Is heavy metals in protein powder safe during pregnancy?

What does the evidence say about heavy metals in protein powder during pregnancy?

1. A 2025 laboratory analysis of 22 commercial protein powders, including whey, vegan, and beef-based formulas, did not detect lead, cadmium, arsenic, or mercury above regulatory limits, though vegan powders ran higher in aluminum and manganese, and the researchers cautioned that supplement manufacturing relies on voluntary compliance rather than mandatory heavy-metal testing. 1
2. A separate published risk assessment of protein powder supplements found some level of heavy metal in every product tested, but modeled exposure for a standard adult serving stayed under the hazard threshold the researchers used, with estimated blood lead levels below the reference guidance value they cited, though plant-based and weight-gainer formulas carried higher metal levels than whey. 2
3. MotherToBaby lists dietary supplements among everyday sources of lead exposure alongside soil, water, and old paint, and documents that high lead exposure during pregnancy has been linked to miscarriage, low birth weight, preterm delivery, preeclampsia, and effects on the developing fetal brain. 3
4. A cohort study of more than 5,200 pregnant women found that maternal cadmium levels in both early and late pregnancy were significantly linked to lower infant birth weight, with the researchers noting the association held even at low levels of exposure. 4
5. An NIH-funded study following more than 1,400 mother-child pairs found that children born to mothers with high blood lead levels during pregnancy were over four times as likely to be overweight or obese by around age 8, and adequate maternal folate appeared to lower that risk. 5

Is heavy metals in protein powder safe in each trimester?

• First trimester. Heavy metals can cross the placenta from the earliest weeks, and the cohort research below found maternal cadmium levels in early pregnancy already linked to lower birth weight. If nausea makes a shake one of the few things you can keep down, that is a reasonable stopgap, but pick a single-ingredient, third-party tested powder rather than a blended pre-workout or weight-gainer formula, since those trended higher in heavy-metal testing.
• Second trimester. Appetite typically picks up in the second trimester, which is when many people lean on a daily shake to hit protein goals. The same testing that found protein powder heavy-metal levels usually falling under modeled safety thresholds also found that industry testing is voluntary, so consistency matters more than any single product's marketing claim. Rotating brands or keeping intake moderate is more useful than relying on one formula every day.
• Third trimester. Late pregnancy is when the cohort research below also linked maternal cadmium levels to birth weight, so the same caution applies through the third trimester, not just early on. Protein needs rise some as the baby grows, but food should stay the main source, with a tested powder as backup rather than a daily multi-scoop habit.