DL-Tryptophan from Mexico
DL-Tryptophan racemic mixture used as sleep aid precursor and animal feed supplement post-1989 EMS outbreak clearance. HTS 2922.49.49 for other amino acids despite indole ring. Regulated for human consumption purity.
Duty Rate — Mexico → United States
14.2%
Rate breakdown
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
• ,Separate human vs animal grade shipments; different FDA oversight
• Declare serotonin pathway warnings for supplement labeling compliance