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Metronidazole

Brand names: Flagyl, MetroGel

Metronidazole is an antibiotic for bacterial vaginosis, trichomoniasis, C. diff, and some gut and dental infections.

Brand namesFlagyl, MetroGel
Type of medicineAntibiotic
Prescription?Prescription
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

It also comes as a gel for rosacea and for bacterial vaginosis.

What it's used for

  • Bacterial vaginosis
  • Trichomoniasis
  • C. diff infection
  • Giardia and other gut infections
  • Some dental and pelvic infections
  • Rosacea (gel)

How to take it

  • Take it with food to lower stomach upset.
  • Finish the full course.
  • Sex partners of people with trichomoniasis need treatment too.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Metallic taste
  • Nausea
  • Headache
  • Dark urine (harmless)
Call 911Seizure
Call your provider todayNumbness, tingling, or burning in hands or feet
Call your provider todayConfusion, unsteady walking, or slurred speech
Call 911A blistering, peeling, or widespread red rash, especially with fever

Warnings

  • Long-term use can damage nerves.

Other medicines, foods, and alcohol

  • Don't drink alcohol during treatment and for 3 days after; it can cause severe vomiting, flushing, and fast heartbeat.
  • It strongly raises the effect of warfarin.
  • It can raise lithium levels.
  • Don't take within 2 weeks of disulfiram.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Can be used in pregnancy for some infections. Talk with your provider.

Missed doses, overdose, and storage

If you miss a dose

Take it as soon as you remember. If it's almost time for the next dose, skip the missed one. Don't double up, and still finish the full course.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

Sources

Last updated 2026-11-13.