Metronidazole 400mg Tablets
  • Metronidazole 400mg Tablets

Metronidazole 400mg Tablets

Medication features

  • Oral Antibiotic which eliminates bacteria
  • One or Seven-day course treatments available
  • For female patients only


Order Metronidazole 400mg Tablets Online

You can request to buy Metronidazole online from our UK registered online doctor and pharmacy service. Metronidazole is a prescription medicine and you must complete a short online medical questionnaire as part of your order. This is assessed by our doctors, who will prescribe the medicine if suitable to do so. If approved, a prescription is passed to our online pharmacy team to dispense. Please note, your medicine will be dispatched to your address via Royal Mail.

What is Metronidazole?

Metronidazole is an antibiotic used to treat a variety of infections, including bacterial vaginosis in women. Bacterial vaginosis occurs when there is an imbalance in the natural bacteria in the vagina, causing bacteria to overgrow. Metronidazole controls the overgrowth by killing off some of the overgrown bacteria, restoring balance. As well as tablets, Metronidazole is available as a vaginal gel to treat bacterial vaginosis.

This is prescribed as a treatment for women with bacterial vaginosis (BV). It can be prescribed as a 7-day course of tablets or as a high strength single dose course. 

How does Metronidazole work?

Bacterial vaginosis (BV) is caused by a change in the natural balance of bacteria in the vagina. This causes an overgrowth of certain bacteria, such as Gardnerella vaginalis. Metronidazole works by targeting the DNA of the overgrown bacteria, breaking its structure which causes it to die. This can successfully rebalance the natural bacteria of the vagina, treating bacterial vaginosis.

Metronidazole and Bacterial Vaginosis

Bacterial vaginosis (BV) symptoms are a grey or white discharge that tends to be thin, watery and have a fish-like odour. BV is not a sexually transmitted infection and is not something that is passed to sexual partners. As bacterial vaginosis has similar symptoms to other vaginal conditions, it is important that it is not confused with thrush, an STI or cystitis as these will require different types of treatments.

Metronidazole is effective for BV because it targets the specific bacteria causing the infection. Metronidazole will not be effective for conditions such as thrush or cystitis because they are caused by fungus or bacteria against which metronidazole is not effective.

Metronidazole Dose

Metronidazole for BV is usually treated using Metronidazole 400mg tablets, but there are two different dosage types. The first Metronidazole for BV dosage is to take one tablet twice a day for 5 to 7 days. 

The other dosage that can be prescribed is to take Metronidazole 400mg as 5 tablets at once, as a single dose. Both dosages are effective at treating BV, but some women may prefer the single-dose option because it is easier than taking a 7-day course of tablets. Both treatments will take around 5-7 days to fully clear BV.

When starting a course of treatment with antibiotics, it is important that you finish your course completely. Doing so ensures all the bacteria causing the infection is cleared and does not return. Only stop treatment if allergies or serious side effects occur.

You should take oral Metronidazole exactly as your doctor has prescribed.

Metronidazole and Alcohol

Do not drink alcohol during or within 48 hours of a metronidazole course. Metronidazole stops the body from being able to break down alcohol fully, leaving a breakdown product in the body which can cause severe nausea, vomiting, hot flushes, stomach pain and headaches. It is a similar experience to having a severe hangover.

Metronidazole Summary


Take ONE tablet TWICE daily for 7 days (7-day course) or take 5 tablets as a single dose (single day course).

Type of medicine

Antibiotic tablets - nitroimidazole


Kills bacteria by breaking down bacterial DNA

Active Ingredient

Metronidazole 400mg


From £14.95

Side Effects

Can include nausea, diarrhoea, vomiting, loss of appetite

Metronidazole Tablet Prices

1-day course (5 tablets)


7-day course (14 tablets)


Alternative Treatments

Bacterial vaginosis can also be treated with topical treatments like Zidoval Gel and Dalacin Cream. Zidoval contains Metronidazole as the active ingredient and is applied at bedtime for 5 days. Dalacin contains the active ingredient clindamycin, which is also an antibiotic. The cream is usually applied at bedtime for 7 days.


What is Metronidazole used for?

Metronidazole can be used to treat several types of infections such as dental infections, pelvic inflammatory disease, and bacterial vaginosis (BV). It mostly targets bacteria called anaerobic bacteria and is not suitable to treat all types of infections.

How can I buy Metronidazole online?

To buy metronidazole online you will need to complete an online assessment reviewed by a UK registered doctor. A registered online pharmacy can then send metronidazole to you through the Royal Mail service. Simple Online Pharmacy provides both of these services in one place for maximum safety and convenience.

What are the side effects of Metronidazole?

It can cause side effects such as diarrhoea, nausea, vomiting, and an unpleasant taste in the mouth. 

Other side effects can be more serious such as causing liver problems, dark urine, blood problems or pancreatitis. Although these are rare, you should stop taking the tablets and immediately contact your doctor if you experience any of the above.

Can you drink alcohol on Metronidazole?

Drinking alcohol and taking Metronidazole can cause side effects like headaches, flushing, and nausea. You should not drink alcohol while taking the tablets and for 48 hours after stopping the course of tablets.

Can you buy Metronidazole over the counter?

Metronidazole, in the UK, is a prescription-only medicine that cannot be bought over the counter. However, if you have BV you can request Metronidazole to buy online from our UK registered online doctor service. You must complete an online medical consultation for our doctors to assess.

If your request is approved by our doctors, a prescription will be sent to our online pharmacy team. From here, it will be dispensed and dispatched to your chosen delivery address. If you have any queries, please contact our customer service team.

Side Effects

Metronidazole Side Effects

Like any medicine, metronidazole can cause adverse effects although not everyone will experience them. It can cause side effects such as diarrhoea, nausea, vomiting, and an unpleasant taste in the mouth.  

Other side effects can be more serious such as causing liver problems, blood problems or pancreatitis. Although these are rare, you should stop taking the tablets and immediately contact your doctor if you experience any of the above.

See the patient information leaflet for further information, or ask your doctor or pharmacist for medical advice.


Info Leaflet

Before taking any medication, it is important to read the Patient Information Leaflet. You can find information leaflets for your medicines by typing them into the search bar at, or by contacting us.


Other conditions and Metronidazole

You should not take this medicine if you are allergic to Metronidazole or any of the ingredients in the tablets. This medicine may not be suitable for people with liver or kidney problems, nervous system diseases, or people having dialysis. If any of the above applies to you, ask your doctor or pharmacist for advice.  

Interactions with other medicines

Certain medicines can interact with Metronidazole in the body and should not be taken together. This includes lithium, disulfiram, some anti-epilepsy medicines, and blood-thinning medicines like warfarin. 

See the patient information leaflet for a complete list of drug interactions. If you are unsure about Metronidazole and your other medication, ask your doctor or pharmacist for medical advice.

Metronidazole in pregnancy and breastfeeding

The effects of metronidazole in pregnancy are not well established. Due to this, it is recommended to avoid metronidazole in pregnancy unless absolutely necessary. Always consult your doctor about your options before using any medicines while pregnant.

Metronidazole can pass into the breastmilk which can result in side effects in the baby. If possible avoid use during breastfeeding if possible. Always consult your doctor before using medicines during breastfeeding.

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Dalacin Cream

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Metronidazole 400mg Tablets

Medication Simple Online Pharmacy
400mg x 1 Day Course 5 x 400mg Tablets £14.95
7 Day Course 14 x 400mg Tablets £17.50
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