The Ordinary Amino Acids + B5 The Ordinary Amino Acids + B5 ($7) features 17 percent amino acids (and amino acid derivatives) to strengthen skin's barrier function, elasticity, and overall balance. The popular serum (with a 4.6-star rating from other Sephora shoppers) also includes five percent vitamin B5 to help skin repair itself and stay hydrated, too. Image Source: sephora.com Amino Acids + B5 $7 from sephora.com Buy Now