DL-Tryptophan from Japan
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 — Japan → United States
21%
Rate breakdown
9903.04.628.5%Patented pharmaceutical articles that are the product of Japan, of a European Union member country, of South Korea, of Switzerland, or of Liechtenstein as provided for in subdivisions (c) and (f) of U.S. note 40 to this subchapter
9903.05.4912.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of Japan, with an ad valorem (or ad valorem equivalent) rate of duty under column 1 less than 12.5 percent, 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