Bacterial vaginosis (BV) is treated with prescription antibiotics, either taken by mouth or applied inside the vagina as a gel or cream. The most commonly prescribed option is metronidazole, a seven-day course of oral pills taken twice daily. Several alternatives exist depending on your preferences, side effects, and whether BV keeps coming back.
First-Line Antibiotic Options
The CDC recommends three primary treatments for BV, all considered equally effective as first choices:
- Metronidazole oral pills: Taken twice a day for seven days. This is the most widely prescribed option.
- Metronidazole vaginal gel: Applied once daily for five days using a prefilled applicator. This route works well if you want to avoid the side effects that sometimes come with oral antibiotics, like nausea or a metallic taste.
- Clindamycin vaginal cream: Applied at bedtime for seven days. This is the preferred choice if you have an allergy or intolerance to metronidazole.
All three clear BV at similar rates. The main difference is how you take them and the side effect profile. Oral metronidazole affects your whole body, so digestive side effects like nausea and stomach upset are more common. The vaginal options keep the medication more localized, which generally means fewer systemic side effects but requires the routine of nightly applicator use.
Alternative Treatments
When the first-line options don’t work well for you, several alternatives are available. Clindamycin can also be taken as an oral pill twice daily for seven days, or as a vaginal suppository (ovule) used at bedtime for three days. Tinidazole, a close relative of metronidazole, offers a shorter course: either a two-day or five-day regimen depending on the dose.
Secnidazole is a newer option that works as a single oral dose, which is appealing if sticking to a multi-day regimen is difficult. A meta-analysis found that a single 2-gram dose of secnidazole performs about as well as a full course of metronidazole, with no significant difference in cure rates or side effects between the two. The convenience factor is the main advantage.
Alcohol and Metronidazole
You’ve likely heard that mixing alcohol with metronidazole causes a severe reaction: flushing, nausea, vomiting, rapid heartbeat. This warning is standard on every prescription label, and most providers will tell you to avoid alcohol during treatment and for at least 24 to 48 hours after finishing the course. The actual clinical evidence behind this interaction is weaker than you might expect. A review in Antimicrobial Agents and Chemotherapy noted that the reaction “occurs with uncertain frequency and with varied severity,” and that the data are conflicting. Still, it’s a simple enough precaution to follow for a week.
Do Probiotics Help?
Because BV is fundamentally a disruption in vaginal bacteria, with protective Lactobacillus species declining and other organisms overgrowning, probiotics are a logical idea. The clinical picture is mixed but leaning positive. In one trial, women who used vaginal Lactobacillus acidophilus capsules for six days saw a 57% improvement rate compared to 0% in the placebo group. Oral probiotics containing L. rhamnosus and L. fermentum strains, taken for about two months, have also shown reductions in BV recurrence and restoration of healthier vaginal bacteria in some studies.
That said, other trials found no meaningful difference between probiotics and placebo. The inconsistency likely comes down to which strains were used, how they were delivered, and how long treatment lasted. Probiotics are not a reliable standalone treatment for active BV, but they may have a supporting role alongside antibiotics, particularly for people dealing with repeated episodes.
When BV Keeps Coming Back
Recurrence is the most frustrating part of BV. Up to 66% of women experience a return of symptoms within a year of their initial treatment. The standard approach for recurrent BV typically involves a longer or repeated course of the same antibiotics, sometimes followed by a maintenance phase where vaginal metronidazole gel is used periodically to keep symptoms at bay.
Boric acid vaginal suppositories are another option that some providers recommend for recurrent cases, though they’re not part of the standard CDC-recommended regimens. They’re available over the counter and work by lowering vaginal pH, creating an environment that’s less hospitable to the bacteria that cause BV. Boric acid should never be taken orally, as it’s toxic when swallowed.
Treating Sexual Partners
For years, the standard advice was that treating male sexual partners didn’t help prevent BV from coming back. That changed in 2025, when ACOG updated its guidelines for the first time to recommend considering concurrent partner treatment for recurrent BV. Newer evidence shows that sexual activity plays a significant role in both initial BV and recurrence, and treating male partners with a combination of oral and topical antibiotics can help break the cycle.
This recommendation applies specifically to recurrent, symptomatic BV in women with male sexual partners. Evidence for same-sex partners and people in nonmonogamous relationships is still limited.
BV Treatment During Pregnancy
BV during pregnancy is treated with the same antibiotics used in non-pregnant patients. Metronidazole, both oral and vaginal, and clindamycin are all considered safe to use. Symptomatic BV in pregnancy is typically treated because the infection has been associated with an increased risk of preterm delivery and other complications. Your provider will choose the specific regimen based on your trimester and medical history.
What to Expect During Treatment
Most people notice improvement within two to three days of starting antibiotics, though it’s important to finish the full course even if symptoms clear up early. Stopping early increases the chance of the infection returning. Common side effects of oral metronidazole include nausea, a metallic taste in the mouth, and occasional headaches. Vaginal treatments can sometimes cause mild irritation or a yeast infection, since antibiotics can disrupt the balance of vaginal flora even further.
If you’re using clindamycin cream or ovules, keep in mind that oil-based vaginal products can weaken latex condoms and diaphragms for up to five days after use. You’ll want to use an alternative form of contraception during that window if needed.