Protein powders are ubiquitous in today’s wellness and performance landscape, used not only by athletes but also by individuals who seek to support healthy aging, as well as muscle and metabolic health. However, not all scoops are created equal. The difference between a clean, clinically supportive product and one that may introduce hidden contaminants often comes down to sourcing, processing, and independent verification. 

The Hidden Risk of Heavy Metals 

Recently, Consumer Reports revealed that a substantial portion of commercial protein powders may contain elevated levels of heavy metals (such as lead, cadmium, arsenic, and mercury). The testing initiative included 23 protein powders and shakes from popular brands, with two to three distinct samples of each product blind-coded and tested in an independent laboratory. About two-thirds of the tested products contained lead levels in a single serving that exceeded 0.5 micrograms per day, with the highest lead readings at approximately 7.7 and 6.3 micrograms per serving. Three of the products also exceeded levels of concern for cadmium and arsenic, suggesting that contamination in protein powders could potentially lead to a significant cumulative heavy-metal burden.

Even low-level chronic exposure to heavy metals can carry significant health risks. Heavy-metal toxicity has been associated with impaired cognitive, cardiometabolic, kidney, bone, endocrine, and immune health. While a single serving may not cause acute toxicity, repeated daily use over months or years may significantly increase the cumulative burden. 

Choosing High-Quality Protein Powders

Selecting a clean, reliable protein powder requires more than scanning the label. To minimize the risk of contamination and ensure product quality, consider the following criteria:

• Verify Food and Drug Administration (FDA) current Good Manufacturing Practice (cGMP) compliance. Companies that follow cGMPs adhere to rigorous standards for quality, consistency, and safety throughout the manufacturing process.
• Assess raw material quality and sourcing. Look for brands that use high-quality inputs (such as grass-fed, non-GMO, and organic ingredients) and that clearly disclose their sourcing, vendor qualification procedures, and manufacturing methods.
• Prioritize products manufactured in FDA-inspected facilities that maintain robust internal quality-control systems. Certifications from organizations such as the National Sanitation Foundation (NSF), United States Pharmacopeia (USP), International Organization for Standardization (ISO), Over-the-Counter Drug GMPs (OTC GMPs), or the Therapeutic Goods Administration (TGA) further indicate adherence to elevated manufacturing standards.
• Select products that undergo independent third-party contaminant testing.
  • NSF Certified for Sport® ensures testing for heavy metals, microbial contamination, and banned substances.
  • ISO-accredited laboratory testing confirms potency, purity, identity, and absence of contaminants through labs formally accredited to international ISO standards.
• Request a Certificate of Analysis (COA). A reputable company should provide a lot-specific COA showing actual test results for heavy metals (including lead, cadmium, arsenic, and mercury) as well as microbial contaminants and ingredient potency.

While protein supplementation may play an important role in supporting muscle and metabolic health and healthy body composition, not every protein powder offers the same level of safety and quality. Choosing products that are third-party tested, transparent about sourcing, and free from heavy metal contamination can help access the nutritional benefits while minimizing the hidden risks.

Learn more about protein and its role in overall health: 

Impacts of Beef Protein Supplementation on Body Composition and Performance

Effects of High Protein Intake on Aging, Metabolic Health, and Weight

Quality Matters: Understanding Protein Digestibility Score

Timing is Everything: Protein Supplementation in Exercise Recovery

By Antonia Toupet, PhD