Treatment with lightening substances for dark circles
Often the signs of aging are more evident in the periorbital area, including wrinkles and dark circles that determine a typical and unsightly "tired look".
Focusing on the "blemish" dark circles ", many therapies are available to solve or at least mitigate this condition: considering, however, that the underlying causes of dark circles are many, effective and complete resolution is not always possible.
In general, treatments with depigmenting agents (lightening substances) must be carried out for many months before obtaining cosmetic benefits, and these products are often burdened with heavy side effects, which make their use contraindicated, especially in such a delicate area as the eye contour.
How depigmenters work
The action mechanisms of these substances can be summarized as follows:
- Inhibition of tyrosine activity
- Inhibition of DNA synthesis in the hyperactivity of melanocytes
- Reduction of the melanin content in the epidermis
- Thickening of the granular layer of the epidermis
Which ones are they?
Among these substances that interfere with the melanin pigmentation processes, the following are mentioned:
- HYDROQUINONE: it is considered the most effective "whitening" agent and is still used today to treat hyperpigmentation problems. In fact, it inhibits the synthesis of DNA and RNA, and induces the degradation of melanosomes and the destruction of melanocytes. Already in 1975 two scientists, Dr. Kilgman and Dr. Willis, carried out a first study to evaluate the effectiveness of hydroquinone: after 5-7 weeks of treatment the first positive results were obtained, although it should not be forgotten, however, that the treatment should be prolonged from three months up to a year. The experiment was not carried out using only this cosmetic ingredient (5%), but also 0.1% tretinonine and 0.1% dexamethasone were used. The problem is that the mix of these products had side effects. including erythema, peeling, irritation and contact dermatitis.
- Hydroquinone has multiple side effects, such as skin irritation, dermatitis, cytotoxicity, permanent hypomelanosis or amelanosis. The poor safety of use of the compound has led the European Commission to ban the use of hydroquinone in cosmetic products, limiting its use. as a skin lightener to the prescriptions of doctors and dermatologists.
- RETINOIC ACID: currently, it is believed that a concentration of retinoic acid ranging from 0.01% to 1% reduces pigmentation by inhibiting the transcription of the transferase, leading to the thickening of the granular layer of the epidermis. The number of melanocytes is apparently unchanged, but the damage to them is evident. Retinoic acid must be applied with longer treatments than hydroquinone; significant bleaching occurs after 24 weeks, although side effects similar to the previous depigmenting agent have been reported: peeling and stinging.
- Retinoids (including retinoic acid, not allowed in cosmetology) are considered compounds with medium / deep action, therefore their use is mainly linked to the outpatient setting; they too can be irritating.
- AZELAIC ACID: it is a dicarboxylic acid usually used in the treatment of melasma (facial hypermelanosis that presents itself with a brown color: it is a typical problem of women, especially those who often expose themselves to the sun, and is used to reduce the freckles left by " acne, to combat hair loss and papulopustular rosacea. It has anti-inflammatory, comedolytic, antibacterial and low toxicity properties. Despite this, its use in cosmetics is forbidden because it is irritating.
- COGIC ACID: kojik acid is a natural substance produced by fungi of the genus Aspergillus (whose Japanese name is koji) and is a by-product of the rice fermentation process. It is used in foods and cosmetics to change the color of substances: for this reason it is considered a depigmenting and lightening agent. On the skin, it inhibits the synthesis of melanin and is used in the treatment of melasma or chloasma (a disorder that has typical dark spots due to a change in hormones: pregnant women often suffer from this problem).
Kojic acid and azelaic acid are allowed but cases of dermatitis, contact allergies and sensitization have been reported after their use.
Due to the various factors that cause dark circles, it is essential to identify the triggering cause before starting any treatment: for example, if the shading in the lower eyelid is due solely to "excessive pigmentation, then the melanin deposited can be removed with topical treatment. through bleaching agents; if, on the other hand, the dark circles are caused by swelling induced by a pathology or in any case by an "allergy," the imperfection certainly cannot be treated with these substances. In any case, specific treatments are needed for the periocular area taking into account that the eye contour area has a much thinner and more permeable skin than the rest of the face. It is good to prefer safe molecules able to modulate the process of melanogenesis in a minimally invasive and reversible way, such as ellagic acid, licorice extract or niacinamide.