Some infections thrive precisely where there is no oxygen — deep in tissue, in abscesses, in the gut.
Metronidazole is activated by those oxygen-free conditions, which is what makes it so selective for them.
Without prescription, plain packaging. No alcohol, during or for days afterwards.
The mechanism is genuinely clever and it explains the whole drug.
Metronidazole arrives inactive. It does nothing at all in ordinary oxygenated tissue.
Inside an organism that lives without oxygen, the chemistry is different. The molecule gets chemically reduced, and that converts it into a highly reactive form.
That reactive form shreds the organism's DNA. Irreparably, and fast.
Your own cells sit in oxygen, so the activation never happens there. The selectivity is built into the chemistry rather than into targeting.
What it treats
Bacterial vaginosis
Trichomonas infection
Dental and gum infections
Abscesses
Abdominal and pelvic infections involving anaerobes
Amoebic infections and giardia
Part of combination treatment for stomach ulcer bacteria
Some serious gut infections after other antibiotics
With trichomonas, the partner needs treating at the same time. Otherwise it just goes back and forth indefinitely, and that is the most common explanation for an infection that will not clear.
Alcohol: the rule with no exceptions
If you remember one thing from this page, make it this.
Metronidazole blocks an enzyme in the chain that breaks down alcohol. The intermediate product builds up instead of being cleared, and that compound is responsible for most of what a hangover feels like.
The result arrives fast and hard: flushing, violent nausea and vomiting, pounding headache, racing heart, a drop in blood pressure.
And it catches people out in places they never thought about.
Mouthwash containing alcohol
Cough syrups and tinctures
Sauces, desserts and dishes cooked with wine
Some herbal drops
Low-alcohol beers, which are not alcohol-free
And it does not end with the last tablet. Keep clear for several days afterwards — the enzyme needs time to recover.
What is the metallic taste about?
Very common, and harmless, but nobody warns people and it is unpleasant.
A persistent metal taste in the mouth that makes food taste wrong. It goes away a few days after the course finishes.
Sugar-free mints, a strong-flavoured mouthwash without alcohol, or just eating things with a sharper taste all help a bit. Nothing gets rid of it entirely while you are taking it.
Darker urine is not a problem
Urine can go reddish-brown. It looks alarming the first time.
It is a harmless breakdown product of the drug and has nothing to do with blood or with kidney trouble. It stops when the course does.
Finish the course, even when you feel fine
This is the single most important line on the page.
After two or three days the fever usually breaks and you feel more or less human again. The temptation to stop is obvious.
But feeling better only means the bacterial numbers have dropped far enough for your immune system to cope. Some are still alive — and they are the toughest ones, the ones that held out longest.
Stop there and you leave exactly those behind. The infection comes back, harder to treat than the first time. That is how resistance builds, one shortened course at a time.
Take the full course. Even if you have felt well for a week.
Possible side effects
Metallic taste
Nausea, loss of appetite
Headache
Darker urine
Dry mouth
Dizziness
Thrush
Less commonly, longer courses can cause tingling or numbness in the hands and feet. Report that rather than continuing — it needs the treatment reviewing.
Get help for seizures, confusion, difficulty with coordination or problems with vision.
Things that interact
Alcohol, in any form
Warfarin — bleeding risk rises
Lithium
Phenytoin and phenobarbital
Disulfiram, which must not be combined
If you take blood thinners, this combination needs monitoring rather than assuming it will be fine.
Ordering without prescription: how it works
Since alcohol has to stay out of the picture for the whole course and after, it is worth starting with the full amount in hand.
Pick the strength and the pack size, put in a delivery address, confirm. Couple of minutes, any time of day, no queue and no conversation accross a counter.
It goes out in plain packaging. No pharmacy name on the outside, nothing that hints at what is inside. How long delivery takes depends on where the parcel is headed.
On price it comes down to strength and pack size. Larger packs generally work out better per unit.
If something arrives damaged anywhere in the UK, send the order number and a photograph the same day. We replace free of charge or refund in pounds. Do not use medication from a damaged blister.
