Yes, many protein powders contain detectable heavy metals. Lead was the main heavy metal of concern in Consumer Reports' testing, where about 70 percent of the 23 products in CR's original tests contained over 120 percent of CR's lead level of concern. CR later tested five more powders and found low lead. A 2020 risk study that modeled one to three servings a day found no increased non-cancer health risk in nearly all scenarios, so the useful question is which product you buy, how much you use, and whether its maker publishes recent test results for that exact product.
What did Consumer Reports find in protein powder?
As of October 2026, Consumer Reports' protein powder investigation is the best-known test in this area. CR bought two to four lots of each product over three months, from online retailers and from stores in New York state. It tested samples for total protein, arsenic, cadmium, lead and other elements. Because it reports averages across those lots, its numbers may not match what is on shelves today.
Lead was the main heavy metal that showed up. CR measures lead against a level of concern of 0.5 micrograms per day, which comes from California's Proposition 65 limit. Cadmium and inorganic arsenic also appeared in some products, and three products exceeded CR's level of concern for cadmium or arsenic.
These are the products CR named, with its own per-serving figures:
| Product (as CR named it) | What CR found, per serving |
|---|---|
| Naked Nutrition Mass Gainer | Lead of 7.7 micrograms, about 1,570% of CR's level of concern. CR's experts advise against consuming it. |
| Huel Black Edition | Lead of 6.3 micrograms, about 1,290% of CR's level. Cadmium of 9.2 micrograms, more than double the 4.1-microgram daily level CR cites. CR's experts advise against consuming it. |
| Garden of Life Sport Organic Plant-Based Protein | Lead between 400% and 600% of CR's level. CR's Akinleye says to limit it to once a week. |
| Momentous 100% Plant Protein | Lead between 400% and 600% of CR's level. Same once-a-week limit. |
| MuscleMeds Carnivor Mass | Lead above 200% of CR's level. It is the only non-plant-based powder with lead that high. |
| Vega Premium Sport | Cadmium enough that one serving would put you just over CR's level. |
| Optimum Nutrition Serious Mass (whey) | Inorganic arsenic of 8.5 micrograms per serving, twice the daily amount CR's scientists consider safe. |
Read these against the maker responses. Garden of Life US and Orgain say their products are safe for daily use despite CR's recommended limits. Momentous says the products CR tested have been discontinued. CR reports that Vega renamed the powder it tested Vega Protein + Recovery and now sources its pea protein from North America instead of China. Naked Nutrition says it is “in the process of obtaining” NSF certification. Each of these is a maker's own statement, and a product's test results may have changed since CR bought it.
Do these levels mean the protein powder is dangerous?
The studies use different yardsticks, which is why they seem to disagree. CR compares each product to its 0.5-microgram lead level. Sana Mujahid, PhD, who oversees food safety research at CR, says that value is used “because it is the most protective lead standard available.”
The 2020 heavy metal risk assessment in Toxicology Reports asks a different question: does typical intake raise health risk? Its authors used earlier CR data on 15 products and Clean Label Project data on 133 products. Modeling one or three servings a day, they found a hazard index below 1 for arsenic, cadmium and mercury in nearly all scenarios, which means no increased non-cancer health risk under their assumptions. The exception was 3 servings a day of one Clean Label Project product with very high cadmium. Lead was assessed separately through modeled blood lead levels, which stayed below the CDC guidance value of 5 μg/dL. Only arsenic had a cancer estimate in their model, and they found no increased cancer risk from it at the intake they modeled.
The authors also state limits. The authors are from Cardno ChemRisk, a consulting firm, and the paper declares no competing financial interests.
Harvard Health's protein powder article takes a broader view. It notes that protein powder is a dietary supplement, that the FDA leaves safety and labeling to manufacturers, and that there is limited data on the long-term effects of high protein intake from supplements.
Which protein powders have low heavy metals?
No protein powder is shown to be free of heavy metals, and no single brand is the right choice for everyone. The pattern that shows up most in these studies favors whey. The Clean Label Project reports that whey-based powders generally showed much lower contaminant levels. Texas Health, citing the same project, says plant-based powders carried three times more lead than whey-based ones. The 2020 study also reports that all five of the top products with the lowest heavy metal content in the Clean Label Project data were labeled “Pure,” “Pro” or “100%” whey. The authors suggest isolated whey may contain the least contamination, though that is their inference.
