Aminoethanesulfinic Acid

Aminoethanesulfinic acid is a small-molecule antioxidant compound with reducing properties. It belongs to a class of ingredients designed to neutralise free radicals and reactive oxygen species that accumulate on the skin through environmental exposure and natural metabolic processes.

This ingredient functions by donating electrons to unstable molecules, effectively stabilising them before they can damage skin cells. It is typically used in skincare formulations to provide antioxidant defence, often working alongside other protective ingredients to support skin resilience.

Aminoethanesulfinic acid works through a reducing mechanism, meaning it donates electrons to oxidised molecules and converts them into stable, harmless compounds. This process interrupts the chain reaction of free radical damage that can lead to premature skin ageing and inflammation.

Because of its reducing properties, this ingredient can also help maintain the stability and efficacy of other antioxidants and actives within a formula, preventing them from degrading.

This ingredient is most effective as part of a comprehensive antioxidant routine. Apply it as directed by your product instructions, typically in the morning or evening after cleansing. It pairs well with sunscreen during the day to reinforce environmental protection, and can be layered with other antioxidants such as vitamin C or niacinamide for cumulative benefit.