Summary

In this episode of the Root Cause Medicine Podcast, Dr. Kate Kresge is joined by Dr. Eric Viegas, a leader in supplement safety at Fullscript, for a timely and evidence-informed discussion on lead exposure in protein powders and nutritional supplements. Amid rising media attention and consumer concern, the conversation unpacks how and why trace amounts of lead can appear in supplements, how different regulatory thresholds (Prop 65 vs. USP/ICH) should be interpreted clinically, and what toxicologically relevant exposure actually means. Clinicians will gain practical insight into cumulative lead exposure, patient risk stratification, and how Fullscript is advancing supplement quality through enhanced testing, transparency, and practitioner-facing safeguards.


Clinical Takeaways from This Episode

• Lead Detection vs. Clinical Risk Assessment in Supplements
  • Dr. Eric explains that detecting trace lead does not automatically equate to clinical harm; modern analytical testing is extremely sensitive, and risk must be contextualized using toxicology-based thresholds and cumulative exposure.
• Understanding Prop 65 vs. USP/ICH Lead Thresholds
  • California Prop 65 applies large safety buffers designed to trigger warnings, while USP 232 and ICH Q3D limits are toxicologically derived and commonly used in pharmaceutical-grade quality systems.
• Cumulative Lead Exposure and Patient-Specific Risk Factors
  • Total exposure from diet, water, environment, and supplements—especially in pregnancy, pediatrics, kidney disease, or high environmental burden—should guide clinical decision-making (FDA, 2025).
• Why Plant-Based Protein Powders Are More Vulnerable
  • Ingredients such as rice, peas, and hemp may bioaccumulate heavy metals from soil and water, and processing can further concentrate these compounds (Hasan, 2022).
• Beyond Heavy Metals: Broader Protein Powder Quality Metrics
  • Clinicians should also consider microbes, pesticides, residual solvents, phytates, and banned substances when evaluating protein powders.
• Clinical Value of Certificates of Analysis (COAs)
  • Batch-specific COAs provide greater transparency than general certifications and allow clinicians to verify contaminant screening for the exact product lot (CHPA, 2010).
• Role of Enhanced Finished-Product Testing in Integrative Care
  • Platforms like Fullscript are supporting clinicians by conducting independent, third-party testing and surfacing results directly within the clinical workflow.
    
    

Timestamps

00:00 Welcome and episode overview
01:48 Why lead in protein powders is trending now
03:58 Detectable does not always mean dangerous
04:30 How to interpret lead amounts and cumulative exposure
05:58 Other supplement contaminants to consider
07:45 Why plant-based proteins carry higher risk of heavy metal uptake
10:55 What certifications to look for and why they matter
13:10 What Fullscript is doing, enhanced testing, and safeguards
15:10 How to assess lead exposure in clinical practice18:11 What Dr. Viegas wants to change in the supplement industry20:02 How to choose a safer protein powder21:59 Final takeaways and closing


Guest Introduction


Eric Viegas, ND
Dr. Eric Viegas is a leader in supplement safety and quality assurance at Fullscript, where he oversees contaminant screening, regulatory alignment, and enhanced testing initiatives across multiple supplement categories. His work focuses on bridging pharmaceutical-grade toxicology standards with real-world clinical practice to support practitioner confidence and patient safety. Fullscript Quality & Education: https://fullscript.com


Labs, Nutrition, and Lifestyle Support


Lead Exposure Assessment and Monitoring

• Blood lead testing for evaluating current exposure (CDC, 2024)
• Environmental assessment of drinking water and occupational or environmental exposure (PEHSU, 2025)

Protein Powder Selection and Nutrient Quality Considerations

• Preference for brands with third-party cGMP certifications
• Review of batch-specific Certificates of Analysis (COAs) (CHPA, 2010)
• Awareness that organic certification does not eliminate heavy metal risk (Ramakrishnan, 2021)

Citations

• Clean Label Project. Heavy Metals in Protein Powders. Retrieved October 2025 from https://cleanlabelproject.org/protein-study-2-0/ 
• Consumer Reports. Protein Powders and Lead Levels. October 2025. https://www.consumerreports.org/lead/protein-powders-and-shakes-contain-high-levels-of-lead-a4206364640/ 
• United States Food and Drug Administration. FDA Draft Guidance on Lead in Food Intended for Babies, Children, and Adults. Updated January 2025. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-action-levels-lead-processed-food-intended-babies-and-young-children 
• EFSA. EFSA scientific report on dietary exposure to lead in the European population. June 30, 2025. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2025.9577 
• World Health Organization. Lead Poisoning and Health. September 2024. https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health 
• Centers for Disease Control. CDC Updates Blood Lead Reference Values. April 2024. https://www.cdc.gov/lead-prevention/php/news-features/updates-blood-lead-reference-value.html
• US Pharmacopeia. USP 232 Elemental Impurities - Limits. https://www.usp.org/sites/default/files/usp/document/our-work/chemical-medicines/key-issues/c232-usp-39.pdf 
• International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Harmonised Guideline: Guideline for Elemental Impurities Q3D(R2). 26 Apr. 2022. https://database.ich.org/sites/default/files/Q3D-R2_Guideline_Step4_2022_0308.pdf 
• Consumer Healthcare Products Association. Certificate of Analysis for Dietary Supplement Components. Consumer Healthcare Products Association. Apr. 2010, www.chpa.org/public-policy-regulatory/voluntary-codes-guidelines/certificate-analysis-dietary-supplement 
• Hasan, G. M. M. Anwarul, et al. “Accumulation of Heavy Metals in Rice (Oryza Sativa. L) Grains Cultivated in Three Major Industrial Areas of Bangladesh.” Journal of Environmental and Public Health, vol. 2022, 8 Mar. 2022, p. e1836597, https://doi.org/10.1155/2022/1836597 
• “Chemical Exposure Warnings (Proposition 65 Warnings).” Ca.gov, 2021, www.p65warnings.ca.gov/ 
• Ramakrishnan, Balasubramanian, et al. “Organic Farming: Does It Contribute to Contaminant-Free Produce and Ensure Food Safety?” Science of the Total Environment, vol. 769, 15 May 2021, www.sciencedirect.com/science/article/abs/pii/S0048969721001455 
• “Lead Exposure: Information for Health Professionals.” PEHSU - Pediatric Environmental Health Specialty Units, 7 Nov. 2025, pehsu.net/health-issue/lead-hcp/ Accessed 31 Dec. 2025.

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.