DLPA Research

Our discussion focuses on L-phenylalanine, Polypodium leucotomos, khellin, Ginkgo biloba, and vitamins and minerals... used as monotherapy or in combination with other treatments for the management of vitiligo.

• Narrative review of alternative systemic vitiligo treatments including L-phenylalanine
• Summarizes proposed mechanism (melanin-synthesis substrate) and supportive but limited evidence with UVA
• Does not address mood or pain indications

L-Phe may have a place in the treatment of vitiligo and its role merits further investigation.

• Open trial (149 patients, 18 months) plus a small double-blind trial (32 patients, 6 months) of oral L-phenylalanine plus UVA
• Repigmentation up to 77% (open) and 60% (double-blind) was observed
• Higher L-Phe doses did not improve results; optimal dose appeared below 50 mg/kg/day

It is concluded that DL-phenylalanine might have substantial antidepresant properties. However, certain methodological considerations still warrant a careful interpretation.

• 40 depressed patients randomized to DL-phenylalanine (150-200 mg/day) or imipramine for 30 days; 27 completed
• No statistically significant difference between DLPA and imipramine on the Hamilton Depression Scale
• No placebo arm, so an absolute antidepressant effect cannot be established

In the author's clinical experience, concurrent treatment with DL-phenylalanine (DLPA) often appears to potentiate pain relief and also ease depression in patients receiving opiates for chronic non-malignant pain.

• Hypothesis/mechanism paper, not a controlled trial
• Proposes D-phenylalanine acts as an enkephalinase inhibitor to prolong endorphin/enkephalin action
• Based on clinical impression rather than randomized data