Whey is not automatically low. CR's test of Optimum Nutrition's Serious Mass whey found 8.5 micrograms of inorganic arsenic per serving. The 2020 study found that weight-gainer products had the highest modeled risk, and that they contained plant-derived protein sources as well as whey. For background on whey itself, see our whey protein guide.
CR also tested five more powders after readers asked, and its follow-up article is headlined Consumer Reports' follow-up on five more powders, with the line “All Five Had Low Levels of Lead.” Plant-based powders are the group most often flagged, because plants absorb metals from soil. Organic is not a shortcut either. Texas Health reports that organic powders in the Clean Label Project data contained, on average, three times more lead than non-organic ones.
How can I tell if my protein powder contains lead?
Harvard Health notes there is no way to know whether a protein powder contains what its maker claims, because the FDA leaves safety checks to manufacturers. The most useful check is a test report for the product and lot you are buying. Texas Health describes a certificate of analysis (COA) as a document from an independent testing laboratory that shows which heavy metals were found and at what levels. Ask the brand for the COA for your lot.
Use these checks when you read a label or a report:
| What to look for | What it tells you |
|---|---|
| NSF Certified for Sport | CR reports that NSF certification requires limits of 10 micrograms per day for lead and inorganic arsenic, and 4.1 micrograms per day for cadmium. |
| Clean Label Project certification | Texas Health lists this as a sign of third-party testing, along with NSF. |
| Certificate of analysis (COA) | Lab results for heavy metals, with levels. Compare the per-serving figures with CR's 0.5-microgram lead level of concern, not only the NSF limits above. |
| Lot number and test date | Texas Health notes that formulations change, so a report from an older batch may not match what you buy. |
What is the Clean Label Project study, and how do the studies compare?
The Clean Label Project's protein study is a nonprofit report that many news stories cite. It says it contracted Ellipse Analytics to test heavy metals by ICP-MS. Sources give different counts for it. Texas Health describes 160 products from 70 top-selling brands in a 2024–2025 category report, while Harvard Health describes 134 products screened for 130 toxins in 2025. Check the report itself for the count. The table compares the three main studies.
| Study | What it tested | What it found |
|---|---|---|
| Consumer Reports investigation | 23 products in the original tests, two to four lots each, bought over three months | About 70% of the original 23 over 120% of CR's lead level of concern; cadmium and arsenic in some products; five later powders had low lead |
| Clean Label Project protein study | Top-selling products, as described in the report | 47% exceeded federal or state regulatory limits; 21% of products tested over twice the Prop 65 level for lead |
| 2020 risk assessment (Toxicology Reports) | Modeled CR's earlier 15 products and Clean Label Project's 133 | Hazard index for arsenic, cadmium and mercury below 1 in nearly all scenarios (exception: 3 servings a day of one product with very high cadmium); modeled blood lead below 5 μg/dL |
The Clean Label Project's 47% figure is a share of products, not a measure of how far each one exceeded a limit. Read the product-level numbers before you judge a brand.
What are the signs of heavy metals in the body?
Texas Health says short-term exposure to trace amounts is unlikely to cause immediate symptoms. The concern is consistent, long-term consumption. The table lists the effects the sources link to each metal.
| Metal | Effects linked in the sources |
|---|---|
| Lead | Impaired brain function, lower energy and heart health effects, according to CDC and EPA as cited by Texas Health. Long-term exposure has been linked to high blood pressure, kidney damage and reproductive issues. |
| Cadmium | Kidney function and bone health effects, and a link to certain cancers, as described by Texas Health. |
| Arsenic | Chronic exposure is associated with skin lesions and carcinogenic effects. The International Agency for Research on Cancer classifies inorganic arsenic as carcinogenic to humans, as the 2020 study reports. |
| Mercury | Sufficient exposure can cause neurological, motor, kidney, cardiovascular, immune and reproductive dysfunction, per the 2020 study. |
These are effects linked to high or long-term exposure, not a checklist you can use on yourself. If you notice symptoms or have concerns about your levels, see a clinician.
