication itself. It reflects a deeper problem with how BV works.
The bacteria that cause BV, particularly Gardnerella vaginalis, form a sticky protective layer called a biofilm on the vaginal wall. This biofilm acts like a shield: antibiotics can kill the free-floating bacteria and relieve symptoms, but they often fail to fully penetrate and destroy the biofilm underneath. Once the antibiotic course ends, the surviving bacteria embedded in that biofilm can repopulate and trigger another episode. The biofilm also harbors multiple bacterial species, making it especially resistant to a single antibiotic.
Other factors that contribute to recurrence include having a new sexual partner or multiple partners, douching, and not using condoms. Hormonal shifts around menstruation can also create conditions that favor the bacteria responsible for BV.
Managing Recurrent BV
If BV keeps returning, your provider may recommend a longer-term suppressive approach. This typically means completing a standard treatment course first, then continuing with a lower-frequency maintenance regimen. For example, some providers prescribe vaginal metronidazole gel used once or twice a week for several months to keep symptoms from returning. The goal is to suppress bacterial regrowth long enough for the vaginal environment to stabilize.
Boric acid vaginal suppositories are sometimes used as an add-on therapy, particularly for recurrent cases. They work by lowering vaginal pH, which creates an environment less hospitable to the bacteria that cause BV. Boric acid is not a replacement for antibiotics, and it should only be used vaginally (it is toxic if swallowed). Evidence supporting its effectiveness is still limited, but some providers recommend it as part of a combination strategy for stubborn recurrences.
Does Your Partner Need Treatment?
BV has not traditionally been classified as a sexually transmitted infection, and routine treatment of male sexual partners has not been standard practice. However, research increasingly suggests that the bacteria involved in BV can be shared between sexual partners, and that reinfection from a partner may contribute to recurrence. Some recent clinical trials have explored whether treating male partners with antibiotics reduces recurrence in women, with promising early results.
Current guidelines do not yet recommend routine partner treatment, but this is an area where the medical consensus is actively shifting. If you’re dealing with frequent recurrences and have a regular male sexual partner, it’s worth discussing partner treatment as an option with your provider. For women who have sex with women, BV-associated bacteria can be shared between partners, so both partners being evaluated makes sense if recurrences are a problem.
Treatment During Pregnancy
BV during pregnancy is treated with the same antibiotics, though providers generally prefer oral metronidazole or oral clindamycin over vaginal formulations. Treating BV in pregnancy matters because untreated infections are associated with preterm birth and low birth weight. Both metronidazole and clindamycin are considered safe during pregnancy, including in the first trimester. If you’re pregnant and notice a change in vaginal discharge or odor, getting tested promptly allows for early treatment.
Reducing Your Risk of Recurrence
While no strategy guarantees BV won’t return, a few habits help tip the odds in your favor. Avoiding douching is one of the most important steps, since douching disrupts the natural balance of vaginal bacteria. Using condoms consistently, especially with new partners, reduces exposure to bacteria that can shift the vaginal environment. Choosing fragrance-free soaps and avoiding scented products in the genital area also helps maintain a healthy bacterial balance.
Some people take oral or vaginal probiotics containing Lactobacillus strains to try to restore protective bacteria after antibiotic treatment. The evidence for probiotics in preventing BV recurrence is mixed. Some small studies show modest benefit, while larger reviews have found inconsistent results. Probiotics are unlikely to cause harm, but they shouldn’t be relied on as a standalone prevention method.