Ultrasound significantly improves the ability of vitamin C and niacinamide to reduce hyperpigmentation, according to research from Japan.
The researchers noted with frustration that hyperpigmentation and dark spots were tough to treat with skin lightening agents. This is because of the limitations on delivering them through the epidermis. So they decided to find out what would happen if ultrasound was used with a gel containing ascorbyl glucoside (vitamin C) and niacinamide.
The trial on 60 Japanese women with hyperpigmentation over four weeks and the results were assessed by computer analysis and self-perception. The conclusion was that ultrasound together with the vitamin C and niacinamide skin-lightening gel “significantly reduced facial hyperpigmented spots compared with both no treatment and skin-lightening gel.”
Good to know! But scientists don’t stop there as they, of course, want to know why ultrasound helps with penetration of these vitamins and other topically applied active ingredients. In a book on the subject of absorption of topical skin treatments, the authors (Robert Bronaugh and Howard Mabach) speculate that ultrasound’s ability to improve absorption may be due to the way ultrasound interacts with structured lipids in the stratum corneum.
In a useful round-up of various studies, they note that one demonstrated that ultrasound increased the rate of diffusion of oxygen through the skin (of frogs). Other researchers suggest that the (subsensory) vibrations of ultrasound create microscopic bubbles on the surface of the skin and that somehow this increases the skin’s permeability.
Although the mechanism by which ultrasound improves product penetration seems to be undetermined as yet, Bronaugh and Mabach are in no doubt that the effects are palpable and speculate that some day ultrasound will be used rather than needles to deliver medicines such as insulin.