Washington, DC—Protein powder is the latest nutrition product to come under fire, with alarming headlines in mainstream media warning consumers:

_Cancer-causing ingredients found in popular protein powders (Daily Mail)
_Your Protein Powder Could Contain Toxic Metals, Report Finds (Men's Fitness)
_Lead and cadmium found in muscle-building protein powders, report says (CNN)

The headlines were sparked by a report from the Clean Label Project (CLP). In its 2024-25 Protein Powder Category Report, the national non-profit says, "The Clean Label Project was founded with a mission to uncover the hidden risks of environmental contaminants and toxins lurking in everyday products."

About the protein powder report

For the report, CLP says 160 products from 70 of the top-selling brands (representing 83% of the market) were tested. CLP reported:

  • Of the products tested, 47% exceeded California Proposition 65 safety thresholds for toxic metals.
  • Organic products, on average, had three times more lead and twice the amount of cadmium compared to non-organic products.
  • Plant-based protein powders had three times more lead than whey-based alternatives.
  • Chocolate-flavored protein powders contained four times more lead than vanilla.

Leading trade groups respond

CRN: Report's methodology warrants scrutiny

Andrea Wong, Ph.D., Senior Vice President, Scientific & Regulatory Affairs, for the Council for Responsible Nutrition (CRN), issued a statement stressing that CRN supports efforts to ensure the safety and quality of dietary supplements, but that reports like those issued by the Clean Label Project often lack critical context and can end up misleading consumers.

"First, it is important to emphasize that the detection of contaminants, as highlighted in this report, does not inherently equate to a health risk," Dr. Wong said. Modern analytical techniques can detect even trace levels of naturally occurring elements, such as heavy metals, which are present in soil, air, and water. These trace levels are often well below established safety thresholds set by federal agencies like the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA).

"California Proposition 65, frequently referenced in CLP’s findings, imposes limits that are uniquely stringent and not aligned with federal guidelines. For example, it imposes a 1,000-fold safety factor below the level at which no harmful effects have been observed, and it requires labeling of products over that amount, not a ban on them. While CLP’s intentions to protect consumers are commendable, the lack of harmonization with FDA or EPA standards can result in unnecessary consumer alarm. CRN has consistently advocated for science-based federal standards that balance consumer safety with practicality and consistency across all states. Federal agencies regulate the manufacturing of food and dietary supplements, including testing and monitoring protocols for heavy metals."

Dr. Wong said the methodology of CLP's report also warrants scrutiny. "CLP has not provided sufficient transparency regarding how products were selected, the criteria for contamination thresholds, or the interpretive framework for their findings. Without such clarity, consumers and industry stakeholders cannot fully evaluate the validity of the claims. CRN urges CLP to publish its findings in peer-reviewed journals and provide recommendations grounded in scientific evidence."

Looking ahead, Dr. Wong said that as we move toward ensuring safety and transparency, a unified regulatory approach that upholds reasonable, evidence-based standards should be the focus. "Aligning state initiatives like Proposition 65 with federal guidelines would reduce confusion for consumers and manufacturers while maintaining public safety. CRN and its members remain committed to collaborating with stakeholders to promote rigorous, transparent, and uniform safety standards across the dietary supplement industry.”

NPA: This is a "sham of a study"

The Natural Products Association (NPA) said the study is "just another dirty trick" and maintains that the report "falsely alleges there is a significant presence of contaminants in some products and that it could pose a serious safety threat to consumers." NPA said CLP denied a request by NPA to disclose the methodology and the data behind the allegations. 

NPA President and CEO Daniel Fabricant, Ph.D., had a strong response, says CLP is "full of it" and "this so-called study is nothing but hot air." He added, "We are demanding that they disclose this so-called study’s methodology instead of peddling misinformation and profiting from referred products to online retailers listed on its website."