How much lead in protein powder is safe?

California Prop 65 sets a Maximum Allowable Dose Level (MADL) of 0.5 µg/day for lead. Our concern levels assume 1 serving per day: Low (≤0.5 µg/serving), Moderate (0.5-1 µg/serving), High (1-5 µg/serving), Avoid (>5 µg/serving). We also show lead per 100g protein for comparing products with different serving sizes, but health risk is based on your actual daily intake.

How much lead in protein powder is safe?

California Prop 65 sets a Maximum Allowable Dose Level (MADL) of 0.5 µg/day for lead. Our concern levels assume 1 serving per day: Low (≤0.5 µg/serving), Moderate (0.5-1 µg/serving), High (1-5 µg/serving), Avoid (>5 µg/serving). We also show lead per 100g protein for comparing products with different serving sizes, but health risk is based on your actual daily intake (lead per serving).

Why do plant-based protein powders have more lead?

Plants absorb lead from soil more readily than animals. Plant-based proteins derived from peas, rice, and other crops can have higher lead content simply due to soil absorption, not manufacturing contamination. Organic farming doesn't eliminate lead from soil. Whey and casein proteins typically have lower lead levels.

Do protein powders contain heavy metals?

Yes, some protein powders contain detectable levels of lead, cadmium, arsenic, and other heavy metals. Consumer Reports 2025 testing found lead levels ranging from <0.01 µg to 7.7 µg per serving. Third-party certifications (NSF, Informed Sport) test for heavy metals but their limits vary significantly.

What is the Clean Label Project Purity Award?

The Clean Label Project Purity Award indicates a product is in the top third of tested products for purity. Products are tested for lead, pesticides, BPA, and other contaminants. The specific lead limit used for this award is not publicly documented.

Does NSF certification mean low lead?

Not necessarily. NSF Certified for Sport allows up to 10 µg/day of lead—20x California Prop 65's 0.5 µg/day limit. NSF certification ensures banned substance testing and manufacturing quality, but doesn't guarantee minimal lead content. Always check actual test data when available.

How do I find low-lead protein powders?

Look for independent testing data from Consumer Reports, Labdoor, or Clean Label Project. On product pages, we display both 'Lead per Serving' (determines your actual exposure) and 'Lead per 100g Protein' (for comparing products with different serving sizes). Choose products with 'Low' concern levels (≤0.5 µg/serving) to meet California Prop 65 standards.

Lead in Protein Powder: What Consumer Reports 2025 Found

Q: What is the Clean Label Project Purity Award?

The Clean Label Project Purity Award indicates a product is in the top third of tested products for purity. Products are tested for lead, pesticides, BPA, and other contaminants. The specific lead limit used for this award is not publicly documented.

Q: Does NSF certification mean low lead?

Not necessarily. NSF Certified for Sport allows up to 10 µg/day of lead—20x California Prop 65's 0.5 µg/day limit. NSF certification ensures banned substance testing and manufacturing quality, but doesn't guarantee minimal lead content. Always check actual test data when available.

Q: How do I find low-lead protein powders?

Look for independent testing data from Consumer Reports, Labdoor, or Clean Label Project. On product pages, we display both 'Lead per Serving' (determines your actual exposure) and 'Lead per 100g Protein' (for comparing products with different serving sizes). Choose products with 'Low' concern levels (≤0.5 µg/serving) to meet California Prop 65 standards.

Independent testing reveals concerning levels of lead contamination in some protein powders. We break down the Consumer Reports 2025 findings, explain California Prop 65 standards, and show how to choose lower-lead products using our normalized "lead per 100g protein" metric.

Why Lead Contamination Matters

Lead is a toxic heavy metal that accumulates in the body over time. Chronic exposure, even at low levels, can affect neurological development, cardiovascular health, and kidney function. Children and pregnant women are most vulnerable, but adults should also minimize exposure.

California Prop 65: The Benchmark

California's Proposition 65 sets a Maximum Allowable Dose Level (MADL) of 0.5 µg/day for lead. This is the strictest standard in the US and serves as our benchmark for 'low concern' products. Our concern levels assume 1 serving per day: Low (≤0.5 µg), Moderate (0.5-1 µg), High (1-5 µg), Avoid (>5 µg).

Our Concern Level Thresholds (Based on Prop 65)

We classify lead content into five levels based on absolute lead per serving (assuming 1 serving per day):

Level	Lead per Serving	Color Indicator
Low	≤0.5 µg	🟢 (Emerald)
Moderate	0.5-1 µg	🟡 (Yellow)
High	1-5 µg	🟠 (Orange)
Avoid	>5 µg	🔴 (Rose)
Not Tested	—	⚪ (Gray)

Tested Products Ranked by Lead Content

Interactive chart showing all tested protein powders ranked by lead content per serving. Color-coded by concern level. Click any bar to view product details.

