FDA Finalises NDI Guidance on Identity and Safety Documentation

The US Food and Drug Administration (FDA) has published finalised guidance detailing the identity specifications and safety documentation required when submitting a New Dietary Ingredient (NDI) notification. The document resolves key sections of the agency's draft guidance originally published in 2016, providing dietary supplement manufacturers, raw material suppliers, and brand owners with defined benchmarks for market pre-notification under Section 413 of the Federal Food, Drug, and Cosmetic Act (FD&C Act). Under US law, an NDI notification must be submitted to the regulator at least 75 days prior to introducing a dietary supplement containing an NDI into interstate commerce, unless the ingredient has been present in the food supply as an article used for food in a form in which the food has not been chemically altered. ### Requirements for Chemical and Physical Characterisation The finalised guidance places rigorous emphasis on the physical and chemical characterisation of novel ingredients. The FDA stipulates that notifications must present comparative analytical data demonstrating equivalence between the specific material evaluated in safety studies and the commercial-grade ingredient intended for finished goods. Key parameters outlined in the guidance include: * **Identity testing specifications:** Comprehensive specifications covering physical properties, chemical composition, assay parameters, and impurity profiles (including residual solvents, heavy metals, pesticides, and microbiological limits). * **Manufacturing process details:** Complete narrative flowcharts detailing raw material inputs, extraction solvents, processing aids, reaction parameters, and batch-to-batch reproducibility across at least three non-consecutive commercial-scale batches. * **Botanical characterisation:** For botanical extracts, confirmed taxonomic identification (genus, species, subspecies, author, and plant part utilised), geographic origin, and quantitative marker profiles for active or characteristic constituents. ### Substantiating Safety: Testing Frameworks and Historical Exposure To substantiate that an NDI is reasonably expected to be safe under its proposed conditions of use, submitters must compile toxicological dossiers tailored to the nature and anticipated exposure level of the substance. The guidance delineates distinct standards for ingredients with historical dietary exposure versus novel or chemically altered entities. Where historical food consumption data are cited, the FDA specifies that documentation must confirm real-world intake at levels, durations, and in populations directly comparable to the proposed supplement use. General folklore references, anecdotal records, and broad traditional use remain insufficient to substantiate safety. For substances lacking documented dietary exposure records, the agency confirms the requirement for structured toxicological evaluations. Depending on exposure duration and chemical structure, dossiers may require: * *In vitro* and *in vivo* genetic toxicity test batteries. * Repeated-dose 14-day or 28-day oral toxicity studies. * Subchronic 90-day oral toxicity studies in rodent models. * Teratogenicity and reproductive toxicity evaluations where indicated by intended target populations or exposure profiles. ### Implications for Global Manufacturers and Exporters For UK and European manufacturers exporting finished dietary supplements or novel raw materials to the United States, the guidance reinforces the necessity of compiling robust technical dossiers ahead of commercial distribution. While the US NDI notification framework is distinct from the European Union Novel Food regime (Regulation (EU) 2015/2283) and the parallel UK regime administered by the Food Standards Agency (FSA), convergence in analytical expectations means analytical packages compiled for European dossiers may partially support NDI submissions, provided FDA-specific exposure calculations and identity thresholds are met. The agency noted that adherence to these structured parameters is intended to reduce the rate of deficiency notices, requests for additional data, and objection letters issued due to incomplete identity specifications or insufficient safety packages.