extrapolating across different parts of a botanical (i.e., roots, stems, flowers, and leaves) in the safety assessment? A safety review should attempt to explain different dietary supplement ingredient preparations and how those different preparations might change the safety assessment. For some ingredients that are well characterized this is not an issue, but for many botanical ingredients it is important to understand the plant part used, as well as the effect of different methods of preparation that may concentrate active compounds or otherwise alter the activity of the ingredient.
Does the review focus on the safety of a particular standardized product? Frequently, reviews from another country describe the safety of standardized preparations of supplements available in that country; however, the relevance of such reviews to the safety of nonstandardized products consumed in the United States should be addressed for such reviews to be considered relevant to U.S. consumers. Reviews describing the safety of a standardized product are helpful in understanding some safety concerns inherent in the ingredient, but less relevant to safety concerns that vary with preparation. Similarly, good reviews will convey limitations inherent in extrapolating from studies suggesting safety of one standardized product to other products of the same ingredient. That is, they acknowledge that extrapolation to other products to mitigate safety concerns may be inappropriate.
Is the ingested amount (or range of ingested amounts) under consideration specified in the review? Does the review address the relevance of the amount used in the evaluated research studies and published data to the amount commonly ingested or recommended for ingestion? Given the basic tenet of toxicology, “the dose makes the poison,” a good review of safety will describe the relevance of ingredient levels that produce safety concerns to the ingredient levels commonly consumed by or recommended to humans. (Many resources available to consumers specify recommendations for consumption, even if the labeling per se does not include recommended ingestion levels.)
Does the review consider the relevance of data that describes results of non-oral administration of the ingredient? While safety issues with oral consumption are obviously the most relevant, some safety issues that come to light with other routes of administration may also be relevant. The relevance of such issues should be considered on a case-by-case basis, but expressly disregarding any safety information derived from non-oral exposure is not appropriate for some dietary supplement ingredients, especially when sufficient, quality data about oral ingestion are lacking. A review that considers non-oral data in its evaluation will have more value to FDA than one that ignores this type of information regardless of relevance. In many of the resources described, it was not evident whether non-oral data were considered.