Fibronectin is a large protein naturally found in the blood and in the supportive tissue that surrounds skin cells, where it plays a key role in helping cells stick together, move, and heal after an injury. It works like a kind of scaffolding, latching onto both cells and the surrounding tissue to guide new skin cells into damaged areas as they repair.
In wound healing studies, fibronectin applied to a wound has measurably sped up the skin's ability to grow back over damaged areas, even in harder to heal skin, such as skin that has been through radiation treatment. That said, this evidence comes from actual wounds treated with much higher, often medically administered doses, not from studies testing fibronectin as an everyday leave on cosmetic on healthy, intact skin.
Our team reviews ingredient research and uses up-to-date evidence to rate ingredients based on the categories below.
Best
Ingredients with the most rigorous and convincing evidence. These are the standouts backed by consistent findings across independent, peer reviewed clinical research.. When we call an ingredient Best, it has earned that distinction through genuine, reproducible proof that it improves skin.
Good
Reliable, well tolerated ingredients that do their job without complaint. They may not carry the headline benefits of a Best rated active, but they hydrate, stabilize a formula, or support the ingredients around them in ways that make a real difference in how a product performs and feels.
Average
Ingredients that are perfectly safe and serve a clear function, typically as an emollient, thickener, or filler, but do not offer any meaningful skin benefit beyond that basic job. Not a red flag, just not a reason to choose one product over another.
Bad/Worst
Ingredients with documented potential to irritate skin, disrupt the barrier, or trigger sensitization in some users, often synthetic fragrance, drying forms of alcohol, or certain essential oils. Not automatically a dealbreaker for every skin type, but worth knowing about before you commit to a product.
