Flagyl (metronidazole): What It Treats, How to Take It, and Safety Tips
Flagyl is the brand name for metronidazole. It's a cheap, effective antibiotic used for specific bacterial and parasitic infections. You probably know one rule already: no alcohol while on Flagyl. Beyond that simple warning, there are a few more things everyone should know before taking it.
What Flagyl treats and how it works
Flagyl kills anaerobic bacteria and some parasites by damaging their DNA. Doctors commonly prescribe it for bacterial vaginosis, trichomoniasis, giardiasis, and anaerobic infections in the gut or mouth. Dentists use it for certain tooth or jaw infections. It also appears in some H. pylori treatment combos and for surgical infection prevention in specific cases. If you have an infection caused by oxygen-loving bacteria, Flagyl won't help.
Dosing, side effects, and key warnings
Typical adult doses vary by infection: a common course for bacterial vaginosis is 500 mg twice daily for seven days, while trichomoniasis is often a single 2 g dose or 500 mg twice daily for seven days. Always follow the exact prescription from your clinician. Finish the full course even if you feel better.
Common side effects include nausea, stomach pain, metallic taste, headache, and dizziness. If you take Flagyl for more than two weeks or in high doses, there's a small risk of peripheral neuropathy — numbness or tingling in hands or feet. Stop the drug and call your doctor if you get new weakness, trouble walking, severe rash, or persistent numbness.
Do not drink alcohol or use products with propylene glycol while on Flagyl and for at least 48 hours after finishing. Mixing alcohol can cause flushing, nausea, vomiting, and rapid heartbeat. Tell your doctor if you have liver disease, a blood disorder, or take warfarin — metronidazole can raise warfarin levels and increase bleeding risk. Pregnant people should avoid Flagyl in the first trimester unless the doctor says it's needed. Breastfeeding is sometimes allowed but check with your provider.
Serious allergic reactions are rare but possible. If you have a history of severe allergic reactions to nitroimidazole drugs, do not take Flagyl.
Buying Flagyl online? Only use licensed pharmacies that ask for a valid prescription. Watch for sites selling antibiotics without a prescription or offering suspiciously low prices — they might ship fake or substandard pills. Check reviews, verify pharmacy credentials, and prefer pharmacies with clear contact info and secure payment. If an online source sounds too good to be true, trust your gut.
Questions for your doctor: Is Flagyl the right choice for my infection? Which dose and how long? What side effects should I expect? Should I avoid other drugs or supplements while taking it? Ask these before starting treatment.
Store Flagyl at room temperature away from moisture. If you miss a dose, take it when you remember unless it's time for the next dose—don't double up. Seek care for severe allergic reaction, persistent bloody diarrhea, high fever, or yellowing skin. Share your med list with the pharmacist.
