Cosmeceuticals are cosmetic-pharmaceutical hybrids commonly used to improve hyperpigmentation. Hyperpigmentation is generally difficult to treat because the older the hyperpigmentation, the harder it is to remove it. For lightening hyperpigmentation, it is necessary to use skin lightening agents. The active lightening ingredients selectively act on the hyperactive cells that produce melanin (melanocytes) and inhibit key steps in melanin synthesis.
The active lightening ingredients act on different stages of melanin synthesis. The lightening ingredients can affect melanin before melanin synthesis, during melanin synthesis and after the synthesis itself.
Lightening ingredients that directly affect melanin synthesis
Some lightening ingredients act directly on melanin synthesis by inhibiting the tyrosinase enzyme. This enzyme represents a major step in melanin synthesis. By inhibiting this enzyme, it prevents melanin from being synthesized, which is advantageous especially in hyperpigmentations where melanin content is already so high.
Hydroquinone is considered the gold standard for the treatment of hyperpigmentation. It works by inhibiting melanin synthesis by inhibiting the tyrosinase enzyme. In melanin-producing cells, it inhibits DNA synthesis and causes changes in the production of these cells. It causes selective damage, meaning that it only works in hyperactive sites (hyperpigmentation).
Hydroquinone preparations are effective at concentrations between 2-4%. Clinical studies report excellent effects caused by 2% hydroquinone. Higher concentrations are more effective, but they can cause irritation. It can be safely combined with retinoids and steroids.
The Food and Drug Administration (FDA) has issued a ban on bleaching agents containing hydroquinone. The ban came as studies have shown that oral ingestion caused DNA damage. This carcinogenic effect has raised concerns about its use. However, it should be borne in mind that these studies were based on oral doses and there were no clinical studies or cases of skin cancer or internal malignancy associated with topical use.
Kojic acid is a natural product that comes from some types of fungi. Itreduces hyperpigmentation by inhibiting tyrosinase production and is also a powerful antioxidant. Kojic acid is used in concentrations of 1-4%.
It is rarely used as a standalone whitening ingredient. In the studies, kojic acid was combined with glycolic acid or with vitamin C. In both cases, it showed good whitening effects on melasma, but the product needed to be applied longer than hydroquinone to reach effects. It can cause side effects such as erythema, hypersensitivity and contact dermatitis.
Azelaic acid inhibits the enzyme tyrosinase. It is one of the most selective active lightening ingredients, which means that it works exclusively on hyperpigmentation, but not on parts of the skin where there is no hyperpigmentation. It is effective in treating melasma, post-inflammatory hyperpigmentation and lentigas. Topically applied azelaic acid is effective in concentrations between 15-20%. It is one of the active lightening agents that shows the least side effects, with the exception of mild transient erythema.
Arbutin is one of the most commonly prescribed means of lightening and eliminating pigmentation in the world. Arbutin, a derivative of hydroquinone, is a natural plant compound found in the dried leaves of various plant species. Arbutin inhibits tyrosinase activity and inhibits the maturation of melanosomes.
There are practically no clinical studies demonstrating the effectiveness of arbutin in eliminating hyperpigmentation. Several studies have shown that arbutin is less effective than kojic acid in eliminating hyperpigmentation.
Deoxyarbutin is a synthesized arbutin derivative used topically. Studies have shown that topically applied deoxyarbutin shows effect on skin lightening, while being safer to use than hydroquinone.
Other ingredients that affect melanin during its synthesis: alloesin, ellagic acid, resveratrol, licorice extract, mulberry extract.
Lightening ingredients that have antioxidant properties
In our post about hyperpigmentation, we mentioned that UV radiation can make hyperpigmentation even worse. Namely, unprotected exposure to UV radiation causes a greater synthesis of melanin in the skin. As a result, more melanin is also synthesized in hyperpigmented sites, which make them look even darker.
Antioxidants work by preventing reactive oxygen compounds from contacting melanin and oxidizing it to a darker form.
Vitamin C is probably the most famous ingredient on the Cosmedoc.si blog. Ascorbic acid interferes with the various steps of melanin formation. Most importantly, it destroys free radicals to prevent their multiplication, while interacting with copper ions in the tyrosinase enzyme and reducing the intermediate stages of melanin synthesis. Ascorbic acid is already known to be very unstable and it penetrates the skin very poorly, so it is important to choose more stable vitamin C derivatives.
Thioctic acid (a-lipoic acid) also has effects on the brightening of pigment spots. The most important effect of lipoic acid is that it acts photoprotective. This means that it prevents photo-damage (hyperpigmentation).
Lightening ingredients that reduce melanosome transmission
This group of brightening ingredients works to reduce the transmission of melanosomes. Melanosomes are organelles in which melanin travels to the active site. So the smaller the melanosome transmission, the less pigmentation will be. This group includes ingredients such as niacinamide, lecithin, soybean extract.
Compounds that indirectly affect the skin’s lightening by accelerating its regeneration
This group includes cosmetically active ingredients that do not directly affect any of the stages of melanin synthesis. These include ingredients that stimulate cell renewal and thus trigger the removal of skin cells that contain a lot of melanin. Cosmetically active ingredients that can diffuse melanin pigment or accelerate skin exfoliation that can cause skin lightening are the alpha and beta-hydroxy acids, retinoic acid (tretinoin), free fatty acids and retinoic acid.
The visible effects of lightening hyperpigmentation take time
Most of these active lightening agents take time to effect. Lightening pigment spots requires time and constant use of lightening agents. It is imperative that you constantly protect yourself from UV light, as you will be protected from the formation of new pigment spots.
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- Briganti, S., Camera, E., & Picardo, M. (2003). Chemical and Instrumental Approaches to Treat Hyperpigmentation. Pigment Cell Research, 16(2), 101–110.
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- Smit, N., Vicanova, J., & Pavel, S. (2009). The hunt for natural skin whitening agents. International journal of molecular sciences, 10(12), 5326–5349.
- Desai S. R. (2014). Hyperpigmentation therapy: a review. The Journal of clinical and aesthetic dermatology, 7(8), 13–17.