Lead and heavy metals in protein powder

In October 2025, Consumer Reports tested 23 protein powders and shakes. More than two-thirds had more lead in a single serving than CR's experts say is safe to have in a whole day. Plant-based products were the worst, averaging nine times the lead of dairy-based ones. Every plant-based powder CR tested was made mainly from pea protein. No hemp protein was tested. Here's what the numbers mean, where lead comes from, how to read a heavy-metals test, and Cantein's own results.

What Consumer Reports found

• 23 products from dairy, beef, and plant sources, two to four lots each.
• About 70% had more than 120% of CR's "level of concern" for lead in one serving. That level is 0.5 micrograms (µg) a day.
• Plant-based products averaged nine times the lead of dairy-based ones, and twice that of beef-based ones.
• Two plant-based powders were so high CR advised not using them at all: 7.7µg and 6.3µg of lead per serving.
• Even among dairy products, half had enough lead that CR advised against daily use.
• Cadmium and inorganic arsenic turned up in a few products. Mercury wasn't detected at levels of concern in any.
• CR found no meaningful difference between vanilla and chocolate in this round, though earlier tests have pointed to cocoa as a source of heavy metals.

Where the lead comes from

Lead occurs naturally in the earth's crust, and human activity such as industry, old pesticides, and leaded fuel has added more to soil and water. Plants take some of it up as they grow. So any plant food carries a trace, and a concentrated plant protein can carry more, because you're eating a lot of plant in one scoop.

Processing can add more. CR noted lead could enter pea protein during dehulling, grinding, or the wet process used to separate protein from starch, depending on the equipment. Where the crop is grown matters too. Much of the pea protein used in the US has historically been imported, and many brands don't say where theirs comes from.

Hemp has its own version of this problem. It is efficient at pulling metals from soil, so much so that it's been studied as a way to clean up contaminated land. In one field trial on polluted soil, hemp seeds took up relatively high cadmium and nickel but little lead (Linger et al., 2002). For hemp, cadmium matters as much as lead, and so does where it's grown.

The benchmarks, and why they differ

No safe level of lead exposure has been identified. These are lines for deciding when exposure becomes a concern, and the strictest, Prop 65, is what most buyers now use to compare powders. The FDA's reference level covers your whole diet, so a powder using a big share of it leaves less room for everything else you eat.

How to read a heavy-metals result

Labs usually report metals as a concentration: parts per million (ppm, the same as mg/kg) or parts per billion (ppb, the same as µg/kg). What matters for you is the amount per serving. To convert:

• From ppb: µg per serving = ppb × serving size in grams ÷ 1,000.
• From ppm: µg per serving = ppm × serving size in grams.

Example: a powder at 20ppb lead with a 35g scoop has 20 × 35 ÷ 1,000 = 0.7µg of lead per scoop, or 140% of the Prop 65 level. The same powder at a 25g serving would be 0.5µg. That's why serving size matters as much as concentration.

Also check the detection limit. "Not detected" only means below what that lab can measure. A result of "<10ppb" on a 35g scoop means less than 0.35µg, which is useful. A result of "<100ppb" means less than 3.5µg, which doesn't tell you much.

Cantein's results

We sent a sample of the hemp protein in Cantein to Eurofins, which tested it by ICP mass spectrometry in September 2025. Unflavored Cantein is 100% this hemp protein, so a 35g scoop of unflavored is 35g of what was tested.

All four metals came in under every benchmark in the table above, including the strict Prop 65 level for lead. For context, lead in the products CR tested ranged from undetectable to 70.2ppb, and about 40% were above 14ppb.

What this doesn't tell you:

• It's one sample. Metals vary with soil and harvest, so one result isn't a guarantee for every bag. CR averaged two to four lots per product.
• Arsenic wasn't split by type. The test measured total arsenic, which includes organic forms that are much less toxic. Health limits are set for inorganic arsenic, so the comparison above assumes the worst case.
• Vanilla and chocolate weren't tested as finished products. They contain less hemp per scoop, but they add other ingredients, and cocoa can carry metals of its own.

Want the full Eurofins report? Email info@cantein.com and we'll send it.

How to choose a lower-lead protein powder

• Ask for per-lot heavy-metal results, not a general "tested" claim. Look for lead, cadmium, arsenic, and mercury, with units and detection limits.
• Convert to µg per serving using the formula above, and compare with 0.5µg for lead and 4.1µg for cadmium.
• Don't assume organic means low metals. USDA Organic rules cover how a crop is grown. They don't set limits for heavy metals already in the soil.
• Watch the serving size. A double scoop doubles the dose.
• Mix your protein sources. Eggs, tofu, beans, fish, and dairy if you eat it spread your exposure across different foods.
• Be more careful if you're pregnant or the powder is for a child. CR suggests these groups favor food over powders where possible.

FAQ

Does all protein powder have lead? Most contain at least a trace, because lead is in soil. In CR's 2025 tests, fewer products had undetectable lead than in its 2010 tests.

Is plant protein worse than whey for lead? In CR's tests, plant products averaged nine times more lead than dairy ones. All the plant products tested were pea-based, so the results don't tell you about hemp, rice, or soy specifically.

Is hemp protein high in lead? It depends on the soil and the harvest. Hemp tends to take up cadmium more than lead, so check both. Our sample tested at 6.28ppb lead, or 0.22µg per scoop.

Is chocolate protein powder higher in lead? CR found no meaningful difference between chocolate and vanilla this time, although cocoa has been a source of heavy metals in other testing.

Sources

• Consumer Reports. Protein powders and shakes contain high levels of lead, October 2025. consumerreports.org
• Consumer Reports. Heavy metals in protein supplements: methodology and test results, 2025. consumerreports.org (PDF)
• FDA. Lead in food and foodwares (interim reference levels). fda.gov
• Flannery BM, Middleton KB. Updated interim reference levels for dietary lead to support FDA's Closer to Zero action plan. Regulatory Toxicology and Pharmacology, 2022. pubmed.ncbi.nlm.nih.gov/35690180/
• OEHHA. Proposition 65 safe harbor levels: lead and cadmium. oehha.ca.gov (lead), oehha.ca.gov (cadmium)
• Linger P et al. Industrial hemp (Cannabis sativa L.) growing on heavy metal contaminated soil: fibre quality and phytoremediation potential. Industrial Crops and Products, 2002. doi.org/10.1016/S0926-6690(02)00005-5
• OEHHA. Proposition 65 safe harbor level: inorganic arsenic. oehha.ca.gov
• Eurofins Food Chemistry Testing Madison. Certificate of analysis 5085772-0, hemp protein heavy metals (ICP-MS), September 24, 2025. Full report available from info@cantein.com

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