Skin Lightening and a new Brightening Gel from ReLuma
Hyperpigmentation comes down to melanocyte activity. Melanocytes are pigment cells. There are typically between 1000 and 2000 melanocytes per square millimeter of skin and make up about 5% to 10% of the cells in the basal layer of epidermis (incidentally, black and white skins possess the same number of melanocytes). They migrate to the basal layer of the epidermis and the hair matrices; failure to get to those destinations can result in, for example, patchy white spotting of the skin. (You read more on hyperpigmentation here)
The interaction between melanocytes and keratinocytes is critical. Melanin, inside keratinocytes, absorbs harmful UV rays before they can damage the DNA. One role of melanin is to neutralize free radicals and, up to a point, functions like a natural sunscreen. Sun damaged skin has approximately twice as many melanocytes as in unexposed areas. Even so melanocytes decrease with age by as much as 20% every decade or so.
That decrease leads to loss of hair color over time. But, conversely, there is no loss of skin pigmentation with age. In fact, the chronically sun-exposed skin of an older person is usually more pigmented than that of a despite their lower melanocyte density. The theory is that the older melanocytes, after many years of cumulative sun exposure, are much more active. Something like this is happening: exposure to UV-R induces an increase in the production of something called ET-1 by keratinocytes, and this, in turn, stimulates melanocytes to produce melanin.
It’s all pretty complex and there are so many different “pathways” involved in the regulation of melanogenesis, that stimulating or inhibiting more than one of them is probably the only way to succeed in preventing hyperpigmentation. Many recent cosmetic products, however, hone in on one mechanism – the inhibition of tyrosinase. This mostly, if anything, helps prevent future hyperpigmentation.
For fading existing dark spots, alpha arbutin seems to be one of the few safe and effective alternatives to hydroquinone. It also inhibits tyosinase, but a study in China also showed it to fade existing skin damage. Alpha arbutin is in ReLuma’s Brightening Gel, as is vitamin C, which has also been shown to have an inhibitory effect on melagonenis. A recent study found that a combo of 10% ascorbic acid (vitamin C) and 2% phyto acid reduced pigmentation significantly.
But what about the role of ReLuma/Ivitrx’s signature human conditioned media? Well, “melanin production results from strong cellular and molecular connections between all cell populations in the skin, the key players being fibroblasts, keratinocytes, and melanocytes” and melanocytes respond to, amongst other things, UV-R, growth factors and cytokines (source). The human adipose stem cells used by ReLuma are effectively growth factors. ReLuma says that there is an 80% concentration here, but is hedging its bets with a formula that includes a few other approaches.
I've come to the conclusion that the most effective fader is the crude mechanism of exfoliation and products with a hefty dose of glycolic acid can make a difference. ReLuma's Brightening Gel also contains glycolic acid. Plus there's niacinamide, a member of the vitamin B family and a melanin inhibitor. I’ll be testing this Brightening Gel over the coming weeks. In my experience, ReLuma products take a few weeks to kick, so I’ll report back in a month or so.
Ingredients: HASC Conditioned Media (80%), Glycerin, Polysorbate-20, Niacinamide, Aloe Vera extract, Cellulose Gum, Alpha Arbutin, Phenoxyethanol, Glycolic Acid, Grapefruit, Green tea, Licorice extract, Allantoin, Vitamin C (Tetrahexyldecyl Ascorbate).