“Toxic Contaminant Levels in Commercial Protein Powders: Clean Label Project Protein Study 2.0”

Organization: Clean Label Project
Publication Year: 2024 Update (original category review launched 2018)
Scope: 160+ of the best-selling protein powders from 70+ brands
Testing Methods: Third-party ISO-accredited lab testing for heavy metals, pesticides, plasticizers (e.g., BPA/BPS), residual solvents, and general purity markers. Testing included quantification of contaminants per serving and per daily max exposure.

This large-scale investigation evaluated contamination risks across the U.S. protein powder market. Products included whey, casein, plant-based, collagen, egg-based, and meal-replacement powders. Testing compared results against established state and federal safety thresholds (including California Prop 65 limits).

Key conclusions:

Nearly half of all protein powders contained levels of heavy metals that exceeded one or more safety thresholds.

• 47% of products exceeded at least one regulatory or industry threshold for heavy metals such as arsenic, cadmium, lead, or mercury.
  
• Contamination often stemmed from agricultural sourcing — especially plant-derived proteins grown in contaminated soil.
  
  

Plant-based protein powders showed the highest levels of contaminants overall.

• Many plant-based products scored dramatically worse than whey-based powders.
  
• Higher concentrations were found particularly in pea, rice, and hemp proteins.
  
• Chocolate-flavored plant proteins had the highest contaminant load due to cocoa sourcing.
  
  

BPA/BPS contamination was widespread — including in products labeled “BPA-free.”

• Over 70% of products tested positive for measurable levels of plasticizers.
  
• Several “BPA-free” labeled products still contained BPA or BPS, suggesting leaching from packaging or supply-chain equipment.
  
  

Some protein powders contained measurable levels of pesticides and residual solvents.

• Although typically below federal limits, several samples showed detectable levels of agrichemical and solvent residues.
  
• Products using non-organic plant materials had higher pesticide positivity rates.
  
  

Contamination levels varied over 500-fold between the cleanest and dirtiest products.

• A consumer selecting the “dirtiest” product could ingest hundreds of times more contaminants compared to choosing the cleanest product.
  

Organic certification did not guarantee lower contamination.

• Surprisingly, some organic-labeled products were among the worst performers in heavy-metal contamination.
  
• The study emphasized that geographic soil quality, not just organic farming practices, strongly influences contaminant levels.
  
  

Overall industry transparency is poor; only a small fraction of brands publish third-party contaminant tests.

• Clean Label Project found that most brands do not routinely test for heavy metals, pesticides, or BPA.
  
• Even fewer publicly release their results to consumers.
  
  🔗 Original study: https://cleanlabelproject.org/protein-study-2-0/
  
  
  
  

“Protein Powders & Shakes Contain High Levels of Lead” — Consumer Reports (2025)

Organization: Consumer Reports
Date: October 2025 (published in press release + full testing article) Consumer Reports Advocacy
Sample size & scope: 23 popular protein powders and shakes — including dairy-, beef-, and plant-based products.
Testing methods: Independent third-party laboratory testing for heavy metals (lead, plus also checking for other metals like cadmium and arsenic). Results compared against CR’s “safety threshold” of 0.5 µg lead per serving — a precautionary limit based on strict regulatory guidelines.

Key conclusions

More than two-thirds of tested protein powders/shakes exceeded CR’s lead safety threshold (0.5 µg/serving).

• “Over two-thirds” of the 23 products had lead levels per serving higher than what CR considers a safe daily limit.
  
• Some products exceeded the threshold by a large margin — in certain cases, 10× or more above CR’s limit.
  

Plant-based protein powders tended to have the highest lead levels.

• The highest lead readings were found in powders using plant proteins (like pea or rice), compared with dairy- or meat-based powders.
  
• Example: One serving of a tested plant-based powder contained 7.7 µg lead — many times over CR’s “level of concern.”
  

Some powders also contained other heavy metals (cadmium, inorganic arsenic) at concerning levels.

• In addition to lead, a subset of products had detectable levels of cadmium and inorganic arsenic — both known toxicants.
  
• This underscores that lead was not the only contaminant risk — heavy-metal contamination may be more widespread.
  

The supplement-regulation gap makes contamination a systemic risk.

• Because dietary supplements are not pre-approved by regulators before sale (unlike drugs or conventional food), heavy-metal contamination remains a largely unregulated externality.
  
• CR calls for stricter regulation and for manufacturers to routinely test and publish contaminant data for protein powders and shakes.
  

🔗 Original report:

“Protein Powders and Shakes Contain High Levels of Lead” — Consumer Reports, Oct 2025 Consumer Reports Advocacy