Published: October 27, 2025
Earlier this month, reports of lead contamination in 16 popular protein supplements shook the health and wellness community. Published on October 14th by Consumer Reports, a non-profit consumer advocate and watchdog organization, the report echoes the results from the Clean Label Project’s analysis earlier this year: almost half of the protein supplements tested may contain high levels of lead and other heavy metals. Both reports highlight the importance of third-party testing and certification of supplements, as these products currently fall into a regulatory grey area – and how important it is to improve that framework.
The Consumer Reports list of potentially unsafe products – and alternative products – is included below. Importantly, experts involved in both of these reports recommend consumers not panic, and instead be mindful of these risks as they adjust their consumption going forward.
Dietary supplements, especially protein powders or shakes, have taken America by storm in the last decade. While health influencers and some professionals have encouraged an increase in daily protein intake past existing medical recommendations, other professionals and nutrition experts consider it unnecessary to add supplements and specialized products to a standard diet – instead, encouraging consumers to consume a variety of whole foods to meet these nutrition goals. Since these supplements are regulated by the Food and Drug Administration (FDA) as food rather than drugs, supplement manufacturers are not required to prove their product does what they claim it does. As CBS News reported in 2022, this regulatory “Wild West” allows for supplements to be mislabeled, claim extraordinary effects, hide negative effects, and market medically significant substances without testing for safety and efficacy. That job is often outsourced to third-party organizations instead.
The contaminant at the center of the latest reporting is lead, a naturally occurring heavy metal used extensively in American manufacturing and infrastructure – though that usage, especially in leaded gasoline and consumer products, was greatly limited by emerging Environmental Protection Agency (EPA) guidelines in the 70’s. The health risks posed by lead vary with exposure, but as a carcinogen, there is technically no completely “safe” level of lead exposure. Due to how difficult it is to totally avoid any lead exposure, though, government agencies like the FDA recommend a “Closer to Zero” approach: limiting unnecessary exposure and avoiding high concentrations of lead.
Risks to health increase with long-term (chronic) exposure, such as lead paint or water pipes in some homes built before 1978, or in manufacturing settings. According to the World Health Organization (WHO), chronic exposure to lead can negatively affect development, affect behavior and learning, and cause severe organ damage in children. Adults are at risk for long-term injury or organ diseases like hypertension or renal failure, as well as anemia and injury to the central nervous system. Lead can be absorbed and accumulate in the blood and bones, with lead staying in the bones for decades. While environmental sources of lead like piping, paint, manufacturing byproducts, bullets, and older toys can all contribute to chronic exposure, dietary exposure is often neglected in both conversation and regulation. This can happen for a variety of reasons, including contamination during the packaging of food or even the contamination of the soil in which ingredients grow.
The FDA’s assessment of dietary lead exposure suggests the average American consumes about 5.3 micrograms of lead per day. The interim guidelines suggest that infants not consume more than 2.2 micrograms per day, and that adult women of childbearing age not consume more than 8.8 micrograms per day in order to avoid chronic lead poisoning. An FDA spokesperson believes the “less than 8.8 micrograms per day” benchmark can be applied to all adults, according to Consumer Reports. California’s Proposition 65, the “Safe Drinking Water and Toxic Enforcement Act of 1986,” requires that any product shown to contain ingredients posing a significant risk of cancer, birth defects, or reproductive harm receive a warning label. Lead’s “maximum allowable dose level” for reproductive toxicity under this regulation is 0.5 micrograms per day, and 15 micrograms per day is the “safe harbor” threshold for cancer – after which the risk of developing cancer increases.
That is where the concern in these reports comes from: though their methodology differed slightly, both found many of these products potentially in violation of Proposition 65 safety thresholds for labeling. The Clean Label Project’s 2024-25 Powder Category Report found high lead levels of lead, cadmium, arsenic, and mercury over safety thresholds in 47% of the 160 products tested, from “70 of the top-selling brands” in the country, performing 35,862 individual product tests. 79% of organic protein supplements tested contained lead over this threshold, with 41% containing more than twice the allowable amount under Proposition 65. 77% of plant-based protein supplements were over the lead threshold, compared to 28% of whey-based protein supplements. Notably, as well, chocolate-flavored products were much more likely to contain lead over the threshold, at 65% (with 29% containing over twice the allowable amount). The Clean Label Project also created the “Clean 16” list of products that had no detectable levels of lead, mercury, arsenic, or cadmium.
