Griseofulvin

Pronunciation: griz-ee-oh-FUL-vin.

Generic name
griseofulvin
Drug class
Antifungal antibiotic (fungistatic, keratin-binding; derived from a Penicillium species)
Form
Tablet or oral suspension
Route
Oral
Legal status
Prescription-only where currently marketed (confirmed in the United States, United Kingdom, and Australia); withdrawn from the New Zealand market since 2002; current status not independently confirmed for Canada or at EU level in this research round

Supply Rules Vary

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Grisovin (3) (4) · Full directory

What griseofulvin is and how it works

Griseofulvin is an older oral antifungal medicine used to treat dermatophyte (ringworm/tinea) infections of the skin, hair, and nails when topical (skin-applied) antifungal treatment alone is not enough. Taken by mouth, it is absorbed into the body and deposited into newly forming keratin (the protein in skin, hair, and nails), where it stops the fungus growing; the old, infected keratin is then gradually shed and replaced by fungus-free tissue as the body naturally renews these tissues. (1) (2) (6)

Griseofulvin has some genuinely serious, well-established safety boundaries: it must not be used in pregnancy, is contraindicated in porphyria and severe liver disease, and treatment courses are long -- weeks for skin/hair infections, and many months for nail infections. It has also become less commonly available over time: it was withdrawn from the New Zealand market in 2002 in favour of newer antifungals, so availability genuinely varies by country.

Mechanism of action: how griseofulvin works

Griseofulvin is a fungistatic antifungal derived from Penicillium species, active against Trichophyton, Microsporum, and Epidermophyton dermatophytes. After oral absorption it is deposited in keratin precursor cells; as new keratin forms it resists fungal invasion, and the old infected keratin is progressively shed as the tissue naturally turns over -- explaining why treatment courses must span the relevant tissue's full growth cycle (much longer for nails than skin). (2) (1)

What griseofulvin is used for

Dermatophyte (ringworm/tinea) infections of skin, hair, and nails

Used for fungal infections such as tinea corporis (body ringworm), tinea pedis (athlete's foot), tinea cruris (jock itch), tinea barbae (beard ringworm), tinea capitis (scalp ringworm), and tinea unguium/onychomycosis (nail fungus), specifically when topical treatment alone has not been adequate or is not suitable. It is not effective against Candida (yeast) infections or some other fungal organisms. (1) (2)

Before taking griseofulvin

Do not take / not appropriate for

  • Do not take griseofulvin if you are pregnant, or if you might become pregnant within 1 month of stopping treatment -- this is a genuine, serious contraindication, not a general caution. (United Kingdom, United States) (2) (1)
  • Do not take griseofulvin if you have porphyria or severe liver disease. (United Kingdom) (2)
  • Do not take griseofulvin if you have systemic lupus erythematosus (SLE), or a known hypersensitivity to griseofulvin. (United Kingdom) (2)

Tell your clinician about

  • Whether you are pregnant, might become pregnant, or are breastfeeding.
  • Any personal or family history of porphyria, or any liver, kidney, or blood-cell condition, given the monitoring this medicine requires.
  • All other medicines you take, especially hormonal contraceptives, warfarin, ciclosporin, or phenobarbital.
  • Whether you plan to father a child -- men are generally advised to avoid fathering a child for 6 months after finishing treatment.
  • Whether you drink alcohol, given a documented interaction.
(2) (1)

How to take griseofulvin

  • Take after meals -- absorption is improved when taken with (especially fatty) food.
  • Complete the full prescribed course: at least 4 weeks for skin or hair infections, but 6-12 months for nail infections, and generally continued for about 2 weeks after the infection has cleared.
  • Do not stop early just because visible symptoms improve -- the keratin needs time to be replaced, which is why courses are long, especially for nails.
(2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

Contact your prescriber or pharmacist for guidance if you miss a dose, especially given how long treatment courses run. Do not double a dose to make up for a missed one without their advice.

Overdose

Seek urgent medical attention or contact a poison information service if you think you have taken too much griseofulvin, or if you develop severe headache, confusion, or any unusual symptoms. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Headache -- one of the more frequently reported effects.

What to notice: Headache -- one of the more frequently reported effects.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (2) (1)

Gastrointestinal upset: nausea, vomiting, diarrhoea, and general gastric discomfort.

What to notice: Gastrointestinal upset: nausea, vomiting, diarrhoea, and general gastric discomfort.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (2) (1)

Fatigue, dizziness, insomnia, or mental confusion have been reported occasionally.

