Shoppers still want protein. In 2026 the category's exposure moved from whether people will buy to whether a brand can prove what's in the tub.
Nothing in the protein data points to a demand problem. SPINS says protein powders and shakes keep growing at high single to low double digits, year after year. Glanbia’s Optimum Nutrition grew 25% like-for-like in the first half. “Protein powder” ranks among the top 40 searches on Amazon US by third-party estimates, and seven in ten Americans told IFIC they are trying to consume protein. GLP-1 users, advised to protect muscle while eating less, are adding to the queue.
The exposure is somewhere else. Since April, at least ten California Prop 65 notices alleging lead in protein powders and shakes have named Amazon itself, nine of them alongside specific ASINs. Texas opened an industry-wide investigation in June. A July class action against Costco alleges excess lead in Orgain powders (Orgain says they are safe to consume) — powders that third-party estimates rank near the top of Amazon’s protein search. And whey has more than tripled in price, which is pushing brands toward the proteins with the worst testing record. Protein demand isn’t the risk anymore. Proof is.
Demand. SPINS data published in Nutritional Outlook in February put standalone whey protein at $687 million in the multi-outlet channel for the year to November 30, 2025, up 14.4%; animal protein overall reached $1.5 billion, up 27.3%. Euromonitor ties a $3 trillion global protein economy partly to GLP-1 users, and warned in July that “brands that rely on protein claims alone will find it harder to hold attention as scrutiny rises.”
The testing record. Clean Label Project’s January 2025 report on 160 products from 70 brands found 47% exceeded Prop 65 thresholds for toxic metals, with plant-based powders carrying roughly three times the lead of whey and chocolate roughly four times vanilla. Industry groups criticized the report as not peer-reviewed. Consumer Reports followed in October 2025: of 23 powders and shakes, more than two-thirds had more lead in a serving than CR considers safe for a full day — a 0.5 µg benchmark aligned with Prop 65, not a federal limit. Plant-based powders averaged nine times the lead of dairy. There is a counterweight worth stating: when CR tested five more chocolate powders in January, all five came back low enough for daily use.
The enforcement timeline. Reading California’s Prop 65 notice database, we count at least ten lead notices on protein powders and shakes between April 17 and August 21 that name Amazon.com Services LLC — nine of them citing specific ASINs, and eight dated after June 29, one of which amends an April notice. At least four of the ten are plant-based products; three are chocolate; one names a Glanbia-made product. Two noticers filed nine of the ten. That count is a floor, not a census, and every notice is an allegation, not a finding.
| Date | Event |
|---|---|
| April 17 | Earliest Amazon-named protein notices we found |
| May 14 | California SB 1033 — lot-level heavy-metal testing with disclosure on online product pages — held in committee |
| June 8 | Texas Attorney General opens industry-wide investigation of protein powder makers under the state’s consumer-protection law |
| June 29 – August 21 | Nine more Amazon-named protein notices (one amends an April 17 notice) |
| July | Federal suit against Costco over Orgain powders; Orgain says its products are safe to consume |
The cost. USDA’s Dairy Market News described concentrated whey protein (WPC80) in June as trading at “upper $12s to $13” a pound, with “no new sales because product was unavailable.” By late August it was $11.50–12.85, with demand “stable to softer,” while USDA called the lower-protein WPC34 market “extremely tight.” Ever.Ag data reported by the AP put WPC80 up 250% year over year. One snack brand’s whey went from $7 to $12 a pound, according to Fortune; another protein brand was cut off by a distributor and raised prices about 10%.
There is no federal number. A federal health spokesperson told reporters last year that “there is not an action level for lead in protein powders.” FDA’s non-binding Closer to Zero lead action levels cover processed food for children under two. In the absence of a federal standard, the working benchmark is Prop 65’s 0.5 µg a day — the number Consumer Reports uses, the number noticers enforce, and the number industry groups dispute.
The listing is now the unit of liability. Prop 65 notices cite ASINs and name the marketplace. California’s stalled SB 1033 would have required a heavy-metal testing statement on the online product detail page itself. Texas’s investigation, under its deceptive trade practices law, frames the question as disclosure. Every one of those mechanisms points at the product page.
The cost squeeze pushes toward the worst-testing proteins. At $12–13 a pound for whey concentrate, brands reformulate, switch suppliers and blend. NOW Foods raised whey prices and is looking at milk protein concentrate. Plant protein and blends move up the mix — and plant protein is where both major testing rounds found the most lead. The rational cost decision and the rational compliance decision are pulling in opposite directions.
Amazon’s own layer. Testing firm SGS lists bodybuilding and sports nutrition among the categories Amazon treats as high-risk, and says verification for them typically includes heavy-metal screening. We found no public Amazon limits.
They publish the proof. Momentous posts per-batch heavy-metal results on its product pages alongside certificates of analysis, and carries NSF Certified for Sport. Ritual publishes recent-batch heavy-metal results for its protein on a traceability certificate. Both can point to published data when a test headline lands.
They answer with context, not silence. When CR named their products, Naked responded on serving size and per-gram comparisons, and Huel published a FAQ calling Prop 65 an “exceptionally conservative threshold.” Weaker than publishing data — but a stated position beats an unanswered headline.
They secured supply rather than reformulating in a hurry. Glanbia grew volume through the squeeze and is adding whey isolate capacity in New Mexico for 2027. Securing supply avoids reaching for an untested substitute.
If you sell protein on Amazon, the brands that win the next twelve months will not be the ones with the cheapest gram of protein. They will be the ones that can show their numbers.
Get a lot-level heavy-metal panel for every SKU and flavor. Lead, cadmium, arsenic and mercury, expressed per serving in micrograms. Know where each SKU sits against the 0.5 µg Prop 65 benchmark, USP’s 5 µg-a-day permitted daily exposure for lead and FDA’s interim reference levels. Chocolate and plant-based SKUs first.
Test before you switch. If whey costs are forcing a reformulation or a new supplier, test the new protein source for heavy metals before launch — not after a notice arrives.
Put proof where the shopper decides. An A+ module or image stating what was tested, by whom, for which lot. Do not write “lead-free,” “zero heavy metals” or “safe.” Write “tested for lead, cadmium, arsenic and mercury — results by lot.”
Decide your Prop 65 posture with counsel. Either a warning for California shipments or a test record you can defend. Expect notices on your ASINs to reach you through Amazon.
Watch Texas and California. The Texas probe has not named companies yet. SB 1033’s product-page disclosure model is the likely template if it returns.
If you want a compliance read on your protein listings, Verid8 checks titles, bullets and images against Amazon’s supplement rules — start with a free listing scan. For a catalog-wide review of claims, certificates and margin, order an audit.
Keep reading: When you actually need a Prop 65 warning · Amazon’s TIC verification, explained · Creatine’s second act
Market Analyses are published the first Tuesday of every month. Figures as of September 1, 2026. Sources: SPINS via Nutritional Outlook, IFIC, Euromonitor, Glanbia, Fortune, SGS, ASINsight estimates, Clean Label Project, Consumer Reports, FDA, USDA Dairy Market News, Ever.Ag via AP, California OAG Prop 65 notices, the Texas Attorney General and court reporting. Prop 65 notices and lawsuits are allegations. This report is market analysis, not legal advice. The next report looks at gummies across the supplement aisle.
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