Tryptophan from Mexico
L-Tryptophan is an essential amino acid featuring an indole side chain attached to alanine, classified under HTS 2933.99.0500 due to its indole structure. The heterocyclic nitrogen compound takes precedence over amino acid classification.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.60100%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Indole amino acids classified here, not with other amino acids, per heterocyclic precedence
• Pharma grade requires USP certificate; feed grade may have different documentation
• Avoid Chapter 29 note 3(C) salt classification issues with pure free acid form