The protein powder market has exploded in recent years, reaching over $32 billion globally, with consumers increasingly treating these supplements as daily nutritional staples.

Yet recent investigations reveal a troubling reality: many popular protein powders and ready-to-drink shakes contain concerning levels of lead and other toxic heavy metals that accumulate in the body over time.

Two separate investigations conducted in 2024 and 2025 found widespread contamination across the industry. Consumer Reports tested 23 popular protein products and discovered that more than two-thirds contained more lead in a single serving than their experts consider safe to consume in an entire day. Some products exceeded that threshold by more than tenfold.

Meanwhile, the Clean Label Project analyzed 160 protein powders from 70 brands and found that 47% exceeded California Proposition 65 safety thresholds for toxic metals.

The findings represent a worsening trend. When Consumer Reports first examined protein powders 15 years ago, contamination levels were lower and fewer products contained detectable amounts of lead. The average lead content has increased since then, even as the industry has grown and rebranded itself around health and wellness.

Plant-based and organic products show highest contamination

Contrary to what health-conscious consumers might expect, organic and plant-based protein powders showed the highest contamination levels. Organic products contained three times more lead and twice as much cadmium compared to non-organic alternatives. Plant-based powders showed three times more lead than whey-based products.

Even flavor choices matter. Chocolate-flavored protein powders contained four times more lead than vanilla varieties and 110 times more cadmium. This occurs because dark chocolate and cacao naturally contain elevated levels of heavy metals absorbed from soil during growth.

The contamination stems from two primary sources. Heavy metals occur naturally in volcanic rock and contaminated soils, and certain crop plants efficiently extract these metals from the ground and concentrate them in edible portions. When volcanic rock erodes, heavy metals seep into local soil and water supplies.

Additionally, fossil fuel combustion releases heavy metals into the air that eventually settle into soil, while some fertilizers, herbicides and pesticides contain heavy metals that further contaminate growing areas.

Whey and dairy-based protein products generally showed lower contamination levels because dairy cows filter out most heavy metals before they reach milk. However, even among whey products, half still contained enough lead that experts advise against daily consumption.

Serious health risks from chronic exposure

The World Health Organization identifies lead as one of 10 chemicals of major public health concern and states there is no known safe blood lead concentration. Lead exposure causes more than 1.5 million deaths globally each year, primarily through cardiovascular effects including increased risk of high blood pressure, heart attacks and strokes.

In children and developing fetuses, lead permanently affects brain development, resulting in reduced IQ, behavioral problems, reduced attention span and learning difficulties. Lead exposure during pregnancy can cause reduced fetal growth and preterm birth. In adults, lead damages the kidneys, impairs reproductive function and causes anemia.

Cadmium poses equally serious threats. Classified as a probable human carcinogen by the Environmental Protection Agency, cadmium accumulates in the kidneys, liver and bones.

Chronic exposure causes kidney dysfunction, bone demineralization, reproductive problems, cardiovascular disease and diabetes. The body eliminates cadmium extremely slowly, meaning years of low-level exposure from daily protein shake consumption could result in dangerous accumulation.

Three products in the Consumer Reports testing exceeded their level of concern for both lead and the carcinogenic heavy metals cadmium and inorganic arsenic. Two plant-based powders contained enough lead that experts advised against consuming them at all.

Regulatory gaps leave consumers vulnerable

The supplement industry operates under regulations separate from other food and drug products. The FDA does not test dietary supplements or verify their ingredients before they reach store shelves.

While the agency issued interim reference levels of 2.2 micrograms of lead per day for children and 8.8 micrograms for women of childbearing age earlier this year, these serve as voluntary targets for industry rather than enforceable limits.

California’s Proposition 65 remains the most progressive regulatory framework, requiring businesses to warn consumers about significant exposure to cancer-causing chemicals and reproductive toxins. Consumer Reports used California’s standard of 0.5 micrograms of lead per day as their safety threshold, which includes a wide safety margin. This conservative approach reflects the scientific consensus that any lead exposure carries risk.

The FDA told Consumer Reports it monitors contaminants through its toxic element compliance program and will review the testing findings to inform future testing and enforcement activities. However, the lack of mandatory testing before products reach consumers means contaminated supplements continue circulating in the market.

Making safer choices

Experts emphasize that occasional consumption of most tested products poses minimal risk, as harmful health effects primarily result from repeated exposure at high doses. The greatest danger comes from daily use over months and years, allowing heavy metals to accumulate in the body.

Consumers can reduce exposure by choosing whey or animal-based protein products, which generally contain lower heavy metal levels than plant-based alternatives. When selecting plant-based options, vanilla-flavored products typically contain less contamination than chocolate. Rotating between different protein sources and brands also limits cumulative exposure from any single product.

For products showing especially high heavy metal content, using them sporadically rather than daily significantly reduces exposure. Consumers should also consider that serving sizes vary between products, so understanding what constitutes one serving helps manage consumption appropriately.

Maintaining a varied diet rich in nutritious whole foods remains the best strategy. Research shows good overall nutrition can help protect against effects of contaminant exposure. Rather than relying heavily on protein supplements, consumers might consider whether they actually need supplementation or if dietary protein from diverse food sources better serves their health goals.

The protein supplement industry’s rapid growth has outpaced safety oversight, leaving consumers to navigate risks on their own. Until more comprehensive testing requirements and enforceable safety limits emerge, awareness and careful product selection remain the primary tools for minimizing exposure to these toxic heavy metals that have no place in products marketed as health enhancers.