What is the recommended dose of isotretinoin for severe acne?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 23, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The recommended dose of isotretinoin for severe acne is typically 0.5 to 1 mg/kg of body weight per day, with a goal cumulative dose between 120 and 150 mg/kg, as this has been shown to be effective in reducing relapse rates 1. When initiating treatment, a lower dose of 0.5 mg/kg/day is often started and may be increased after a few weeks if tolerated well. For example, a 70 kg person might take 35-70 mg daily. Key considerations for treatment include:

  • Taking isotretinoin with food to enhance absorption, as it is highly lipophilic 1
  • Monthly monitoring of liver enzymes and lipids, as these can be affected by the medication 1
  • Absolute avoidance of pregnancy due to severe birth defect risks
  • Management of common side effects such as dry lips, skin, and eyes with moisturizers and eye drops Treatment may be extended if the response is inadequate, or a second course may be considered after a 2-month break if acne recurs after completing the initial treatment. Some studies suggest that higher cumulative doses, such as 220 mg/kg or more, may result in lower relapse rates, but this requires further confirmation 1. It is also important to note that younger age at initial treatment and male gender are associated with an increased risk of relapse, and that nearly 80% of patients under 16 years of age may require a second course of therapy within 2 years after completing the first course of isotretinoin 1.

From the FDA Drug Label

The recommended dosage range for isotretinoin capsules is 0.5 to 1 mg/kg/day given in two divided doses with food for 15 to 20 weeks. Adult patients whose disease is very severe with scarring or is primarily manifested on the trunk may require dose adjustments up to 2 mg/kg/day, as tolerated.

The recommended dose of isotretinoin for severe acne is 0.5 to 1 mg/kg/day given in two divided doses with food for 15 to 20 weeks. However, for adult patients with very severe disease, the dose may be adjusted up to 2 mg/kg/day as tolerated 2.

  • The dose may be adjusted according to response of the disease and/or the appearance of clinical side effects.
  • It is essential to take isotretinoin capsules with food to ensure adequate absorption.
  • The safety of once daily dosing with isotretinoin capsules has not been established, and it is not recommended.

From the Research

Recommended Dose of Isotretinoin for Severe Acne

The recommended dose of isotretinoin for severe acne varies, but several studies provide guidance on effective dosing regimens.

  • The standard dose of isotretinoin is 0.5-1 mg/kg/day for 4 months with a total dose of 120-140 mg/kg/day 3.
  • Daily doses between 0.1 and 0.3 mg/kg can be recommended for more than 6 months due to the occurrence of fewer side effects and more economical concerns 3.
  • High-dose isotretinoin (>1.3 mg/kg/day) has been shown to be safe and effective for severe nodulocystic acne, with a cumulative total dose of 290 mg/kg 4.
  • Low-dose isotretinoin (0.2-0.4 mg/kg/day) has been found to be effective for moderate inflammatory acne, with fewer side effects and reduced risk of acne flares 5.

Considerations for Dosing Regimens

When determining the appropriate dose of isotretinoin, several factors should be considered, including:

  • Severity of acne: Higher doses may be necessary for more severe cases of acne 4, 6.
  • Duration of treatment: Longer treatment durations may be necessary for lower doses 3, 5.
  • Side effects: Lower doses may be recommended to minimize side effects 3, 7, 5.
  • Economic concerns: Lower doses may be more economical than higher doses 3, 7, 5.

Specific Dosing Regimens

Several studies have investigated specific dosing regimens for isotretinoin, including:

  • 0.5-1 mg/kg/day for 4 months with a total dose of 120-140 mg/kg/day 3.
  • 1.3 mg/kg/day or greater for 5-6 months with a cumulative total dose of 290 mg/kg 4.
  • 20 mg/day (approximately 0.3-0.4 mg/kg/day) for 3 months 7.
  • 0.2-0.4 mg/kg/day until acne recovery and independent of cumulative dose 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.