Phytodynamic therapy for acne and age spots
Photodynamic therapy (PDT) is mostly used as a medical treatment for precancerous or cancerous cells. It uses a drug (typically a gel) that becomes activated by light exposure. The result is an activated oxygen molecule that can destroy nearby cells. PDT essentially has three steps. First, a light-sensitizing liquid, cream, or intravenous drug (photosensitizer) is applied or administered. Second, there is an incubation period of minutes to days (depending on what is being treated). Finally, the target tissue is exposed to a specific wavelength of light that then activates the photosensitizing medication. PDT using a drug called Levulan and a proprietary blue light is currently FDA approved for the treatment of skin precancers called actinic keratosis (rough scaly spots generally on sun-exposed skin).
PDT is also known as "ALA/PDT treatment" or "Super Blue Light." It has been referred to as a "super photo facial" when the photosensitizer is used with a machine called intense pulsed light or IPL. Sun damage, fine lines, and blotchy pigmentation may also be improved. PDT also has been shown to help decrease the appearance of enlarged pores and reduce oil glands, effectively treating stubborn acne and rosacea, while improving the appearance of some small superficial acne scars.
Although acne and rosacea do appear to respond well to PDT and require only a 30-minute incubation period, I've seen reports that PDT doesn't work so well for hyperpigmentation. Still, if you have age spots, PDT is worth keeping an eye on as the technology seems to be continuously evolving,