The Truth: Are heavy metals in protein powders?

December 8, 2025 •

4 min read

In early 2025, a report from the Clean Label Project revealed that nearly half of the most popular protein powders tested contained detectable levels of heavy metals like lead and cadmium. This discovery has raised serious questions about consumer safety and prompted many to ask: are heavy metals in protein powders a genuine concern for frequent users?

Quick Summary

Studies have detected heavy metals like lead, cadmium, and arsenic in many protein powders, especially plant-based and chocolate-flavored types. Contamination can occur from soil absorption and manufacturing, making third-party testing crucial for safer product selection.

Key Points

Heavy Metals Found: Lab tests by groups like the Clean Label Project have detected toxic heavy metals, including lead, cadmium, and arsenic, in many protein powders.
Plant-Based Higher Risk: Plant-based protein powders tend to have higher levels of heavy metals than whey or egg-based products due to environmental absorption.
Chocolate Flavors Increase Risk: Chocolate-flavored protein powders often contain significantly higher heavy metal levels, particularly cadmium, due to contaminants in cocoa.
Sources of Contamination: Heavy metals enter protein powders through raw material absorption from contaminated soil and water, as well as via manufacturing equipment.
Seek Third-Party Testing: To minimize risk, choose brands with independent certifications from organizations like NSF Certified for Sport or the Clean Label Project.
FDA Oversight is Limited: The FDA does not regulate dietary supplements as strictly as drugs, meaning companies are primarily responsible for ensuring product safety and purity.
Diversify Your Diet: Supplementation should not replace whole food sources of protein, such as meat, eggs, and legumes, to minimize reliance on a single source.

Why heavy metals appear in protein powders

Heavy metals can make their way into protein powders through various stages of production, from the raw material source to the final manufacturing process. Because protein supplements are classified as dietary supplements, they are not regulated by the FDA in the same stringent way as food and pharmaceuticals, leaving more responsibility on manufacturers and consumers.

Natural sources and absorption

One of the most significant entry points for heavy metals is through the environment. Elements like lead, cadmium, and arsenic are naturally present in the Earth's crust and soil. Plants can absorb these heavy metals as they grow, which is particularly relevant for plant-based protein powders derived from sources like pea, rice, and hemp. The type of soil, water, and even the air quality in the cultivation area can influence the level of contaminants absorbed. This also explains why organic protein supplements, if sourced from contaminated soil, might contain higher levels of heavy metals than non-organic counterparts, a surprising finding from the Clean Label Project.

Manufacturing and flavoring

Manufacturing and processing are another potential source of contamination. Heavy metals can leach into the final product from poorly maintained or inappropriate processing equipment. Contaminants can also be introduced through various ingredients and additives, such as the cocoa used in chocolate-flavored powders. Cacao plants are known to absorb heavy metals, and this is why chocolate-flavored protein powders have often shown higher levels of lead and cadmium than vanilla varieties in independent testing.

The most commonly found heavy metals

Research from organizations like the Clean Label Project and Consumer Reports has identified several heavy metals in protein powders. The most common are:

Lead (Pb): A neurotoxin known to cause cognitive damage, especially in children, and linked to high blood pressure and kidney damage in adults.
Cadmium (Cd): A carcinogen that can damage the kidneys, liver, and bones with long-term exposure.
Arsenic (As): A carcinogen linked to skin lesions and developmental issues, with higher levels sometimes found in rice-based products.
Mercury (Hg): A toxic metal that can cause neurological, renal, and cardiovascular damage with sufficient exposure.

