Metronidazole vaginal gel is one of three first-line treatments for bacterial vaginosis, and using it correctly is straightforward: you fill the provided applicator, insert it vaginally, and repeat once daily for five days. The standard prescription is a 0.75% concentration gel, and most providers recommend applying it at bedtime so the medication stays in place overnight. Here’s everything you need to know to use it properly and get the best results.
The Standard Dosing Schedule
Each dose is one full applicator of gel, which works out to about 5 grams of product. Your provider will prescribe it as either once or twice daily for five days. The once-daily schedule is more common and is what the CDC recommends in its treatment guidelines: one applicator at bedtime for five consecutive nights.
If you’re prescribed twice-daily dosing, you’ll apply one applicator in the morning and one in the evening. Either way, the full course is five days. Finish all five days even if your symptoms clear up sooner, because stopping early increases the chance the infection comes back.
How to Apply the Gel Step by Step
Before you start, wash your hands with soap and water. Each tube of gel comes with pre-filled or fillable applicators depending on the brand. If the applicator needs to be filled, attach it to the tube and squeeze gently until the plunger is pushed back to the fill line.
Lie on your back with your knees bent, or stand with one foot elevated on a chair or the edge of the bathtub. Gently insert the applicator into the vagina as far as it comfortably goes, similar to inserting a tampon. Push the plunger slowly to release the full dose of gel, then withdraw the applicator.
If your applicator is reusable (designed for the full five-day course), pull it apart into its two pieces after each use and wash both with warm water and soap. Let them air dry completely before reassembling. Dispose of the applicator after you finish the full course of treatment. If your prescription comes with single-use applicators, simply throw each one away after use.
Why Bedtime Application Works Best
Applying the gel right before you go to sleep gives the medication hours of uninterrupted contact with the vaginal walls. When you’re lying down, gravity keeps the gel in place rather than letting it leak out. If you’re on a twice-daily schedule, you may notice some discharge after the morning dose, which is normal. A thin panty liner can help with any leakage during the day.
What to Avoid During Treatment
Sexual intercourse during the five-day course can reduce the effectiveness of the medication. Avoid vaginal sex until you’ve completed all five days of treatment.
Alcohol is also off-limits. Metronidazole, even in gel form, can cause an unpleasant reaction when combined with alcohol, including nausea, vomiting, flushing, and a rapid heartbeat. Avoid alcoholic beverages and any products containing alcohol or propylene glycol during treatment and for at least 24 hours after your last dose.
One reassuring detail: unlike some vaginal creams (such as clindamycin cream, the other topical option for BV), the gel formulation of metronidazole does not contain oils that degrade latex. So if you do use condoms after completing treatment, the gel itself won’t have compromised them.
If You Miss a Dose
Apply the missed dose as soon as you remember. If it’s already close to the time for your next scheduled dose, skip the missed one and continue with your regular schedule. Never double up by using two applicators at once to make up for a forgotten dose.
Side Effects to Expect
The most common side effects are mild and local: a metallic taste in your mouth (yes, even from a vaginal gel, because small amounts are absorbed into the bloodstream), mild cramping, and increased vaginal discharge. These typically don’t require any action and resolve once you finish the course.
One side effect worth watching for is a vaginal yeast infection. Metronidazole kills the bacteria causing BV, but it can also disrupt the balance of organisms in the vagina enough to let yeast overgrow. If you develop new itching, thick white discharge, or irritation after starting or finishing the gel, that’s likely a yeast infection rather than a sign the BV treatment isn’t working. Over-the-counter antifungal treatments can address it, but it’s worth mentioning to your provider.
Using the Gel While Breastfeeding
The vaginal gel is generally considered compatible with breastfeeding. Because so little metronidazole is absorbed into the bloodstream from the gel (far less than from oral tablets), the amount that reaches breast milk is negligible. This is actually one reason providers sometimes prefer the gel over oral metronidazole for nursing parents. Just wash your hands thoroughly after application so your baby doesn’t come into contact with any residual gel.
How to Tell if the Treatment Worked
BV symptoms, particularly the fishy odor and thin grayish discharge, typically improve within the first few days of treatment. By the time you finish the five-day course, most people notice a significant difference. If your symptoms haven’t improved at all, or if they return within a few weeks, contact your provider. Recurrent BV is common, affecting roughly half of treated individuals within 12 months, and may require a different approach such as extended or suppressive therapy.
You don’t necessarily need a follow-up visit if your symptoms resolve completely. But if you’re pregnant or if BV keeps coming back, your provider may want to confirm that the infection has cleared with a repeat exam.