Paraxanthine from Mexico
Paraxanthine, a caffeine metabolite, features dimethylxanthine structure with nitrogen hetero-atoms in fused rings, aromatic per 2933.99. Falls under U.S. note 3 products. Applied in sports nutrition and metabolic research.
Duty Rate — Mexico → 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
9903.05.5510%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
• Provide stability data showing no degradation products above 0.1%
• Declare CAS number 611-59-6 on commercial invoice for CBP verification
• Avoid retail packaging to prevent reclassification under chapter 33 or 30