Lead in Protein Powder: What the Tests Found and What to Do

Consumer Reports tested 23 popular protein powders and ready-to-drink shakes and reported that more than two-thirds delivered more lead in a single serving than its food safety experts consider acceptable in a whole day [1]. That finding is real, and it is worth acting on — but the number everyone repeats, "70% exceeded the level of concern," is not a toxicity threshold, and almost no coverage explains the arithmetic. Here is what the benchmarks actually mean, why plant-based powders test higher, and how to cut your exposure without giving up your shake.

What Consumer Reports tested — and what the numbers mean

CR anonymously bought samples of each product from online retailers, supermarkets and health food stores, covering two to four distinct manufacturing lots per product over three months, and tested for protein, lead, cadmium, inorganic arsenic and other elements. Results are lot averages, which CR notes may not mirror what is in a tub you buy today [1].

The headline findings:

• About 70% of the products contained more than 120% of CR's "level of concern" for lead, which CR sets at 0.5 micrograms (mcg) per day [1].
• Two plant-based powders were flagged as products to avoid: one mass gainer contained 7.7 mcg of lead per serving (about 1,570% of CR's level of concern) and one meal-replacement-style powder contained 6.3 mcg (about 1,290%) [1].
• Lead in the plant-based products averaged roughly nine times the level found in dairy-based products such as whey, and about twice the level in beef-based products. Even so, half the dairy products tested high enough that CR advised against daily use [1].
• Lead was the main problem, but not the only one. Three products exceeded CR's level of concern for cadmium or inorganic arsenic — including one plant powder with 9.2 mcg of cadmium per serving against a 4.1 mcg daily benchmark, and one whey-based mass gainer with 8.5 mcg of inorganic arsenic [1].
• Every product met or exceeded its label claim for protein, delivering 20 to 60 grams per serving [1].

A follow-up round published in January 2026 tested five reader-requested chocolate powders and told a different story: four came in below CR's 0.5 mcg level of concern, from 0.21 to 0.46 mcg of lead per serving, and the fifth landed just above at 0.53 mcg [2]. Same category, same lab, very different results — the most useful finding in the whole project. Low-lead protein powder is clearly manufacturable; it just is not guaranteed.

Bottom line: The spread between products is enormous — from not detectable to 7.7 mcg per serving. Which powder you choose matters far more than whether you use protein powder at all.

"Level of concern" vs. Prop 65 MADL vs. actual toxicity

This is where most coverage goes wrong. Three different numbers get treated as if they were the same kind of limit. They are not.

CR's level of concern (0.5 mcg/day). CR borrows California's Proposition 65 maximum allowable dose level (MADL) for lead and applies it to a single serving, assuming you have one serving a day [1]. CR is explicit that this is not a legal judgment: Prop 65 averages exposure over time and dietary frequency, while CR assumes daily use, so no Prop 65 conclusions can be drawn from its results, and the numbers are meant to rank products, not to mark the point where harm begins [1].

The Prop 65 MADL (0.5 mcg/day). California lists lead as a reproductive toxicant, and the MADL is a warning-label trigger, not a poisoning threshold. Under Prop 65, the "no observable effect level" is identified and then divided by 1,000 to build in a margin of safety; businesses must warn when exposures exceed that one-thousandth figure [3]. California's safe harbor table lists the oral MADL for lead as 0.5 mcg/day, alongside a separate cancer-based no significant risk level of 15 mcg/day [4].

The FDA's interim reference level (8.8 mcg/day for adults). The FDA derives its IRL from the CDC's blood lead reference value of 3.5 micrograms per deciliter, with a 10-fold safety factor built in, producing 2.2 mcg/day for children and 8.8 mcg/day for females of childbearing age [5]. The CDC value itself is a statistical screening marker — it identifies the roughly 2.5% of US children with the highest blood lead levels, not a level at which harm starts [6]. An FDA spokesperson told CR there is sufficient evidence to apply the 8.8 mcg/day benchmark to all adults [1].

