Medication

Fluconazole

An oral antifungal used mostly for yeast infections of the skin and mucous membranes. It is often a single dose or a weekly tablet, and it interacts with a long list of other medicines.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Fluconazole. Never cropped: the tone strip and the corner logo depend on the full frame.

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Fluconazole is the tablet I use when the problem is yeast rather than ringworm — thrush, yeast in a skin fold, yeast folliculitis on the back and chest. For nails and scalp I use terbinafine instead, because fluconazole is weaker against those fungi. What I check every time is the rest of your medicine list, because fluconazole slows how the liver clears warfarin, some statins, some diabetes tablets and several heart medicines. Yeast in a fold also comes back if the fold stays damp — the tablet clears the yeast, but keeping the area dry is what keeps it away.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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Also calledDiflucan
Drug classTriazole antifungal
Taken asTablet or liquid suspension
Typical courseOne dose for some infections, weekly for skin, longer for nails
Time to workA few days for thrush, 2 to 4 weeks for skin
Prescription onlyYes

What It Is

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Fluconazole is an antifungal taken by mouth. In skin it is used mainly for yeast: thrush in the mouth, vaginal yeast infection, yeast in warm folds such as under the breasts or in the groin, and yeast folliculitis on the back and chest. It also treats some ringworm-type infections when a cream has not worked, and is used off-label for nail fungus as a weekly tablet. It absorbs and holds unusually well for an antifungal. Almost all of a dose gets in whether or not you have eaten, it lasts about a day and a half, and it collects in skin and sweat — which is why some infections need one tablet and others one tablet a week.

How It Works

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Fungi build their cell walls from a fatty molecule called ergosterol. Fluconazole blocks the fungal enzyme needed to make it, sometimes written as 14-alpha-demethylase. Without ergosterol the wall leaks and the fungus cannot grow.

For most yeasts this stops growth rather than killing outright, so your immune system finishes the job. That is why the length of the course matters more than the size of the dose, and why a suppressed immune system needs longer treatment.

Humans have related liver enzymes that handle medicines, and fluconazole partly blocks two of them. That is why this drug has such a long interaction list.

Here is where Fluconazole acts in the skin, and what the others do instead.

About Fluconazole
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Skin basics
BARRIEREPIDERMISDERMISPOREOILGLANDKILLS YEASTARRIVES BY BLOODSTOPS PLUGS FORMINGUNCLOGS THE POREKILLS BACTERIALOWERS OIL PRODUCTIONKILLS MITES

The yeast involved here lives on everyone's skin and only causes trouble when it overgrows in oil. Fluconazole reduces it, which is why the flaking and itching settle and why it comes back if treatment stops for good. A pill, for what a cream cannot reach.

Fluconazole arrives from the inside, carried to the skin by the blood, rather than crossing the barrier from outside. That is why it works everywhere at once, and why it needs monitoring.

Retinoids change how the lining of the pore sheds its cells, so the plug that starts a spot stops forming in the first place. That is why they prevent spots rather than treat the ones already there, and why the first weeks can look worse before they look better.

Salicylic acid dissolves in oil, so it gets down inside the pore rather than sitting on the surface, and loosens the plug of dead skin and sebum blocking the way out.

This works on the bacteria growing in an inflamed pore. Less bacteria means less for the immune system to react to, which is what takes the redness and soreness out of a spot.

This works upstream of the spot, on the gland itself. Less oil means fewer plugs, less for bacteria to feed on and less inflammation, which is why it changes the pattern rather than clearing one spot.

