Reviewed on 9/2/2021

What Is Griseofulvin and How Does It Work?

Griseofulvin is a prescription drug indicated for the treatment of the following ringworm infections: tinea corporis (ringworm of the body), tinea pedis (athlete's foot), tinea cruris (ringworm of the groin and thigh), tinea barbae (barber's itch), tinea capitis (ringworm of the scalp), and tinea unguium (onychomycosis, ringworm of the nails), when caused by one or more of the following genera of fungi: Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Trichophyton interdigitalis, Trichophyton verrucosum, Trichophyton megnini, Trichophyton gallinae, Trichophyton crateriform, Trichophyton sulphureum, Trichophyton schoenleini, Microsporum audouini, Microsporum canis, Microsporum gypseum, and Epidermophyton floccosum

NOTE: Prior to therapy, the type of fungi responsible for the infection should be identified. The use of the drug is not justified in minor or trivial infections which will respond to topical agents alone. Griseofulvin is not effective in the following: bacterial infections, candidiasis (moniliasis), histoplasmosis, actinomycosis, sporotrichosis, chromoblastomycosis, coccidioidomycosis, North American blastomycosis, cryptococcosis (torulosis), tinea versicolor and nocardiosis.

  • Griseofulvin is available under the following different brand names: Grifulvin V and Gris-PEG.

What Are Dosages of Griseofulvin?

Dosages of Griseofulvin:

Adult and Pediatric Dosages:

Oral suspension, microsize

  • 125 mg/5 ml

Tablet, microsize

  • 500 mg (Grifulvin V)

Tablet, ultramicrosize

  • 125 mg (Gris-PEG)
  • 250 mg (Gris-PEG)

Dosage Considerations – Should be Given as Follows:

Tinea Infection

  • Infections affecting skin, body, hair/beard, or nails
  • Microsize
  • Adult:
    • Tinea corporis, cruris, or capitis: 500 mg/day orally
    • Tinea pedis or unguium: 1000 mg/day orally as a single daily dose or divided every 12 hours
  • Pediatric:
    • Children under 2 years old: safety and efficacy not established
    • 11 mg/kg/day orally as a single dose or divided every 12 hours
    • Children 13.6-22.7 kg (30-50 lb): 125-250 mg/day
    • Children over 22.7 kg (over 50 lb): 250-500 mg/day
  • Off-label: 10-20 mg/kg/day divided every 12 hours
  • Ultra-micro-size
  • Adult:
    • Tinea corporis, cruris, or capitis: 375 mg/day orally
    • Tinea pedis or unguium: 250 mg orally every 8 hours
  • Pediatric:
    • 7.3 mg/kg/day orally
    • Children 13.6-22.7 kg (3-50 lb): 82.5-165 mg/day
    • Children over 22.7 kg (over 50 lb): 135-330 mg/day
    • Off-label: 5-15 mg/kg/day orally divided every 12 hours; not to exceed 750 mg/day

Treatment duration – Adult and Pediatric:

Dependent on infection site

  • Tinea corporis: 2-4 weeks
  • Tinea capitalize: 4-6 weeks; maybe up to 8-12 weeks
  • Tinea pedis: 4-8 weeks
  • Tinea unguium: 4-6 months

Dosing considerations:

  • Absorption increased with fatty meals


Rosacea, Acne, Shingles, Covid-19 Rashes: Common Adult Skin Diseases See Slideshow

What Are Side Effects Associated with Using Griseofulvin?

Common side effects of griseofulvin include:

  • abdominal pain
  • chills
  • clay-colored stools
  • confusion, trouble with daily activities
  • dark urine
  • diarrhea
  • dizziness
  • fatigue
  • feeling tired
  • fever
  • flu symptoms
  • flushing (warmth, redness, or tingly feeling)
  • gastrointestinal bleeding
  • headache
  • hives
  • insomnia
  • itching
  • kidney disease
  • liver damage
  • loss of appetite
  • menstrual irregularities
  • mental confusion
  • nausea
  • numbness or tingling in your hands or feet
  • protein in the urine
  • rash
  • reduced white blood cells
  • sensitivity to light
  • severe skin reaction (fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling)
  • sleep problems (insomnia)
  • vomiting
  • white patches or sores inside your mouth or lips
  • yeast infection in the mouth
  • yellowing of the skin or eyes (jaundice)

Rare side effects of griseofulvin include:

  • swelling of the skin
  • drug-induced lupus-like syndrome
  • menstrual irregularities
  • numbness of hands and feet

Postmarketing reports of griseofulvin include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Griseofulvin?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Griseofulvin has no known severe interactions with other drugs.
  • Griseofulvin has serious interactions with 21 different drugs.
  • Griseofulvin has moderate interactions with 112 different drugs.
  • Griseofulvin has minor interactions with 71 different drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Griseofulvin?


This medication contains griseofulvin. Do not take Grifulvin V or Gris-PEG if you are allergic to griseofulvin or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Hypersensitivity
  • Porphyria
  • Hepatocellular failure
  • Pregnancy

Effects of Drug Abuse

  • Avoid using alcohol.

Short-Term Effects

  • See "What Are Side Effects Associated with Using Griseofulvin?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Griseofulvin?"


  • Severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis) and erythema multiforme were reported, some resulting in hospitalization or death; discontinue if severe skin reaction occurs.
  • Elevations in AST, ALT, bilirubin, and jaundice were reported, some resulting in hospitalization or death; discontinue if jaundice occurs.
  • Patients on prolonged therapy with any potent medication should be under close observation; periodic monitoring of organ system function, including renal, hepatic and hematopoietic, should be done.

Pregnancy and Lactation

  • Do not use griseofulvin during pregnancy. The risks involved outweigh the potential benefits. Safer alternatives exist.
  • It is unknown if griseofulvin is excreted in breast milk; avoid use because of the potential to cause tumors (tumorgenicity).


Ringworm is caused by a fungus. See Answer
Medscape. Griseofulvin.
RxList. Gris Peg Monograph.

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