The crucial difference: the FDA's number covers everything you eat and drink in a day, while CR's applies to one product [7].

So what does exceeding CR's level of concern actually mean? It means a product is in the higher-lead part of a category that has no federal limit at all — not that a serving will hurt you. CR says plainly that none of the products it tested contained enough lead to cause immediate harm, and that there is no reason to panic if you have been using one [1]. The supplement trade group Council for Responsible Nutrition pushed back harder, arguing CR's threshold "creates a misleading impression of risk" and that exceeding a self-imposed threshold is not the same as exceeding a government limit [1].

Both things can be true. There is no enforceable federal limit for lead in protein powder, the FDA does not review or test supplements before sale, and the FDA itself states that no safe level of lead exposure has been identified [1, 5]. In that vacuum a conservative screening number is a fair way to rank products — as long as you read it as a ranking, not a verdict.

Good to know: Lead is cumulative. CR notes that more than 90% of absorbed lead is stored in bone and can be released back into the blood during pregnancy, illness or older age, which is why a single blood test can under-represent long-term exposure [7]. That is the real argument for keeping avoidable exposure low, not any single shake.

Why plant proteins test higher — and what chocolate has to do with it

Plants take up what is in their soil, water and air, so crops carry trace lead from both natural geology and human activity such as industrial pollution and road dust [1]. Every plant-based powder in CR's main test used pea protein as a primary ingredient, and CR's tests could not separate how much contamination came from the peas themselves versus the way plant protein is concentrated [1].

That processing step is the part shoppers underrate. Turning dried peas into a high-protein powder means dehulling, milling, wet separation, acid coagulation and spray drying — and experts CR interviewed note that each step, depending on equipment, water and processing aids, is an opportunity to add contamination [1]. Concentration works against you arithmetically too: the metals stay while starch, fibre and water are stripped away. Dairy proteins start from milk, among the lowest-lead foods in FDA monitoring data, and go through fewer such steps [1, 7].

Sourcing matters too. Much of the pea protein used in US food production has historically been imported from China, and the FDA rarely audits foreign supplement makers [1]. One brand told CR it had moved its pea sourcing to North America and renamed the product, precisely because naturally occurring heavy metal levels reflect the soil the crop was grown in [1].

The chocolate question

Cocoa is a well-documented source of lead and cadmium in other product categories, so the assumption that chocolate flavours drive the protein powder results is reasonable. CR's data does not support it. Across the products tested, average lead concentration was 17.3 parts per billion in chocolate products and 15.4 ppb in vanilla ones — no meaningful difference [1, 7]. And in CR's January follow-up, which deliberately tested only chocolate powders, four of five came in under the level of concern [2].

Choosing vanilla is not a heavy-metal strategy. Choosing a brand that tests every lot is.

What about rice protein?

CR's line-up did not include a rice-protein powder, so the popular claim that rice-based powders are the worst offenders is not something these tests can settle. What is well established is that rice takes up inorganic arsenic more readily than most crops, which is why the FDA treats arsenic in rice and rice products as a priority and advises eating a variety of nutrient-dense foods across food groups to limit exposure from any single source [8]. Arsenic did show up in CR's testing — in a whey-based mass gainer, not a plant powder [1]. Treat ingredient type as a rough prior, not a guarantee.

How much is too much: serving size, frequency and your whole diet

Three numbers decide your actual exposure, and only one of them is printed in headlines.

1. Concentration (parts per billion) is not dose. Parts per billion measures how much lead is in the powder; micrograms per serving is what you swallow. The conversion is simple: ppb multiplied by serving size in kilograms. A 30-gram scoop at 15 ppb delivers about 0.45 mcg of lead; the same powder in a 60-gram double scoop delivers 0.9 mcg. For context, seven of the supplements CR tested had lead concentrations above 20 ppb and three ran from 60 to 70 ppb, while dairy products in the FDA's broader food monitoring averaged from not detectable to 2.1 ppb [7].