Everyone carries these mites in their follicles. In some people the immune system reacts to them, and reducing their number reduces the bumps and the redness that come with them.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

What It Treats

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Close-up of light skin with a scattered cluster of small pink raised bumps, some with tiny white tips
Fungal Acne (Malassezia Folliculitis)
Strong evidence
The other antifungal tablet used here, often as a weekly dose for a few weeks. It suits people who cannot take itraconazole. Tablets clear the yeast but do not change the heat, sweat and occlusion that brought it on, so a maintenance wash is usually continued afterwards.
Tinea Versicolor
Tinea Versicolor
Strong evidence
The other short-course tablet, sometimes given as a single dose repeated a week later. It works about as well as itraconazole for a widespread rash. Neither tablet stops it coming back, so the monthly wash is still the plan afterwards. If you are pregnant or breastfeeding, ask the doctor managing your pregnancy before taking either.
Nail Fungus (Onychomycosis)
Nail Fungus (Onychomycosis)
Moderate evidence
Taken once a week rather than daily, which suits people who struggle with a long daily course. Cure rates sit below terbinafine and it usually has to be continued until the nail has grown out, which can be a year. It also interacts with a number of other medicines.
Folliculitis
Moderate evidence
An antifungal tablet, usually a short weekly course, for yeast folliculitis that is widespread or has not cleared with washes alone. It works faster and more completely than topical treatment on the chest and back. The yeast lives on everyone and comes back, so it is normally followed by an antifungal wash once a week to hold it.
Jock Itch
Moderate evidence
A once-weekly tablet for two to four weeks, sometimes chosen because the schedule is easy to keep to. It works for jock itch but is generally a little less effective against these fungi than terbinafine or itraconazole. It is the more useful option when yeast is also in the picture. Ask your doctor if you are pregnant or breastfeeding.
Athlete's Foot
Athlete's Foot
Moderate evidence
A once-weekly tablet, used for skin infection that has not cleared with cream when the other two do not suit. It is less effective than terbinafine for the dermatophytes that cause athlete's foot, and slower for nails. If you are pregnant or breastfeeding, ask the doctor managing your pregnancy before taking any antifungal tablet.
Ringworm
Moderate evidence
A once-weekly tablet, used mainly when terbinafine and itraconazole do not suit. It clears dermatophyte infections less reliably than either, so it is a second-line option here rather than a first choice, even though it is the antifungal most people have heard of.

Not the Best For

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Dandruff
Dandruff
Limited evidence
An antifungal tablet, occasionally used for a short course when seborrheic dermatitis is severe, widespread, or not responding to anything applied to the skin. Ordinary dandruff never needs it. It also does not keep it away — shampoo maintenance still has to carry on afterwards — and it interacts with a number of common medicines.
Seborrheic Dermatitis
Seborrheic Dermatitis
Limited evidence
A weekly antifungal tablet sometimes used for widespread or stubborn disease when itraconazole does not suit. The evidence for it in this condition is thinner. Either way, tablets clear a flare rather than change the condition, so the shampoo or cream still has to continue afterwards.
Nail fungus
Doesn't work
Its weakest use. Cure rates are lower than with terbinafine and the course is much longer, so it is mostly kept for people who cannot take terbinafine.
Ringworm, jock itch and athlete's foot
Doesn't work
It works against this family of fungi, but terbinafine is more effective and is usually chosen first.
Resistant yeast
Doesn't work
Not all Candida responds, and some species are naturally resistant. That is one reason a swab is sent when an infection keeps coming back.

Forms

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Tablets are the usual form, taken with or without food. Antacids, stomach acid and meals do not meaningfully change absorption.

A liquid suspension is made for children and anyone who cannot swallow tablets.

An intravenous form exists for serious hospital infections, not for skin conditions.

Strengths

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Tablets come in a few fixed strengths.

WeakestStrongest
50 mg100 mg150 mg200 mg
The low strength
50 mg
Daily dosing in thrush and in children.
The step up
100 mg
Daily thrush courses of one to two weeks.
The single-dose strength
150 mg
The one-tablet treatment for vaginal yeast, and the usual weekly tablet for skin.
The higher strength
200 mg
For stubborn or widespread infections.

