Oral and topical L-phenylalanine, clobetasol propionate, and UVA/sunlight--a new study for the treatment of vitiligo

J Drugs Dermatol. 2002 Sep;1(2):127-31.


Background: Vitiligo is a hypopigmented skin condition that usually requires a combination of treatment options.

Aim: To demonstrate the effectiveness of topical and oral L-phenylalanine in combination with light plus 0.025% clobetasol propionate at night.

Patients and methods: We have performed an open trial on a group of 70 patients with evolutive vitiligo. Participants were treated with oral (100 mg/Kg/day) and topical (gel at 10%) L-phenylalanine, exposed to sunlight (spring-summer) or UVA lamps (autumn-winter), and given 0.025% clobetasol propionate at night. All patients were revisited every 6 months while in the study, with a maximum of 4 revisits. Biochemical studies were performed at the beginning of the treatment and at each revisit.

Results: Overall, 90.9% of participants showed improvement, with 68.5% of patients achieving an improvement of 75% or more. This 75% improvement rate was reached 87.9% of the time on the face, 60.4% on the trunk, and 54.6% on the limbs. However, there was a moderate response to the treatment in patients with focal and segmental vitiligo. There was a slight additional improvement in patients receiving UVA lamp light. No biochemical abnormalities were found in any patients.

Conclusion: L-phenylalanine in combination with 0.025% clobetasol propionate and sunlight during sunny months or UVA lamps in winter, appears to improve evolutive vitiligo without side effects, and therefore is especially recommended on the face or for children.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Administration, Oral
  • Administration, Topical
  • Adolescent
  • Adult
  • Anti-Inflammatory Agents / administration & dosage
  • Anti-Inflammatory Agents / therapeutic use*
  • Clobetasol / administration & dosage
  • Clobetasol / therapeutic use*
  • Female
  • Glucocorticoids
  • Humans
  • Male
  • PUVA Therapy / methods*
  • Phenylalanine / administration & dosage
  • Phenylalanine / blood
  • Phenylalanine / therapeutic use*
  • Treatment Outcome
  • Vitiligo / drug therapy*


  • Anti-Inflammatory Agents
  • Glucocorticoids
  • Phenylalanine
  • Clobetasol