The Consumer Reports analysis tested 23 protein supplement products, finding a “concerning” level of lead in 16 – over two-thirds of the supplements. Proposition 65 thresholds were also considered in this report, with their threshold for concern being any product that would surpass 0.5 micrograms of lead in a single serving. Recommendations were also based on the assumption that only one serving was consumed per day, even when a product recommended more than one serving per day. Of the 16 products that tested over this limit, six tested over twice the level of concern, and two tested so high that Consumer Reports recommended they be avoided entirely: Huel’s Black Edition (Chocolate) contained over 15 times the lead level of concern at 6.3 micrograms per serving, and Naked Nutrition’s Vegan Mass Gainer (Vanilla) contained over 12 times the lead threshold at 7.7 micrograms per serving.
For the remaining 14 products of concern, Consumer Reports recommends limiting use throughout the week to less than once per day or less than once per week, while also highlighting seven products that are “better choices for daily consumption”: products that tested below the 0.5 microgram threshold, like Muscle Tech’s 100% Mass Gainer Vanilla Milkshake – which had no detectable levels of lead. Similar to the Clean Label Project results, this analysis found that aside from some exceptions, “products made with plant-based proteins generally tested higher for lead than those using meat- or dairy-based sources.”
Regulations for these products feel increasingly important, with both reports recommending changes to the current federal regulatory framework. No federal guidelines limit how much lead can be present in protein powders, and determining whether or not a product could be harmful to human health is mostly left to voluntary testing and reporting by the manufacturers themselves. Both California and Maryland have passed legislation requiring transparency in labeling, and in May, Scientific American reported that California’s Proposition 65 has already pressured many companies to proactively test for and remove hazardous chemicals rather than re-label products with warnings. Though these companies and nonprofit groups like the National Sanitation Foundation have criticized the Proposition 65 guidelines and “level of concern” metric as “too conservative” and “overstating risk,” the results of state-level regulation show that better compliance is possible, and that a federally-established threshold similar to California’s could lead to industry-wide reforms and better outcomes for supplement consumers across the country.
Until such reform, experts recommend only using protein supplements tested by third-party safety groups.
Products to Avoid:
- Huel: Black Edition (Chocolate)
- Naked Nutrition: Vegan Mass Gainer (Vanilla)
One Serving Per Week:
- Garden of Life: Sport Organic Plant-Based Protein (Vanilla)
- Momentous: 100% Plant Protein (Chocolate)
Multiple Servings Per Week:
- MuscleMeds: Carnivor Mass (Chocolate Peanut Butter)
- Optimum Nutrition: Serious Mass (Vanilla)
- Jocko Fuel: Mölk Protein Shake (Chocolate)
- Vega: Premium Sport Plant-Based Protein (Chocolate)
- Quest: Protein Shake (Chocolate)
- Orgain: Organic Plant-Based Protein Powder (Vanilla Bean)
- Optimum Nutrition: Gold Standard Protein Shake (Chocolate)
- Equip Foods: Prime Protein (Chocolate)
- PlantFusion: Complete Protein (Creamy Vanilla Bean)
- Ensure: Plant-Based Protein Nutrition Shake (Chocolate)
- Muscle Milk: Pro Advanced Nutrition Protein Shake (Chocolate)
- KOS: Organic Superfood Plant Protein (Vanilla)
One Serving Per Day (Better Choices):
- Owyn: Pro Elite High Protein Shake (Chocolate)
- Transparent Labs: Mass Gainer (Sweet Vanilla)
- Optimum Nutrition: Gold Standard 100% Whey (Chocolate)
- BSN: Syntha-6 Protein Powder (Vanilla Ice Cream)
- Momentous: Whey Protein Isolate (Vanilla Flavor)
- Dymatize: Super Mass Gainer (Gourmet Vanilla)
- Muscle Tech: 100% Mass Gainer (Vanilla Milkshake)
