Belongs to the alpha-hydroxy acids, AHAs and it is the smallest size molecule. Therefore, has better skin penetration. It is actually a chemical exfoliant. It is water-soluble.

Benefits

Eliminates the external layer of the dead cells and oils of the skin. It breaks down the bonds between dead cells and in this way facilitates their elimination.

Can reduce sun damage which means that acts against dark spot and hyperpigmentation.

May boost collagen production according to some studies.

Can be used to treat acne although salicylic acid is a better option for acne-prone skin.

Improves skin texture.

Can inhibit the production of melanin according to some studies.

It is also used by the dermatologists in office, at higher concentrations, for the melasma treatment.

Who should avoid the use of glycolic acid?

Those with very sensitive, dry or dehydrated skin because GA can be very irritating.

Individuals with sunburn, dry or already irritated skin.

Frequency of use

If the face cleanser contains GA,  it is claimed that it can be used daily. However, I think it is not reasonable. Although the concentration is lower than in an essence or toner, it may be irritating and finally harm your skin barrier. Always prefer a mild cleanser and use another product with GA once or twice a week. Daily use will strip the skin of its natural oils, the skin will have to produce more to replace those eliminated and eventually may lead to breakouts.

Exfoliation is beneficial when it is done properly. Otherwise, may have undesirable effects.

Precautions- Ingredients that cannot be combined with glycolic acid

Lactic acid. Both are potent exfoliators and their use can cause irritation, redness, sensitivity, flaky or burning skin.

Vitamin C, to avoid skin irritation.

Retinoids for the same reason.

Peptides. The acidic pH will reduce the effectiveness of the peptides.

Salicylic acid. Better use them on alternate days or one of them. Otherwise, use a product specifically formulated by a cosmetic brand.

The skin after the use of GA is photosensitive (as it is generally after exfoliation). That’s why it has to be applied in the evening skincare routine. Don’t neglect your sunscreen broad spectrum SPF50 in the morning .

Always do a patch test.

Start with a lower strength product to see how your skin will react and to give it the time to adjust to GA. However, if you feel that it is very irritating for your skin, even in the lowest concentration, don’t use it. Try with another gentler alpha-hydroxy acid, Mandelic acid for example  or you can try the use of PHAs. You don’t need to follow the trends. It is essential to protect your skin barrier.

Don’t introduce to your skincare more active ingredients at the same time. Give your skin the time to adjust to the new substance.

To be effective glycolic acid must be at a pH 3-4 and concentrations 5-10%.

To sum up, the use of GA may be beneficial if used correctly. However, don’t try to incorporate the GA in your skincare routine if your skin doesn’t tolerate it. There are other options as well. Your main concern should always be protecting your skin barrier.