Sodium Metabisulfite

Science & Benefits

Sodium Metabisulfite is an inorganic salt that functions as both a preservative and a powerful antioxidant. It is frequently used to prevent the discoloration (browning) of sensitive actives like Vitamin C or Hydroquinone. Despite its zero comedogenic rating, it is a significant 'Red Flag' for irritancy. It can trigger allergic reactions and skin flushing in a subset of the population. For users with a history of rosacea or hyper-reactive skin, this ingredient can cause micro-inflammation that mimics a breakout. It is a necessary functional ingredient for formula stability but a potential trigger for barrier-compromised users.