The effects of chlormequat chloride, a typical plant growth regulator, on the medicinal herb Corydalis yanhusuo were investigated. A standardized field experiment was conducted to investigate the molecular mechanisms and variations in active compounds resulting from chlormequat chloride treatment. Samples of C. yanhusuo were collected under controlled conditions and at varying doses of chlormequat chloride. The differential compounds identified in both control and treated groups of C. yanhusuo were primarily alkaloids, as determined by non-targeted metabolomics analysis. The metabolite content was determined through the precise quantification of 12 enriched alkaloidal compounds across various categories of C. yanhusuo using targeted metabolomics. A comprehensive metabolomics evaluation method was developed that focuses on pharmacodynamically active compounds. Transcriptomic analysis also facilitates the identification of differential genes and enzymes associated with alkaloid production between the two groups. Chlormequat chloride significantly increased the yield of C. yanhusuo, but the content of the quantitatively abundant alkaloids decreased. It was suggested that the level of cytochrome P450 enzymes, primarily involved in the biosynthesis of benzylisoquinoline alkaloids, was inhibited by chlormequat chloride. In conclusion, this study revealed a dose-dependent effect of chlormequat chloride on C. yanhusuo and its associated molecular mechanisms as determined by omics analysis.Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.