Phytosterols: What are the dangers of their use in cosmetics?

Phytosterols are compounds naturally found in plants. They belong to the sterol family and have a similar structure and role to the cholesterol present in the human body. Phytosterols are primarily known for their health benefits, particularly for cardiovascular health. However, they also have benefits when applied topically to the skin and hair, and are included in the formulation of many cosmetic products. Phytosterols are especially known for their soothing and repairing virtues, making them allies for sensitive skin. These compounds are also good humectant agents.

Furthermore, phytosterols possess antioxidant properties. These properties stem from their cyclic chemical structure, which allows them to stabilize free radicals by donating an electron before they can damage DNA and cellular constituents. Lastly, a recent study has shown that phytosterols can delay skin aging. They work by inhibiting collagenase, the enzyme that breaks down the peptide bonds of collagen. The loss of structure of this compound results in a loss of function and a decrease in skin elasticity.

Phytosterols are compounds considered to be safe and non-irritating and their concentration in cosmetic products is not subject to restriction by European cosmetic regulations. This is based on Regulation (EC) No 1223/2009 which defines the requirements that cosmetic products must meet. These include safety, labeling, product composition, good manufacturing practices, as well as product notification and the obligations of manufacturers and distributors.

Although they are not subject to a concentration limit, phytosterols are generally not incorporated at more than 5% in cosmetic care, as this does not provide additional benefits. Moreover, these plant compounds are not part of the cosmetic actives advised against during a pregnancy or breastfeeding. They are also suitable for children from 3 years old.

Note : we are only discussing here the topical use of phytosterols. The oral intake of phytosterol-based medications is regulated and, if you need to resort to it, it is necessary to strictly follow your doctor's recommendations.

• CABRAL J. & al. Phytosterols: applications and recovery methods. Bioresource technology (2007).

• BECKER L. Safety Assessment of Phytosterols as Used in Cosmetics. Cosmetic ingredient review (2013).