FD&C Yellow No. 5
Synthetic azo dye (tartrazine) — yellow food colouring. Most studied of FD&C dyes due to well-documented hypersensitivity reactions. Associated with urticaria, asthma exacerbation, and hyperactivity in children. Cross-reacts with aspirin in salicylate-sensitive individuals. EU mandatory disclosure required.
How it works (mechanism of action)
Acts on cellular signalling pathways relevant to the documented clinical indications. Contains bioactive compounds with enzyme-modulating, receptor-binding, or antioxidant properties studied in peer-reviewed literature.
EU mandatory warning: "May have an adverse effect on activity and attention in children." FDA requires specific label declaration. Cross-reacts with aspirin in 10-40% of aspirin-sensitive individuals causing urticaria/asthma. Avoid in asthma, urticaria, aspirin sensitivity, ADHD. Norway banned tartrazine (later lifted with EU harmonisation). Significant hyperactivity concern in children.