Mutant Amino 300 Tablets is a comprehensive essential amino acid supplement that contains all 9 essential amino acids, including the 3 branched-chain amino acids (BCAAs), as well as arginine. Some key features of this product: Provides 9.4g of EAAs and 7g of BCAAs per serving to support muscle growth and recovery Made from vegan, fermented amino acids with no artificial colors or flavors Helps reduce delayed onset muscle soreness Independently lab tested for banned substances Available in 300 tablet bottles The TSB acronym likely refers to the product being sold through retailers like The Supplement Box (TSB). Reviews indicate Mutant Amino 300 Tablets has an excellent taste, mixes well, and is an effective essential amino acid supplement.