PDT, topical retinoid, TCA chemical peel and laser resurfacing can all stimulate collagen production

Photodynamic therapy (PDT) involves application of Levulan for a specified duration followed by exposure to the blue light as prescribed by your board-certified dermatologist. Its major effect on the skin is the photochemical reaction where precancerous lesions get preferentially inflamed and sloughed off. Collagen stimulation is a nice bonus, as confirmed by molecular markers as published in the study. However, one may see equal if not greater collagen stimulation over a period of time from regular application of topical retinoid such as Retin-A or Tazorac, TCA chemical peel and/or fractional CO2 laser resurfacing.