🇺🇸 United States • 23 Products (incl. NSF-only)

Lead content per serving. Lower = safer

Show standards:

Loading chart...

SupplementMath.com

Lower values = safer. Bars are color-coded by concern level.

NSF Certified (≤10µg, no independent testing)

Understanding Lead Per Serving vs. Per 100g Protein

Consumer Reports and testing labs report lead 'per serving'—but serving sizes vary. A 35g whey serving might have 30g protein, while a 60g mass gainer serving has 50g protein. To compare fairly, we normalize by protein content. For example: 2.8 µg in a 30g-protein serving equals 9.3 µg/100g protein, while the same 2.8 µg in a 50g-protein serving equals only 5.6 µg/100g protein.

Lead per Serving determines your actual exposure. Lead per 100g Protein lets you compare products with different serving sizes.

Note: Health concern levels are based on absolute lead per serving, not the normalized 100g protein figure.

Consumer Reports 2025 Findings

In October 2025, Consumer Reports tested 23 protein powders and shakes for lead contamination. Key findings:

47% exceeded California Prop 65 limits for lead
Highest levels found:

Naked Nutrition Vegan Mass Gainer: 7.7 µg/serving (1,540% of Prop 65 limit)
Huel Black Edition: 6.3 µg/serving (1,290% of Prop 65 limit)
Garden of Life Sport Organic Plant-Based: 2.8 µg/serving (564% of Prop 65 limit)

Plant-based products had higher average lead levels than whey-based products
Chocolate flavors often had higher lead than vanilla from the same brand

Source: Consumer Reports October 2025 lead investigation

Plant-Based vs Whey: Why the Difference?

Plant-based protein powders consistently test higher for lead than whey or casein. This isn't due to manufacturing—it's due to soil absorption.

Plants absorb lead from soil: Pea protein, rice protein, and other plant crops naturally accumulate lead from soil
Organic doesn't eliminate lead: Organic farming reduces pesticide exposure but doesn't remove lead from soil
Concentration effect: Protein powders concentrate plant protein, which also concentrates any absorbed lead
Whey/Casein: Animal proteins have lower lead because cows don't bioaccumulate lead in their milk at significant levels

If you prefer plant-based protein: Look for products with independent testing data showing low lead levels below 0.5 µg/serving (California Prop 65 limit).

Third-Party Testing Sources

Consumer Reports (October 2025)

23 products tested with quantitative µg/serving results and Prop 65 percentages
consumerreports.org/lead

Labdoor

100+ protein powders tested; downloadable lab reports with heavy metal concentrations
labdoor.com

Clean Label Project (January 2025)

160 products (~83% of US market); binary pass/fail for Prop 65, Purity Award for top third
cleanlabelproject.org

Third-Party Certifications: For NSF, Informed Sport, and Informed Choice details (lead limits, testing requirements), see Protein Powder Certifications Explained →

How to Choose Lower-Lead Products

1. Check Independent Testing Data

Look for products with published lead measurements from Consumer Reports, Labdoor, or Clean Label Project. Target ≤0.5 µg/serving to meet California Prop 65 standards.

2. Consider Third-Party Certifications (With Caveats)

NSF, Informed Sport, and Informed Choice certifications indicate banned substance testing, but they do not guarantee minimal lead. NSF allows up to 10 µg/day (20x Prop 65). See our Protein Certifications Explained article for details.

3. Compare Using Normalized Data

On our product pages, we show both "Lead per 100g Protein" and "Lead per Serving." Use the per-100g-protein metric to compare products fairly—but remember health risk depends on lead per serving.

4. Favor Whey Over Plant-Based (For Lead Concerns)

Whey and casein proteins consistently test lower for lead than plant-based alternatives. If minimizing lead exposure is a priority, whey is generally the safer choice.

What About "No Detectable Lead"?

Some products report lead levels below detection limits (e.g., "<0.01 µg/serving"). Labdoor uses <0.01 µg to indicate "below detection." We treat these as effectively zero for our calculations.

Below detection ≠ zero: Trace amounts may still be present, just below the lab's ability to measure
Still safer: Products below detection are significantly safer than those with measurable levels
Best available: These are among the safest options when no product is truly lead-free

Recommendations Summary

If You Want the Lowest Lead:

Choose whey or casein over plant-based
Look for test data showing ≤0.5 µg/serving
Opt for vanilla over chocolate (chocolate often has higher lead)

If You Prefer Plant-Based:

Check for independent testing data confirming low lead (<0.5 µg/serving)
Consider rotating brands to minimize cumulative exposure

Third-Party Assurance:

Best: Actual test data showing ≤0.5 µg/serving
Good: NSF Certified for Sport or Informed Sport (but allows higher lead than Prop 65)

Disclaimer: The information on SupplementMath.com is for educational purposes only and is based on independent testing data from Consumer Reports, Labdoor, and Clean Label Project. We update our data as new testing becomes available. Always consult a healthcare professional if you have concerns about heavy metal exposure.