This formula's own materials cite the NCCIH's "Herbs at a Glance" resource specifically — worth checking directly what this particular source actually covers.
NCCIH's Herbs at a Glance is a series of botanical supplement overviews published by the National Center for Complementary and Integrative Health, a real, checkable government resource distinct from the NIH and PubMed sources also cited.
This formula's own materials name NIH, NCCIH, and PubMed as three separate references rather than one vague citation — worth checking each individually, while remembering this formula's own materials state it is not affiliated with or endorsed by any of them.