2. Serving size amplifies, but does not determine. Mass gainers in CR's test had serving sizes from roughly 190 to 360 grams, which is why some of them topped the chart. But serving size was not decisive: the product with the single largest serving (357 grams) had no detectable lead at all [7].

3. Frequency is the lever you control. CR's per-product advice is just division. If one serving equals 140% of a 0.5 mcg daily budget, then seven days' worth of budget divided by 1.4 is five servings a week — which is exactly the kind of weekly limit CR publishes for mid-range products [1]. A product at 500% of the level of concern works out to roughly one and a half servings a week; a product at 50% leaves room for two a day.

Then there is the rest of your diet. FDA scientists have estimated that the average American adult takes in up to 5.3 mcg of lead per day from food [1], which is why the agency monitors contaminants across hundreds of foods in its Total Diet Study rather than one product at a time [9]. Against an 8.8 mcg/day adult interim reference level, a 0.2 to 0.5 mcg shake is a rounding error; a 7.7 mcg mass gainer taken daily is not [1, 7]. Most tested products add a little to an existing load; a handful add more than everything else you eat. If you are unsure how much powder you need in the first place, start with our guide to daily protein targets.

Safety note: If you are pregnant, trying to conceive, breastfeeding, or buying for a child or teenager, the margins are tighter — the FDA's children's benchmark is 2.2 mcg/day for the entire diet [5]. CR's advice for these groups is to favour food sources or dairy-based powders with confirmable low lead levels [7]. If you have been using a high-lead product daily for years, that is a conversation to have with your clinician, who can judge whether testing makes sense for you.

How to vet a protein powder for heavy metals

The supplement aisle gives you three kinds of evidence, and they are not equally good.

Certificates of analysis, and the batch question

A certificate of analysis (COA) is a lab report for a specific lot. The question to ask is whose lot. Some companies test only incoming ingredients, or rely on supplier COAs, or spot-check occasionally — all of which technically satisfy federal requirements [2]. Others test every finished lot. One brand in CR's follow-up said it ran 162 heavy-metal tests on a single chocolate powder over 12 months and rejects ingredients that miss its internal limits; another publishes heavy-metal results for a recent lot of each flavour and names its suppliers and manufacturing sites [2].

Transparency is still rare. Of the 23 brands in CR's original test, only two said they publish results on their websites, and two more said they would send results on request [7].

What to look for:

• A COA that names the specific lot number on your tub, not a generic "sample" report.
• Lead, cadmium, arsenic and mercury reported with a stated limit of detection. "Non-detect" is meaningless if the method cannot see below, say, 50 ppb — CR noted that some companies claiming non-detectable lead were using less sensitive methods than its triple-quadrupole ICP-MS [7].
• Results expressed per serving, or enough information (ppb plus serving size) for you to do the conversion yourself.

Third-party certifications: useful, but read the fine print

NSF certification to NSF/ANSI 173 confirms label accuracy and that a product contains no unsafe levels of contaminants such as heavy metals, pesticides and herbicides; NSF Certified for Sport adds banned-substance screening on top [10]. USP Verified similarly checks identity and potency, screens for harmful levels of specified contaminants including lead, and audits manufacturing against FDA good manufacturing practices [11].

These marks are a meaningful floor — but a floor. The lead limit a product must meet for NSF certification is 10 mcg per day, twenty times CR's level of concern [1]. A certified product can therefore be both legitimately certified and higher in lead than you would choose. Certification tells you a third party checked; the COA tells you what they found. Our explainer on NSF, Informed Sport and USP covers what each seal does and does not promise.

