# Goldenseal (Hydrastis canadensis) *Golden seal, yellow root, orange root, yellow puccoon, ground raspberry, wild curcuma, turmeric root, Indian dye, eye root, eye balm, Indian paint, jaundice root, Warnera; *Hydrastis canadensis* L.* **Known today as.** *Hydrastis canadensis*, a small perennial herb of the buttercup family, Ranunculaceae, native to Canada and the eastern United States, growing in rich soil in shady woods. Its knotted rhizome is bright yellow; its fruit, a head of small crimson berries, has much the appearance of a raspberry, “whence the name ‘Ground Raspberry,’” Grieve notes, but is not edible. The rhizome is the drug. Grieve gives its chief constituents as the alkaloids berberine, the yellow colouring matter, and hydrastine, with a third, canadine. Kind: Plant > **Caution.** Grieve warned that “in large amounts the drug proves very poisonous.” The 2020 review notes that a few studies have suggested possible neurotoxic, hepatotoxic, and phototoxic activity of the extract and its alkaloids. LiverTox has no chapter on goldenseal itself; its chapter on berberine, one of its alkaloids, finds that berberine has not been linked to clinically apparent liver injury. It can alter the levels of other medicines, as above. ## What was it used for? A bitter tonic for the digestion and a remedy for catarrh. Grieve records that the American aborigines valued the root highly “as a tonic, stomachic and application for sore eyes and general ulceration,” and that in her day it was employed in dyspepsia, gastric catarrh, loss of appetite, and liver troubles, as a snuff for nasal catarrh, and as a lotion for the eyes. A 2020 review lists its traditional Native American uses as a colouring agent and for wounds, digestive disorders, ulcers, skin and eye ailments, and cancer, and notes that it has become a popular food supplement in the United States. ## What does modern science say? No European monograph covers it. The 2020 review reports that goldenseal extract containing berberine has shown antimicrobial, anti-inflammatory, and other effects in research, but concludes that large randomised, double-blind clinical studies of goldenseal supplements are still needed to establish their efficacy and safety. Its clearest effects in people are on other medicines. In healthy adults it raised blood levels of midazolam, a drug broken down by the enzyme CYP3A, by 40 to 60 per cent, chiefly, a 2023 study concluded, through the alkaloid -hydrastine acting in the gut. In a 2025 crossover trial in adults with type 2 diabetes it caused no clinically meaningful change in metformin levels overall, though at low metformin doses exposure fell by about a fifth; the authors suggest that prescribers may caution patients against combining the two. ## Pharmacognosy and toxicology - **berberine**: the yellow colouring matter, 3.5 to 4 per cent by Grieve’s figures - **hydrastine**: 2 to 4 per cent; the alkaloid Grieve credited with its virtues - **canadine**: a third alkaloid **Mechanism.** Goldenseal inhibits the enzyme CYP3A in the gut, chiefly through the alkaloid -hydrastine, a 2023 study concluded, raising blood levels of midazolam by 40 to 60 per cent in healthy adults. **Standing.** There is no European monograph. A 2020 review calls for large randomised, double-blind trials of goldenseal supplements. ## What lore surrounds it? Grieve held that the plant “owes its virtues almost entirely to Hydrastine,” the berberine, apart from some effect as a bitter, being practically inert. Modern work has turned the emphasis round: the 2020 review calls berberine one of the most bioactive of its alkaloids. ## What did the older authorities say? **Grieve, *A Modern Herbal* (1931).** Miller first brought it into England in 1760 under the name of *Warnera*, after Richard Warner of Woodford. A United States Department of Agriculture bulletin of 1905 recorded that the early settlers learnt of its virtues from the American Indians, who used the root as a medicine and its yellow juice as a stain for their faces and a dye for their clothing; it became an article of commerce only about 1850, and overcollection and the felling of the forests of the central States made it scarce and its price, by Grieve’s account, “almost prohibitive.” ## Sources - Grieve, M. *A Modern Herbal*, “Golden Seal.” As published on botanical.com. - Mandal SK, et al. (2020). Goldenseal (Hydrastis canadensis L.) and its active constituents: A critical review of their efficacy and toxicological issues. *Pharmacological research*. PMID 32683037. - Nguyen JT, et al. (2023). An Integrative Approach to Elucidate Mechanisms Underlying the Pharmacokinetic Goldenseal-Midazolam Interaction: Application of In Vitro Assays and Physiologically Based Pharmacokinetic Models to Understand Clinical Observations. *The Journal of pharmacology and experimental therapeutics*. PMID 37541764. - Nguyen JT, et al. (2025). The Pharmacokinetic Interaction Between Metformin and the Natural Product Goldenseal Is Metformin Dose-Dependent: A Three-Arm Crossover Study in Adults With Type 2 Diabetes. *Clinical and translational science*. PMID 39943692. - LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, “Berberine.” National Institute of Diabetes and Digestive and Kidney Diseases, updated 2020. NCBI Bookshelf. - Grieve, M. *A Modern Herbal*, “Golden Seal.” As published on botanical.com. - Mandal SK, et al. (2020). Goldenseal (Hydrastis canadensis L.) and its active constituents: A critical review of their efficacy and toxicological issues. *Pharmacological research*. PMID 32683037. - Nguyen JT, et al. (2023). An Integrative Approach to Elucidate Mechanisms Underlying the Pharmacokinetic Goldenseal-Midazolam Interaction: Application of In Vitro Assays and Physiologically Based Pharmacokinetic Models to Understand Clinical Observations. *The Journal of pharmacology and experimental therapeutics*. PMID 37541764. - Nguyen JT, et al. (2025). The Pharmacokinetic Interaction Between Metformin and the Natural Product Goldenseal Is Metformin Dose-Dependent: A Three-Arm Crossover Study in Adults With Type 2 Diabetes. *Clinical and translational science*. PMID 39943692. - LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, “Berberine.” National Institute of Diabetes and Digestive and Kidney Diseases, updated 2020. NCBI Bookshelf. --- *Goldenseal.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-17. The Thinking Press. https://thethinkingpress.org/materia-medica/goldenseal Historical description, not medical advice.