A new investigation conducted by Consumer Reports found that out of 23 protein powders and ready-to-drink shakes it tested, over two-thirds of the products contained unsafe levels of lead in a single serving, according to Consumer Reports' food safety experts. Some samples contained over 10 times the amount considered a safe daily intake of lead by the organization's experts.
This echoes a 2024-25 report by the nonprofit organization Clean Project Label, which concluded that out of 160 tested protein powders, 47% exceeded California Proposition 65 safety thresholds for toxic metals. Plant-based protein powders in particular had three times the amount of lead found in whey-based powders, while chocolate powders had four times more than vanilla. Organic powder also contained three times more lead and twice as much cadmium, another metal, as non-organic versions.
Although these reports may be alarming, it's essential to understand their context. To find out if heavy metals in protein powders are actually something we should be concerned about, we reached out to dietitians for their expert insights and more information on how to choose a safe protein powder.
The report on heavy metals in protein powders
Knowing which studies and reports to trust can be tricky. According to sports dietitian Kelly Jones, the Clean Project Label study was an independent report not published in a peer-reviewed journal and did not go through the institutional review board approval process. “Since Clean Label Project did not disclose any of the protein powders tested but recommends only brands that pay for their independent certification, I do not recommend my clients, audience or consumers as a whole worry about this study,” she explains.
Clara Nosek, a registered dietitian, points out that the Clean Label Project did not disclose its methodology or a hazard quotient, which tells you how much of the contaminant was used to assess the potential health risks associated with its exposure. “The lack of methodology means their findings cannot be reproduced, which does send up red flags from a scientific methods perspective,” Nosek warns.
You’ve probably heard the term “the dose makes the poison,” which means that in order to deem an ingredient harmful, there needs to be a specific dosage mentioned as well. Keep in mind that too much of anything, even water, can be bad for you. It’s important to understand that detection of an ingredient does not equal immediate health risk.
“Just because a chemical is present, doesn’t mean it’s harmful in the amount present,” explains Nosek, adding that the study does not “explicitly state whether or not the concentration of heavy metals found in the powders posed any direct health risks -- which means it’s clearly an emotional manipulation.”
A solid study should be transparent in its methodology so others understand the scientific method and data the author used to reach their conclusions. Additionally, a study should be peer-reviewed, meaning experts in the field have evaluated its findings, research methods, citations and contribution to existing knowledge on the topic. This is a rigorous process since they must critically review each piece of information before validating it. The author also remains anonymous to minimize any potential bias during the evaluation. If it passes the peer review process, it’s then published in a scholarly journal.
If you want to know if a study should or shouldn’t be trusted, Nosek advises looking out for these red flags:
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