What to notice: Fatigue, dizziness, insomnia, or mental confusion have been reported occasionally.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Oral thrush has been reported occasionally.

What to notice: Oral thrush has been reported occasionally.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of peripheral neuropathy — high caution

Symptoms: Numbness, tingling, or unusual sensations in the hands or feet.

Action: Contact your prescriber if you notice these symptoms. This has been reported with griseofulvin, particularly with longer treatment durations; most cases reported improved or resolved after treatment ended, but your prescriber needs to assess it. (1)

Signs of liver problems — high caution

Symptoms: Unusual tiredness, loss of appetite, nausea, dark urine, or yellowing of the skin or eyes (jaundice).

Action: Contact your clinician promptly for assessment and liver function testing -- griseofulvin requires periodic monitoring of liver (and kidney and blood-forming) function during treatment, especially if you already have liver disease. (1) (2)

Skin reaction to sunlight (photosensitivity) — high caution

Symptoms: Exaggerated sunburn-like reaction or rash on skin exposed to strong sunlight.

Action: Use sun protection and tell your clinician if you notice an unusual skin reaction to sunlight while taking griseofulvin. (2)

Signs of a serious allergic reaction — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives.

Action: Seek emergency medical help immediately. (2)

Interactions

  • Reduces the effectiveness of hormonal (oral) contraceptives -- an additional or alternative contraceptive method is generally needed during treatment and for a period afterward; discuss this with your prescriber. (2)
  • Reduces the effectiveness of warfarin -- blood-clotting (INR) monitoring and dose adjustment by your prescriber may be needed. (2)
  • Reduces the effectiveness of ciclosporin. (2)
  • Phenobarbital can reduce how well griseofulvin is absorbed. (2)
  • Alcohol has been reported to interact with griseofulvin; discuss alcohol use with your prescriber. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Contraindicated. Griseofulvin should not be used in pregnancy, or by women intending to become pregnant within 1 month of stopping treatment, based on animal studies showing teratogenic (birth-defect) effects and an absence of reassuring human safety data. (1) (2) (3) (4) (5) (6)

Breastfeeding

Specific breastfeeding safety data were not detailed in the sources reviewed for this dossier; discuss with your clinician given the pregnancy contraindication and general caution with this medicine. (1) (2) (3) (4) (5) (6)

Children

Used in children at a weight-based dose (around 10 mg/kg/day in divided doses per the UK source reviewed); paediatric use should be guided by a prescriber. (1) (2) (3) (4) (5) (6)

Elderly

No specific age-based dose adjustment is described in the sources reviewed, though the same organ-function monitoring applies. (1) (2) (3) (4) (5) (6)

Hepatic_impairment

Contraindicated in severe liver disease; periodic liver function monitoring is required during treatment more broadly. (1) (2) (3) (4) (5) (6)

Renal_impairment

Periodic monitoring of renal function is required during treatment; no specific dose-adjustment schedule was detailed in the sources reviewed. (1) (2) (3) (4) (5) (6)

Male_fertility

Men are generally advised not to father a child for 6 months after completing treatment, per the UK source reviewed. (1) (2) (3) (4) (5) (6)

Source_ids

UK-EMC-GRISEOFULVIN-SMPC-2026,US-DAILYMED-GRISEOFULVIN-2026 (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Confirmation of pregnancy status and contraception plan
  • Baseline liver, kidney, and blood-count assessment where clinically indicated
  • Review of other medicines for interactions (hormonal contraceptives, warfarin, ciclosporin, phenobarbital)

During treatment

  • Periodic monitoring of renal, hepatic, and haemopoietic (blood-forming) function, as recommended in the US label reviewed.
  • Watching for peripheral neuropathy symptoms, photosensitivity reactions, and treatment response over the (often long) course.
(1) (2)

Storage

Store at room temperature, away from moisture and direct light, out of reach of children, following the specific product's label since formulations vary.

Professional information

Clinician-facing context only, sourced from the current UK SmPC and US prescribing information; verify against the current full label and local availability before prescribing, given this medicine's country-variable current market status.

United Kingdom (broadly consistent with US/Australian sourced dosing pattern)

Indication: Dermatophyte infections of skin, hair, and nails

Dose summary: Adults 500-1000 mg daily (minimum 10 mg/kg/day), after meals; children ~10 mg/kg/day in divided doses; at least 4 weeks for skin/hair, 6-12 months for nails, continued ~2 weeks past clinical clearance.