Can you flush heavy metals out of your body, and can the damage be undone?
This page does not cover methods to flush or pull metals out of the body, and it does not suggest any product for that. The studies above measure how much metal you take in from food and supplements. Whether effects of lead or cadmium can be undone depends on your own history and exposure, so put that question to a clinician who knows you.
How do I test myself for heavy metals?
Product tests check the powder, not you. The 2020 study expressed lead risk as modeled blood lead levels and compared them with a CDC guidance value of 5 μg/dL. Ask a clinician whether any test is appropriate for you, especially if you use protein powder daily or are a parent of a teen who does.
Which foods are highest in heavy metals?
The 2020 study describes arsenic, cadmium, lead and mercury as food-chain contaminants. Plants take up metals from air, water and soil, and those metals can remain after processing. The authors suggest plant and milk ingredients may be the main sources in protein powder, and that contaminated milk is a likely contributor to heavy metals in whey, although they say a direct link has not been established.
Chocolate is a special case. CR says earlier tests by CR and others identified chocolate as a notable source of heavy metal contamination. Its own protein powder test found no meaningful difference between the average lead in vanilla and chocolate products. Texas Health, citing the Clean Label Project, says chocolate-flavored powders contained up to four times more lead than vanilla. CR has also reported on lead and cadmium in dark chocolate separately.
Who should be most careful with protein powder?
| Concern | What the sources say |
|---|---|
| Regular, daily use | Texas Health says daily use of a powder with elevated heavy metal levels increases cumulative exposure over time. CR's Akinleye suggests regular users consider reducing consumption. |
| Teens and children | Texas Health says lead is especially harmful to the developing brain and suggests whole-food protein first. It advises checking with a pediatrician before starting a supplement. |
| Dairy allergy or lactose trouble | Harvard Health says milk-based powders can cause digestive discomfort in these people. |
| Added sugar and calories | Harvard Health says some powders contain up to 23 grams of added sugar per scoop, and some mixed with milk exceed 1,200 calories. It cites the American Heart Association limit of 24 grams of added sugar a day for women and 36 grams for men. |
| Long-term high protein intake | Harvard Health says there is limited data on the long-term effects of high protein intake from supplements. |
Do I need protein powder at all?
Harvard Health gives the Recommended Dietary Allowance for protein as 46 grams a day for women and 56 grams for men. It notes that most people can get plenty from ordinary foods, such as an egg (6 grams), 6 ounces of plain Greek yogurt (18 grams), or 2 ounces of cooked chicken (14 grams). Athletes and people with health issues should discuss their needs with their medical team. Texas Health says most adults can meet their daily protein needs through diet alone. If you want to see how protein powder fits a training goal, read do you need protein powder to build muscle.
What is still unknown about heavy metals in protein powder?
Several things are not settled yet. Test results are snapshots of specific lots, and formulations change. The long-term effects of high protein intake from supplements have limited data behind them. As of October 2026, CR reports that the FDA has not set action levels for lead in protein powders or shakes. CR also says the FDA told it that it monitors contaminants through its toxic element compliance program, special surveys and a cooperative agreement with states. The FDA said it would review CR's findings.
For more on contaminants beyond lead, see our guide to protein supplement contaminants.
Before you buy
- Ask the brand for the certificate of analysis for the exact lot you are buying, with heavy metal figures per serving.
- Look for NSF Certified for Sport or Clean Label Project certification on the label.
- Compare per-serving lead, cadmium and arsenic with CR's levels of concern, not only with the NSF limits. CR describes NSF certification limits as 10 micrograms per day for lead and inorganic arsenic, and 4.1 micrograms per day for cadmium. The NSF lead limit is about 20 times CR's 0.5-microgram level of concern, so meeting NSF's limit is not the same as meeting CR's level.
- Check the test date. Formulations and sourcing change, as Texas Health and CR both note.
- If you use protein powder daily, or you are a parent of a teen who does, ask a clinician whether you should cut back or test.
By the Gym Floor Guide Editorial Team
This article is for general information purposes only and does not constitute medical advice. Consult your doctor or qualified healthcare provider before making changes to your health routine.