Prop 65 warnings, and the loophole

Products sold in California that expose consumers above the MADL must carry a Prop 65 warning [1], so a warning label on a protein powder is a signal worth heeding. But absence of a warning is weaker evidence than it looks: one brand told CR it operates under Prop 65 consent decrees — legally binding settlements that may allow a company to work to higher thresholds — after paying roughly $336,000 to resolve 2013 and 2018 allegations about heavy metals, with no admission of wrongdoing [1].

Red flags on the label and the listing

• "Lab tested" or "third-party tested" with no document, lot number or lab named.
• A brand that will not answer a direct email asking for the COA for your lot.
• "All natural" used as a safety cue. It is not a contaminant standard, and NSF flags unregulated catch phrases as a reason to look harder at a label [10].
• Giant serving sizes. Mass gainers multiply whatever is in the powder by six scoops.

If you buy through social commerce, the vetting problem is harder, not easier — our guide to vetting viral supplements and reading a Supplement Facts label both apply here.

Lower-exposure swaps and a practical checklist

None of this requires giving up protein supplements. It requires treating them like any other processed food: know the source, vary it, and do not make one product the backbone of your diet.

• Default to dairy-based protein for daily use. Across CR's testing, dairy proteins averaged roughly a ninth of the lead found in plant proteins, and the lowest-lead powders in the follow-up round were whey-based [1, 2]. If you tolerate dairy, whey or casein is the lower-exposure default — see whey isolate vs. concentrate for choosing among them.
• If you need plant protein, demand documentation. Plant powders are not uniformly bad: one pea-based powder in CR's follow-up came in at 93% of the level of concern, below the daily threshold [2]. Pick the ones that publish lot-level results.
• Rotate your sources. Alternating two or three powders from different protein sources keeps one contaminated lot from dominating your exposure. The FDA makes the same argument for food: variety limits exposure to any single contaminant source [8].
• Shrink the dose before you drop the habit. Half a scoop halves the lead. Most people do not need 50 grams of protein from a shake on top of meals.
• Replace some shakes with food. Greek yogurt, milk, eggs, cottage cheese, tofu, fish and poultry supply protein without a concentration step. CR's own advice is to make shakes with high-protein foods where you can [7].
• Skip the daily mass gainer. The largest servings carry the largest doses, and the two products CR told readers to avoid outright were both very large-serving plant formulas [1].
• Re-check your product annually. Formulations move: one brand changed pea sourcing and renamed its product, and another discontinued the exact items CR tested [1]. A result from a 2024-purchased lot does not describe a 2026 tub.

Pro tip: Email the brand and ask one question: "Do you test every finished lot for heavy metals, and can you send the COA for lot number X?" The answer — fast and specific, vague, or silent — tells you most of what you need to know. You can start from our protein powder category page and shortlist brands that publish results.

What has changed since the report

The FDA told CR it has reviewed the findings and initiated targeted inspections and sampling focused on the issue, while still having no enforceable lead limits for supplements; CR's petition for federal limits had gathered more than 43,000 signatures by January 2026 [2]. Meanwhile the aggregator posts ranking "all tested brands" keep circulating without noting that several tested formulas have since been reformulated or discontinued [1].

The bottom line

Lead in protein powder is a real, measurable problem, and it is also a solvable one. CR's testing found most products exceeded a deliberately conservative 0.5 mcg/day screening threshold borrowed from California's Prop 65 — a warning-label trigger set at one-thousandth of a no-effect level, not a toxicity limit — while the FDA's whole-diet benchmark for adults is 8.8 mcg/day [1, 3, 5]. For the great majority of tested products, a daily serving adds a fraction of a microgram to an existing dietary load of around 5 micrograms. For a small number, mostly very large-serving plant-based formulas, it adds more than everything else you eat.

The practical response is not fear; it is selection and moderation. Choose dairy-based powder for daily use unless you have a reason not to, buy from brands that test every lot and publish the results, rotate products, keep servings modest, and get more of your protein from food. If you are pregnant, nursing, or buying for a child, be stricter still and bring the question to your clinician.