In October 2025, Consumer Reports tested 23 protein powders and shakes for lead content and found that a majority exceeded California's safety threshold — some by a wide margin. The coverage that followed threw around phrases like "10 times the limit" without always explaining what that limit actually is, or how a reader could check their own product against it.
Prop 65 MADL lead calculator: what the number actually means
California's Proposition 65 sets a Maximum Allowable Dose Level (MADL) for lead at 0.5 micrograms per day for reproductive toxicity — a figure set in 1989 and upheld in more recent California court rulings. It's the threshold above which a product sold in California legally requires a Prop 65 warning label. Importantly, the MADL is a regulatory disclosure threshold, not a line marking acute poisoning risk — exceeding it triggers a warning requirement, not a medical emergency.
How much lead in protein powder is safe?
That's not a question this article — or any calculator — can answer with a single number, because "safe" depends on your total lead exposure from all sources (diet, environment, water), not just one product. What a Prop 65 comparison can tell you is how a specific product's measured lead content compares to California's regulatory reference point, which is useful context even if it isn't a complete safety verdict.
Protein powder lead Prop 65 limit: checking your own product
If you have a lead content figure from a lab report, product label, or recall notice — usually expressed in micrograms per serving — you can compare it directly against the 0.5 mcg/day MADL. A product with 2 mcg of lead per serving, taken once daily, delivers 4 times the MADL in a single serving. A product with 0.25 mcg per serving sits at half the MADL at one serving a day, and would need two servings to reach it.
Where the Consumer Reports findings fit in
Consumer Reports' October 2025 investigation is what put this issue on people's radar, and it's the reason this calculator exists — but this tool intentionally doesn't repeat specific brand-by-brand results here, since that data can change as products are reformulated or retested. If you want to check a specific product, look for its own lab results, a recall notice, or the original Consumer Reports report itself.
Try the Protein Powder Lead Exposure Checker →
Sources: Consumer Reports, "Protein Powders and Shakes Contain High Levels of Lead" (2025-10); OEHHA (California Office of Environmental Health Hazard Assessment), Proposition 65 No Significant Risk Levels and Maximum Allowable Dose Levels; Mintz, "Prop 65: GET THE LEAD OUT!" (2018, summarizing the 1989 MADL and subsequent court rulings).
