From moisture-zapping winds to heavy-knit hats that tug on your already-dry strands, there's no denying winter's impact on our hair. On our quest to unlock a more nourished, healthier mane, we came across a crowd-loved serum that shoppers consider a "luxe wellness retreat for your hair." Powered by a trio of nourishing ingredients, the CosmoCap Daily Hair Serum delivers a spa-like experience with each use. The formula is enriched with silk protein, which boosts elasticity and delivers the sleek, glass-like shine we love.