Dose

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Dosing here is unusual
for several skin conditions it is a single tablet, or one tablet a week, rather than daily.
Starting dose
Depends what is being treated. Vaginal yeast is often one 150 mg tablet. Oral thrush is usually 200 mg on day one, then 100 mg daily. Skin and fold infections are commonly 150 mg once a week.
Going up
Not a ladder. If one dose has not settled vaginal yeast, a second about three days later is common. Persistent or widespread infections get a higher weekly dose or a longer course, not a bigger daily one.
Usual dose
150 mg weekly for yeast or ringworm on the skin, typically 2 to 4 weeks. Thrush is treated for 7 to 14 days. Yeast folliculitis on the back and chest needs a few weeks of weekly dosing plus an antifungal wash.
Total course
One dose for simple vaginal yeast, one to two weeks for thrush, two to four weeks for skin, six months or more for nails, where it is off-label in the United States. Kidney problems lower the dose.

How to Take It

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When to take it: With or without food, any time of day. Fluconazole absorbs almost completely either way, and antacids do not block it. On a weekly tablet, pick a fixed day and set a reminder. Weekly medicines are the easiest to lose track of. Mild nausea or a headache in the first day or two is common; a meal usually helps.

If you miss a dose: On a daily course, take it when you remember unless the next dose is close, and never double up. On a weekly course, take the missed tablet as soon as you notice and carry on with your usual day. A single dose that made you sick straight away may not have been absorbed, so ask rather than repeating it.

What to Expect

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Hours 1 to 24 | Taking it
One tablet, with or without food. Nausea or headache, if they come, come now.
Days 1 to 3 | Vaginal yeast
Its most reliable use. Itch and soreness settle within a day or two. Infections that keep returning get a weekly tablet for months instead.
Week 1 | Oral thrush
White patches lift within the week, but finish the course. If thrush keeps coming back, the reason — an inhaled steroid, dentures, dry mouth, diabetes, a suppressed immune system — matters more than the tablet.
Weeks 2 to 4 | Skin folds and trunk
Redness and scaling fade on weekly dosing. Yeast folliculitis often clears here, after months of acne treatment did not. Both return if the skin stays damp.

Side Effects

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A single dose is usually uneventful. Longer courses are where the liver and the drug interactions start to matter.

Common — expected, and they settle

  • Nausea or stomach discomfort
  • Headache
  • Diarrhea
  • Rash Usually mild.

Tell your doctor — worth a call, not an emergency

  • Every other medicine you take Fluconazole interacts with a long list, including some heart, cholesterol and seizure drugs.
  • A rash that is spreading
  • Rising liver enzymes Checked on longer courses.
  • A fluttering or racing heartbeat

Stop and get care

  • A rash that blisters or peels Or sores in the mouth and eyes.
  • Yellowing of the eyes or skin With dark urine or severe tiredness.
  • Fainting, or a fast irregular heartbeat

What to Avoid

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  • Starting it without listing your other medicines: The most important step with fluconazole. The interactions are the main risk, not the drug itself.
  • Repeating a single dose on your own If one tablet did not settle things, it may not be yeast. A second dose without a diagnosis delays finding out.
  • Leaving the fold damp Yeast grows where skin stays warm and wet. Treating the yeast without drying the area sets up the next round.
  • Heavy drinking during a course No direct interaction, but the liver processes this drug and occasional enzyme rises do happen.
  • Treating a chest and back rash as acne If months of acne treatment have not helped a uniform, itchy, small-bump rash, raise yeast folliculitis.

Monitoring

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A short course in a healthy person needs no blood tests. Longer courses, higher doses, or liver or kidney problems may prompt liver and kidney checks.

The interactions are what need watching. Fluconazole slows the liver enzymes that clear many common medicines, so those medicines build up. The main ones are warfarin, where the clotting test can climb; sulfonylurea diabetes tablets such as glipizide and glyburide, where blood sugar can drop too low; some statins, where muscle pain and rarely muscle damage follow; phenytoin; some sedatives; ciclosporin and tacrolimus after a transplant; and several drugs that affect the heart's rhythm.

That last group matters because fluconazole itself can lengthen the QT interval, part of the heart's rhythm. A few combinations are never used, and your prescriber checks before writing it.

Liver enzyme rises are usually mild and serious liver injury is rare, but yellowing skin or eyes, dark urine, or persistent nausea means stop and be seen — as does a spreading rash with blistering or mouth sores, the same day.

