DL-Tryptophan from Canada
DL-Tryptophan, an indole-containing aromatic amino acid with single oxygen function, is specified in additional U.S. note 3 to section VI, fitting HTS 2922.49.30.00. It is essential for serotonin synthesis in supplements.
Duty Rate — Canada → United States
110%
Rate breakdown
9903.04.6093.5%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
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• Include COA confirming no impurities exceeding chapter limits; subject to FDA import alerts for purity
• Pitfall: classifying racemic form as separate from L-form