Hydroquinone: what is it for?

Hydroquinone It is a chemical that is used in cosmetics for depigmenting treatments. It is used, primarily, to lighten especially dark spots on the skin.

There are products with different concentrations of hydroquinone in its composition. The higher the concentration, the stronger the depigmenting action.

Mechanism of action: how does hydroquinone exert its effect?

Melanin is the substance responsible for skin pigmentation, so hydroquinone will act on it. Hydroquinone exerts its action blocking the production of melanin and increasing the degradation of the cells that store melanin.

The blocking of melanin production is carried out by the inhibition of tyrosinase, enzyme that converts tyrosine into melanin. In addition, it alters the structure of melanosomes causing it to increase its degradation or decrease its production. The result of hydroquinone treatment is a much softer skin with a unified tone.

What is it indicated for?

Hydroquinone It is indicated to treat skin hyperpigmentations such as melasma, chloasma or lentigos. Lentigos are a fairly frequent type of spot, which appears due to chronic sun exposure and is usually observed after summer.

There are different alternatives and treatments depending on the type of skin spot. Hydroquinone is one of them; However, it is important for the professional to determine the most appropriate option in each case.

When you are exposed to ultraviolet radiation, the body detects it as an aggression and defends itself by increasing the production of melanin. As the studies show, the increase in melanin can cause skin spots, being more frequent in more exposed areas, such as in the face.

There are several causes that favor the appearance of spots, but the most frequent is sun exposure. Although solar radiation is a determining factor, it is not the only one; There are other factors involved in the appearance of spots, such as:

  • Skin phototype: they are more frequent in light skin, phototypes I or II.
  • Medicines: Some drugs, such as contraceptives, are photosensitive and can cause skin blemishes.
  • Pregnancy.
  • Tobacco consumption.
  • Genetics and age.
  • Previous skin lesions.

Discover: 3 treatments to reduce melasma spots

How is hydroquinone used?

This compound can be used anywhere on the body. That has some spot that you want to clear up. However, you have to be careful with eyes and mucous membranes.

It is applied at night on the area to be treated, which should not be exposed to the sun without sunscreen. In case you have sensitive skin, it is advisable to do the sensitivity test before using the product.

Hydroquinone interferes only in the formation of new melanin, so depigmenting effect is not immediate and several weeks have to pass to see its benefits on the skin.

In addition, the effect of hydroquinone is temporary. This is because the production of melanin is reactivated when the treatment is interrupted. However, depigmentation can be maintained between 2 and 6 months after the end of treatment.

What are the adverse reactions it can produce?

Between the most frequent complications which can cause the use of hydroquinone, are:

  • Irritant contact dermatitis.
  • Redness of the skin.
  • Allergy to the component.
  • Burning sensation

However, some reactions may also occur in some people, such as blisters, swelling of the skin or tongue, shortness of breath and chest pain. Further, hydroquinone is photosensitive, which means that, with exposure to sunlight, it can cause other spots and make the skin's appearance even worse.

Other side effects are related to the application of the cream for prolonged periods, such as loss of elasticity in the skin or discoloration of the nails. In addition, prolonged use can produce an excess of pigment, which is known as ocronosis. It is a dark blue spot, almost irreversible and very difficult to remove.

There is also the risk of developing product allergy. To know if you are sensitive to hydroquinone, it is convenient that you apply it previously in a small area of ​​the skin. Although a slight redness is considered normal, if signs of an allergic reaction appear you should discontinue its use.

Also read: What are photosensitive medications?


It is convenient to use the depigmenting product on a regular basis and combine it with the photoprotector specific to each case. In this way, the results obtained with the treatment will be much better and more durable. Do not forget to consult with the specialist if this is the most appropriate treatment for you.