If You Stop

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There is no taper. Courses are short; you stop at the end. What happens next depends on why the yeast was there. Yeast lives normally on skin and mucous membranes, so treatment removes an overgrowth rather than the organism. If the conditions that let it overgrow are unchanged — a damp fold, an inhaled steroid used without rinsing, poorly controlled diabetes, a course of antibiotics — it returns. For infections that keep coming back, a planned weekly dose for several months is a recognized approach, then stop and see.

Cost

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Generic fluconazole is cheap and stocked everywhere. The single 150 mg tablet is one of the cheapest prescriptions in dermatology, and in some countries it is sold without a prescription for vaginal yeast infection. Longer courses stay cheap because the tablets are cheap. Off-label weekly use for nails runs many months, so the total adds up, and insurers may not cover it. The liquid suspension for children costs more than tablets.

Ask Your Doctor

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If you take warfarin or another blood thinner: It raises warfarin's effect, and clotting levels may need rechecking.
If you take a statin
Some statins build up, raising the risk of muscle injury, so yours may be paused or switched.
If you take a diabetes tablet
Such as glipizide or glyburide — blood sugar can drop too low.
If you take a heart rhythm medicine
Or a long QT interval. Fluconazole adds to that, and some combinations are avoided.
If you have had a transplant
Ciclosporin and tacrolimus levels can rise and need monitoring.
If you have liver or kidney disease
The dose is often reduced, and liver tests checked.
If you are pregnant or breastfeeding
Planning a pregnancy counts too. Ask the doctor managing your pregnancy; it is usually avoided, and a cream is preferred.
If a rash starts
Blisters, peeling or mouth sores especially. Stop and be seen the same day.

How It Compares

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Itraconazole
The same
another triazole tablet, stronger against a wider range of fungi. More interactions, cannot be used in heart failure, and absorption depends on stomach acid and food.
TerbinafineDiagram: how Terbinafine works in the skin
Terbinafine
Different job
better than fluconazole for nail, scalp and ringworm-type infections. Weaker against yeast, so it is the wrong choice for thrush or Candida.
Ketoconazole shampoo or cream
Different job
the usual partner treatment for yeast folliculitis and for tinea versicolor, often used alongside or instead of a tablet. No body-wide interactions.
Nystatin liquid or lozenges
The same
works only where it touches, which suits mouth thrush and avoids interactions entirely. Needs several doses a day and tastes unpleasant.
Boric acid vaginal suppositories
Different job
used for yeast species that fluconazole does not cover, on a doctor's advice. Not taken by mouth.

Myths

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  • "One tablet cures any yeast problem." One tablet handles simple vaginal yeast. Thrush, folds, folliculitis and nails need longer courses.
  • "Fluconazole treats all fungal infections." It is strongest against yeasts. Ringworm responds better to terbinafine, and some Candida species are naturally resistant.
  • "It is safe with anything because it is only one dose." The risk comes from the enzymes it blocks, not the length of the course. Even one dose can nudge warfarin.
  • "Recurring yeast infections mean poor hygiene." They usually mean antibiotics, diabetes, hormonal changes, a suppressed immune system, or damp skin. Over-washing makes fold problems worse.
  • "If the itching stopped, the course can stop." Symptoms settle before the infection clears. Finish the course.

Questions Patients Ask

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How fast does one tablet work?

Itch and soreness usually ease within a day or two, and most simple cases clear with one dose.

Why did my doctor ask about all my other medicines?

Because it slows the liver enzymes that clear warfarin, some statins and some diabetes tablets. Interactions are the main safety issue.

Can I drink alcohol on it?

No direct interaction. Avoid heavy drinking during a course, since the liver processes the drug.

Why do my yeast infections keep coming back?

Usually something keeps favoring it — antibiotics, hormonal changes, diabetes, an inhaled steroid, or a damp fold. Repeated single doses rarely settle that.

Will it clear my athlete's foot or ringworm?

It can, but terbinafine works better on that family of fungi. Fluconazole is the yeast drug.

Can I take it during pregnancy?

Ask the doctor managing your pregnancy. It is usually avoided, and creams are used instead.

References

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