Malassezin

Malassezin is an ingredient derived from Malassezia furfur; a type of yeast found naturally on the surface of human skin. While certain strains of this yeast have been associated with skin conditions including folliculitis, “fungal acne” and dandruff, its derivative yields a much different result.

Recent studies indicate that in addition to providing antioxidant benefits, malassezin interrupts factors that lead to skin discolorations – but in a way that’s different from most traditional methods. Ingredients such as hydroquinone and tranexamic acid are so effective because they interfere with tyrosinase, an enzyme whose overproduction can trigger excess, uneven melanin production, leading to dark spots and patches.

Research so far indicates that malassezin fights skin discolorations by inducing what is known as melanocyte apoptosis – essentially, the programmed death of melanocytes, the cells responsible for producing melanin in skin. While this might sound somewhat bad, this process helps ensure melanin production doesn’t become overactive, potentially helping restore skin’s natural, uniform color.

Clinical studies have found malasseizin in amounts as low as 0.1% effective in minimizing the appearance of discolorations; however, we should note there is no breadth of research yet comparing its effectiveness against other treatments for hyperpigmentation. We also need to learn more about the extent of cell death it causes, and how skin’s antioxidant defense system may control this process. Novel approaches to fading hyperpigmentation for brighter skin are exciting, but time will tell how this particular approach stacks up against the tried-and-true options.

Most familiar brighteners work by slowing tyrosinase, the enzyme that starts melanin production. Malassezin does not — laboratory testing found no tyrosinase-inhibiting activity at all, which is what makes it unusual among tone-evening ingredients.

Instead it binds to the aryl hydrocarbon receptor, a sensor sitting inside skin cells that responds to certain small molecules. In cell studies (Krämer and colleagues, ChemBioChem), switching that receptor on prompted pigment-producing melanocytes to undergo apoptosis — the orderly, programmed self-shutdown that cells use routinely as part of normal turnover.

Biopsy work in a small group of volunteers found a similar pattern in skin: after twice-daily use, epidermal melanin was lower at eight and fourteen weeks, and melanocytes appeared less branched and slightly fewer in number, with no abnormal cells reported.

The same work suggests the effect is not open-ended. By twenty-two weeks — eight weeks after use stopped — melanin measured on biopsy had returned to where it started. All of this is laboratory and biopsy evidence, not a promise about how any individual's skin will look.

Malassezin is a leave-on ingredient, so it belongs in the serum step rather than a cleanser.

• Apply to clean, dry skin before your moisturiser. Most formulas are light serums that sit happily under everything else.
• Twice daily is the pattern used in the research — morning and evening. If your skin is reactive, start once a day and build up.
• Give it eight to fourteen weeks. In the published work, changes in the appearance of pigmentation showed up around the eight and fourteen week marks, not in days.
• Treat it as ongoing rather than a short course. In the research, the appearance of lightening held for about eight weeks after use stopped, while pigment measured on biopsy had returned to baseline by then.
• Wear a broad-spectrum SPF 30 or 50 every morning. Without it, daylight will keep prompting the very pigment you are trying to even out.
• Layer sensibly. No specific clashes have been reported, and it is often formulated with retinol or niacinamide. Still, introduce one new active at a time so you can tell what is doing what.