Lemon hydrosol, an ingredient against dark spots?

The brown spots form as a result of melanin accumulation in the skin. This dark brown pigment is an essential element that plays a protective role against UV rays. The production of melanin is triggered by exposure to sunlight. Indeed, UV rays act on tyrosine, an amino acid, and, thanks to the enzyme tyrosinase, trigger a cascade of reactions leading to the synthesis of melanin. This process is melanogenesis.

Brown spots gradually form throughout life, as exposure to the sun is repeated. Their shape and size can vary. Brown spots are primarily located on the most sensitive and exposed parts of the body, such as the face, neck, shoulders, arms and legs. They frequently appear around the age of forty, but can also emerge earlier.

Although the sun plays a significant role in the development of brown spots, other factors can also contribute to this phenomenon. Indeed, smoking, pollution, or an unbalanced diet can lead to a oxidative stress within the body's cells, that is, the production of free radicals. These reactive oxygen species then cause damage to the DNA and accelerate skin ageing.

Finally, the melasma is a type of brown spot directly linked to a hormonal change. During pregnancy, the level of oestrogen in the body significantly increases, which induces an overproduction of melanin.

Lemon hydrosol is often considered an interesting ingredient for eliminating brown spots. Indeed, it is believed to possess lightening and depigmenting properties. However, it should be noted that to date, no scientific study has demonstrated that lemon hydrosol has a visible effect on brown spots.

However, traces of vitamin C can be found in lemon water, a compound known for its brightening virtues. This molecule can indeed inhibit tyrosinase, the enzyme responsible for the conversion of tyrosine into melanin. Moreover, vitamin C is an antioxidant, capable of eliminating free radicals from the body. Its mechanism of action relies on a donation of its electrons, allowing it to stabilise and neutralise reactive species, capable of stimulating melanogenesis. Thus, vitamin C has a dual activity: preventive due to its antioxidant properties and corrective due to its brightening effects.

However, it is important to note that the amount of vitamin C contained in a lemon hydrosol is very low. Therefore, we cannot assert that its concentration in lemon water is sufficient to induce brightening and antioxidant effects. It is thus recommended to combine it with a treatment containing more vitamin C to achieve results.

One must not confuse lemon juice with lemon hydrosol. The former is highly acidic and extremely photosensitising, due to its high concentration of furocoumarins. On the other hand, lemon water is a gentle treatment suitable even for pregnant or breastfeeding women and young children.

Typology has incorporated thelemon hydrosol (INCI name: Citrus Limon (Lemon) Fruit Water) into two facial care products so that it can provide a complementary action to the other active ingredients present. These products help to maintain a radiant complexion.

• The hyperpigmentation serum contains, in addition to lemon hydrosol, arbutin acid, an active ingredient known for its depigmenting action. Daily application of this serum helps to reduce brown spots and delay their appearance.

• The antioxidant face cream contains lemon extract combined with a high percentage of vitamin C (5%) and helps to combat oxidation processes and even out the complexion.

• FEILY A. & al. Skin wound healing and phytomedicine: a review. Skin pharmacology and physiology (2014).