Plant-based vs. whey: a comparison

Independent testing has revealed significant differences in contamination levels between plant-based and animal-based protein powders. A comparison based on findings from the Clean Label Project highlights these distinctions:


Feature	Plant-Based Protein Powders	Whey-Based Protein Powders
Heavy Metal Levels	On average, higher levels of lead and cadmium.	Typically, lower levels of heavy metals.
Lead Levels	Found to contain three times more lead than whey-based options in some studies.	Showed lower lead concentrations on average.
Cadmium Levels	Contained five times more cadmium than whey-based options in testing.	Generally lower cadmium content.
Source of Contamination	Absorbed from soil and water during plant cultivation.	Contamination risk is lower, possibly diffused through the animal's digestive system.
Organic Label	Organic versions often showed higher heavy metal levels than non-organic plant-based products, likely due to soil composition.	Less affected by the 'organic' vs. 'non-organic' difference regarding heavy metals.

How to choose a safer protein powder

To minimize exposure to heavy metals, consumers can follow several practical steps. Since FDA regulation is limited for supplements, selecting responsible brands is key.

Key steps for selecting a safer protein powder:

Look for Third-Party Testing: Seek products with certifications from independent organizations like NSF Certified for Sport®, Informed-Sport, or the Clean Label Project. These certifications indicate that the product has been tested for contaminants and meets safety standards. Many reputable brands will provide Certificates of Analysis (COAs) upon request or on their websites.
Check Flavor: Consider opting for vanilla or unflavored protein powders, as chocolate versions have been consistently linked to higher heavy metal levels due to the cocoa content.
Consider Whey or Egg Protein: If dietary preferences allow, whey or egg-based proteins tend to have lower heavy metal levels than plant-based options.
Diversify Your Protein Sources: Don't rely solely on protein powders for your protein intake. Ensure you're getting protein from a variety of whole foods like lean meats, dairy, legumes, and nuts to minimize exposure from any single source.
Research the Brand: Choose reputable brands known for transparency and strict quality control. Brands that openly share information about their sourcing and manufacturing practices are generally more trustworthy.

For more detailed findings and to check specific product ratings, consult the Clean Label Project website, a non-profit organization that provides comprehensive test results on consumer products like protein powders.

Conclusion

The presence of heavy metals in protein powders is a documented issue, with contamination stemming from environmental factors and manufacturing processes. While many studies have indicated that, for most consumers, the health risk from typical intake is minimal, frequent or high-volume use raises long-term concerns, particularly for vulnerable populations. The key takeaway is that not all protein powders are created equal, and some types—specifically plant-based and chocolate-flavored varieties—pose a higher risk of contamination. By prioritizing third-party certifications, choosing certain flavors, and diversifying protein sources, consumers can make more informed choices and significantly reduce their exposure to heavy metals while still benefiting from protein supplementation.

Frequently Asked Questions

Studies have found lead, cadmium, arsenic, and mercury in many protein powders. The presence and levels of these contaminants can vary significantly by product and brand.

Plants absorb minerals and elements, including heavy metals, from the soil and water they are grown in. Since plant-based powders are made from concentrated plant matter, they are more susceptible to containing higher levels of these soil-borne contaminants compared to animal-derived proteins.

Yes, it can. Chocolate-flavored protein powders, in particular, have been found to contain higher levels of lead and cadmium. This is likely due to the cocoa used for flavoring, as cacao plants naturally absorb heavy metals from the soil.

Look for products that are third-party tested and certified by independent organizations such as NSF Certified for Sport, Informed-Sport, or Clean Label Project. These certifications confirm that the product has been screened for contaminants, including heavy metals.

Reputable brands will be transparent about their testing practices. Look for certifications on the product label or visit the brand's website to find a Certificate of Analysis (COA), which details the lab test results for each product batch.

The FDA regulates supplements differently than food and drugs, and there is no mandatory testing for safety and contaminants like heavy metals before a product hits the market. The responsibility falls primarily on the manufacturer to ensure safety.

Long-term consumption of heavy metals can lead to health problems, including kidney damage, neurological issues, and an increased risk of certain cancers. The risk is generally higher for frequent users, but no level of lead is considered safe.

No. A surprising finding from the Clean Label Project was that organic protein powders, on average, had higher levels of heavy metals than non-organic products. This is attributed to soil quality, not the 'organic' certification.