Stratum Corneum is a compacted layer of corneocytes embedded in a lipid matrix, that forms a semipermeable barrier on the surface of the skin. Despite its seemingly delicate thinness of 10-30 μm, the Stratum Corneum [SC] plays a vital role in serving as a first line of defense to protect against external environmental stressors. Even minor disruption to this layer can lead to a loss of barrier integrity that manifest as an increase in Transepidermal Water Loss [TEWL]. Many common cosmetic dermatological treatments can inflict varying degrees of short-term damage to the SC. In order to help the SC maintain and restore barrier function, a topical serum was developed containing a combination of Macrocystis pyrifera ferment and other ingredients. This preparation is shown in clinical studies to strengthen the barrier of intact skin, making the barrier not only more robust against mild skin disruption but also to enhance barrier recovery even after the intense effects of cosmetic dermatological treatments such as peels and laser treatment. Moreover, this barrier repair serum is shown to be more effective at helping the barrier recover than a conventional moisturizing lotion during post-treatment recovery. Through a series of in vivo evaluations, this serum is shown to reduce TEWL of intact skin, to help build back SC quality, to reduce the immediate barrier disruption caused by cosmetic glycolic peel or laser procedures and to help SC barrier recovery post-procedure. To build upon the in vivo findings, immunohistochemical analysis of ex vivo skin demonstrated that 70 % glycolic acid acutely disrupts the tight junction protein, claudin-1 and filaggrin. Ex vivo skin pretreated with the serum exhibited intact claudin-1 morphology and showed a greater signal intensity of both claudin-1 and filaggrin compared to ex vivo skin treated with glycolic acid alone, suggesting that the serum may contribute to accelerated barrier recovery.