Lead in Protein Powders: The Truth from Dr. Eric Viegas

In this episode, Dr. Kate Kresge is joined by Dr. Eric Viegas, a naturopathic doctor who leads supplement safety and quality work at Fullscript, for a timely conversation about lead in protein powders and supplements. With headlines raising consumer concern, Dr. Viegas explains why trace lead can appear in products, why "detectable" doesn't automatically mean "dangerous," and how to interpret different regulatory thresholds like California's Prop 65 and the USP and ICH limits used in pharmaceutical quality systems. You'll learn how to think about cumulative exposure, which patients warrant extra caution, why plant-based proteins can be more vulnerable, and what to look for when choosing a safer protein powder.

3 Key Takeaways

• Context turns a number into a risk assessment. Modern testing can detect very small amounts of lead, so results need to be interpreted against toxicology-based thresholds and a patient's total exposure from diet, water, environment, and supplements. (Bandara 2020)
• Plants absorb what's in the soil. Rice grown near industrial areas has been shown to take up heavy metals from contaminated soil (Hasan 2022), which helps explain why some plant-based proteins carry higher risk. (Bandara 2020)
• Know when to test. CDC uses a blood lead reference value of 3.5 µg/dL to identify children with higher lead levels than most U.S. children. (CDC 2026) Dr. Viegas highlights pregnancy, pediatrics, and kidney disease as times to look more closely at exposure.

Guest: Dr. Eric Viegas, ND, is a naturopathic doctor and a leader in supplement safety and quality assurance at Fullscript, where he oversees contaminant screening, regulatory alignment, and enhanced testing initiatives. His work bridges pharmaceutical-grade toxicology standards with real-world clinical practice to support practitioner confidence and patient safety.

Clinical FAQ

How is Prop 65 different from USP and ICH limits?

Prop 65 uses large safety buffers designed to trigger warning labels, while USP <232> and ICH Q3D limits are toxicologically derived and widely used in pharmaceutical quality systems. . (OEHHA n.d.) (ICH 2022)

What should clinicians look for in a protein powder?

Third-party CGMP certification and batch-specific certificates of analysis, which show contaminant screening for the exact lot. Organic certification alone doesn't rule out heavy metals.

What else besides heavy metals matters?

Microbes, pesticides, residual solvents, phytates, and banned substances are also part of a complete protein powder quality review.

Timestamps

00:00 – Welcome and episode overview

01:48 – Why lead in protein powders is trending now

03:58 – Detectable doesn't always mean dangerous

04:30 – Interpreting lead amounts and cumulative exposure

07:45 – Why plant-based proteins carry higher heavy metal risk

10:55 – Certifications to look for

13:10 – Fullscript's enhanced testing and safeguards

15:10 – Assessing lead exposure in clinical practice

18:11 – What Dr. Viegas wants to change in the industry

20:02 – How to choose a safer protein powder

Ready to elevate your practice? This episode is sponsored by Fullscript, a comprehensive care delivery platform designed to support whole-person, integrative healthcare. Fullscript helps clinicians bring supplement dispensing, lab ordering, and patient education into one centralized workflow. For more practitioner education on supplements, nutrition, and evidence-informed clinical care, visit Fullscript Academy at academy.fullscript.com.

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.