Topical Collagen: What Are the Dangers, Side Effects, and Contraindications?

Found in masks, creams, and serums, collagen is primarily used in cosmetics to hydrate the skin. Indeed, this molecule, naturally present in the connective tissue of the dermis, has the ability to form an occlusive film that retains water and prevents its evaporation. In doing so, it protects the skin from dehydration and certain external aggressions. Studies have also shown that collagen possesses antioxidant and restructuring properties, making it a good active ingredient for preventing skin aging.

Although its concentration in cosmetic products is not subject to a limit, collagen is generally incorporated at a level of 1 to 2%, as a higher amount does not provide additional benefits and can weigh down the texture of the skincare products.

Due to its high biocompatibility, collagen is a cosmetic active ingredient that is generally very well tolerated.

Nevertheless, even though this active ingredient generally does not cause side effects, zero risk does not exist and some individuals are allergic to collagen. Scientists have reported cases of two individuals who, after applying bovine collagen around the eye area, experienced significant redness and swelling in that region. However, this reaction subsided within a few hours after rinsing off the collagen. Researchers explain this by the presence of specific antibodies (IgE) to collagen in some individuals. Therefore, as a precautionary measure, it is advised that people allergic to shellfish or fish avoid applying marine collagen to their skin.

A more eco-friendly and safer alternative, plant-based collagen is increasingly favored. This form of collagen, derived from biotechnological processes, is also popular in nutricosmetics, where it helps mitigate the health risks associated with the oral intake of animal collagen, such as bovine spongiform encephalopathy, avian influenza , and foot-and-mouth disease. Nevertheless, while the risk of skin reactions is reduced when using plant-based collagen, it is still advisable to perform a tolerance test before using a new cosmetic. If an adverse effect appears after application in the crook of the elbow, on the inner wrist, or behind the ear, it is recommended to discontinue use of the product.