Theanine

Available as a dietary supplement.⁶ Freely available to possess and distribute without restriction.

Across the United Kingdom, L-theanine (theanine; CAS 3081-61-6), the (2S) stereoisomer identified as PubChem CID 439378, is absent from the Home Office controlled-drugs list, the revised Schedule 2 to the Misuse of Drugs Act 1971, and the revised Schedules 1–5 to the Misuse of Drugs Regulations 2001. No UK controlled-drug class, schedule, designation, penalty or analogue provision is specified for this amino-acid identity. For controlled-substance purposes, L-theanine is legal, but its availability remains subject to product-regulatory conditions. MHRA says familiar amino-acid food supplements are generally food-regulated unless presented for medicinal use, while FSA says food supplements are not medicinal products and may not be marketed as treating, preventing or curing disease. Theanine has no identified FSA novel-food authorisation, but this does not establish whether it is novel; isolated or manufactured form, source, process, dose and intended use may matter. The GB NHC register rule is specific to Great Britain. Northern Ireland food-law status and any product-specific authorisation, labelling, claims, import or retailer requirements depend on the product. The legality of commercial formulations and listings likewise depends on their particular characteristics.