Valerian is a botanical preparation containing a characteristic profile of plant secondary metabolites—alkaloids, flavonoids, terpenoids, phenolic acids, and glycosides—whose combined pharmacological activity determines its therapeutic utility. Chemical variability inherent to botanical materials requires standardisation to defined marker compound concentrations and drug-to-extract ratios to ensure consistent biological activity across batches. Toxicological evaluation of Valerian encompasses the full chemical complexity of the preparation, including assessment of individual toxic constituents and any contaminants such as pesticide residues, heavy metals, or mycotoxins.
The severe toxicity modifier F4 in PDE derivation for Valerian is applied when the nature of the critical adverse effect warrants additional conservatism beyond the default interspecies and intraspecies uncertainty factors.