Renal context: Periodic renal function monitoring recommended; no specific dose-adjustment schedule detailed in the sources reviewed. (2)

Mechanism of action

Hepatic guidance

Contraindicated in severe liver disease/porphyria; periodic hepatic function monitoring recommended during treatment more broadly.

Overdose note

No specific antidote described in the sources reviewed; manage with supportive care and contact a poison information service for guidance. (2) (1)

Frequently asked questions

Is griseofulvin available in the US, UK, EU, Canada, Australia, and New Zealand?

Availability genuinely differs by country. It is confirmed currently available in the United States, United Kingdom, and Australia (as Grisovin, PBS-subsidised). It was withdrawn from the New Zealand market in 2002, superseded by newer antifungals. Its current marketed status in Canada and at the EU level could not be independently confirmed in this research round -- always check with a local pharmacist or prescriber for current availability. (1) (2) (3) (5) (6)

Why does nail-fungus treatment with griseofulvin take so much longer than skin treatment?

Griseofulvin works by being deposited into newly formed keratin, which then has to grow out and replace the old, infected keratin as the body naturally sheds it. Nails grow much more slowly than skin, so clearing a nail infection this way can take 6 to 12 months, compared with about 4 weeks or more for skin or hair infections. (2)

Why is griseofulvin contraindicated in pregnancy?

Griseofulvin has shown teratogenic (birth-defect-causing) effects in animal studies, and there is no reassuring human pregnancy safety data. Because of this, it should not be used in pregnancy or by women intending to become pregnant within 1 month of stopping treatment, and men are generally advised not to father a child for 6 months after finishing treatment. (2)

What is the mechanism of action of griseofulvin?

Griseofulvin is a fungistatic antifungal derived from Penicillium species, active against Trichophyton, Microsporum, and Epidermophyton dermatophytes. After oral absorption it is deposited in keratin precursor cells; as new keratin forms it resists fungal invasion, and the old infected keratin is progressively shed as the tissue naturally turns over -- explaining why treatment courses must span the relevant tissue's full growth cycle (much longer for nails than skin). (2) (1)

What is the generic name of Griseofulvin?

The generic name is griseofulvin. (1) (2)

What class of drug is griseofulvin?

Griseofulvin is classed as: Antifungal antibiotic (fungistatic, keratin-binding; derived from a Penicillium species). (1) (2)

References

  1. GRISEOFULVIN tablet / suspension -- prescribing informationU.S. Food and Drug Administration / DailyMed · United States · accessed 2026-07-30 · source 1
  2. Griseofulvin 500 mg Tablets -- Summary of Product Characteristicselectronic Medicines Compendium (UK) · United Kingdom · accessed 2026-07-30 · source 2
  3. Grisovin (griseofulvin) -- medicine informationHealthdirect Australia (government-funded consumer health service, citing TGA/PBS data) · Australia · accessed 2026-07-30 · source 3
  4. Grisovin -- Medicine Finder entryAustralian Commission on Safety and Quality in Health Care · Australia · accessed 2026-07-30 · source 4
  5. GRISOVIN FP TAB 250MG -- Drug Product Database entry (DIN 00012254)Health Canada, Drug Product Database · Canada · dated 1996-09-10 · accessed 2026-07-30 · source 5
  6. Griseofulvin -- clinical reference pageDermNet New Zealand (clinical dermatology reference, New Zealand) · New Zealand · accessed 2026-07-30 · source 6

Brand names by country

Single-ingredient griseofulvin names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Ultramicrosize Griseofulvin250 mg, 125 mg, 165 mg · chartwell rx, llc.
  • Griseofulvin MICROSIZE500 mg · chartwell rx, llc.
  • grisofulvin125 mg/5mL · cipla usa inc.

United Kingdom

  • Griseofulvin (generic tablet) (2)current licensed product · 125 mg, 500 mg · See UK EMC SmPC (products 12894/12895)

Canada

  • Grisovin FP (historical; DIN 00012254) (5)administratively cancelled since 1996 current availability not confirmed · 250 mg (historical record) · Glaxo Canada Inc (historical record; product status cancelled post-market 1996-09-10)

Australia

  • Grisovin (3) (4)current pbs subsidised product · 125 mg, 500 mg · See TGA/PBS listing via Healthdirect Australia

New Zealand

  • Withdrawn from the New Zealand market in 2002 (6)withdrawn 2002 not currently marketed · Not applicable
View brands in additional countries.

European Union

No specific EU-level product record independently confirmed in this research round