When Labels Lie: The St. John’s Wort Report
A recent analysis of 22 St. John’s Wort supplements purchased online found that only one actually matched its label for the key compound hypericin. Several products contained little to none of the active ingredient, and some appeared to use synthetic dyes to mimic the color of hypericin, potentially misleading simple testing methods (Now, 2025). 


Why does this matter? Because when a supplement doesn’t contain the ingredient it claims, patients may not receive the support they expect. That can lead to wasted money, confusing clinical outcomes, and lost trust in integrative care. In this episode of the Root Cause Medicine Podcast, we’re joined by Dr. Eric Viegas, Medical Product Manager at Fullscript, to unpack what this report means for clinicians and patients. We discuss how ingredient discrepancies can happen—from plant sourcing and manufacturing to risks in online marketplaces—and how practitioners can help protect patients from misleading products. We also explore what clinicians should look for when choosing supplements, including validated testing methods, Certificates of Analysis, and quality standards that help ensure products contain what the label promises.

Clinical Takeaways from This Episode

• Supplement quality directly affects clinical decision-making
  If a product does not contain the labeled ingredient or dose, clinicians may struggle to determine whether a therapy is supporting patient outcomes.
• Botanical supplements can vary widely in active compounds
  Factors such as plant sourcing, harvest timing, and extraction methods may influence the concentration of active constituents like hypericin (Butterweck, 2007).
• Quality verification systems help reduce risk
  Third-party cGMP certification, validated laboratory testing, and transparent supply chains may help clinicians identify supplements with stronger quality controls (FDA, 2024).
  
  

Guest Introduction


Dr. Eric Viegas is a Medical Product Manager at Fullscript specializing in supplement quality assurance and ingredient verification. His work focuses on evaluating nutraceutical ingredients, reviewing manufacturing standards, and supporting clinicians who use professional-grade supplements as part of integrative care.

Labs, Nutrition, and Lifestyle Support


Understanding St. John’s Wort standardization

• Extracts are commonly standardized to 0.3% hypericin, a marker used to estimate potency.
  
  

Supplement quality indicators clinicians may review

• Certificates of Analysis (COAs) verifying ingredient identity and potency
• Third-party cGMP certification for manufacturing facilities
• Testing for contaminants such as heavy metals, pesticides, microbes, and solvents
  
  

Analytical methods used to confirm botanical ingredients

• High-performance liquid chromatography (HPLC)
• High-performance thin-layer chromatography (HPTLC)
  
  

These analytical techniques help verify the presence and concentration of botanical compounds.

Key Moments


00:00 — When supplement labels don’t match what’s inside the bottle
Why ingredient accuracy matters for patient care.


02:23 — The St. John’s Wort investigation explained
A breakdown of the analysis showing that only one product matched its hypericin label claim (NOW, 2025).


05:20 — Why missing active ingredients affect outcomes
How inaccurate potency may influence patient expectations and treatment evaluation.


07:10 — Why botanicals are especially vulnerable to variability
How growing conditions, plant parts, and extraction methods influence active compounds (Butterweck, 2007).


10:54 — How quality verification works behind the scenes
What manufacturers and distributors may do to verify supplement quality.


16:01 — Why this issue extends beyond St. John’s Wort
Other botanicals may also vary in potency depending on sourcing and manufacturing.

Disclaimer


The views expressed on this podcast are those of the hosts and guests and don’t necessarily reflect those of Fullscript or any affiliated organizations. This podcast is for informational and educational purposes only and is not intended to be medical advice. For your safety, always check with your doctor or healthcare provider before making changes to your health routine.

Citations

1. Butterweck V, Schmidt M. St. John's wort: role of active compounds for its mechanism of action and efficacy. Wien Med Wochenschr. 2007;157(13-14):356-61. doi: 10.1007/s10354-007-0440-8. PMID: 17704987.
2. Barnes J, Anderson LA, Phillipson JD. St John's wort (Hypericum perforatum L.): a review of its chemistry, pharmacology and clinical properties. J Pharm Pharmacol. 2001 May;53(5):583-600. doi: 10.1211/0022357011775910. PMID: 11370698. 
3. Izzo AA. Interactions between herbs and conventional drugs: overview of the clinical data. Med Princ Pract. 2012;21(5):404-28. doi: 10.1159/000334488. Epub 2012 Jan 11. PMID: 22236736.
4. NOW Tests St. John’s Wort Supplements Sold on Amazon. NOWFoods.com October 29, 2025. https://www.nowfoods.com/healthy-living/articles/now-tests-st-johns-wort-supplements-sold-amazon
5. USFDA. Current Good Manufacturing Practices (CGMPs) for Food and Dietary Supplements. Published 04/24/2024. https://www.fda.gov/food/guidance-regulation-food-and-dietary-supplements/current-good-manufacturing-practices-cgmps-food-and-dietary-supplements