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Greens powders: what the research shows

Greens powder tin and green drink

A scoop of greens powder promises the nutritional weight of several servings of vegetables in one glass. It can supply some real fiber and plant compounds, but recent independent testing raises a separate concern that has nothing to do with whether the powder "works."

Independent lab testing of 37 best-selling spirulina and greens powder products, validated through third-party labs Eurofins and Alkemist Labs, found lead contamination in a large share of them.[1]

Spirulina products exceeding California's lead limit8 of 24
Organic spirulina products exceeding the limit6 of 14
Mixed greens powders exceeding the limit10 of an unspecified total
Organic mixed greens exceeding the limit8 of 13

Some products exceeded California's Prop 65 lead threshold by as little as 1.4 times the limit; others ran as high as 9.2 times over. The "organic" label didn't protect against this. Organic spirulina and organic mixed greens both failed at similar or higher rates than conventional products, since lead contamination usually traces back to the soil or water where the plants grew, not to farming method.

Separate from contamination, the fiber and nutrient content in most greens powders is clearly smaller than a plate of real vegetables. A single scoop typically supplies 1 to 2 grams of fiber, compared with 4 to 5 grams in a cup of cooked spinach or broccoli. The powder isn't nutritionally equivalent to the vegetables it pictures on the label.

Look for third-party heavy metal testing results, not just a "third-party tested" claim with no report attached.
Check for an NSF/ANSI 173 certification, which caps lead at 10 micrograms per daily dose.
Don't assume "organic" means lower heavy metal risk; the testing above found no consistent advantage.
Treat the powder as a supplement to vegetables, not a replacement for them.

What to do with this

If you already use a greens powder daily, check the brand against published third-party heavy metal results before your next purchase. Several consumer testing groups publish these lists and update them as new products are tested. Daily long-term use of a contaminated product matters more than an occasional scoop, since lead exposure accumulates in the body over time. If you can't confirm testing, rotate brands rather than committing to one daily, and don't treat any powder as a substitute for eating actual vegetables. The same due-diligence habit applies to other trendy supplements, including charcoal supplements.

  1. "Get the Lead Out: Testing Reveals Heavy Metals in Greens Powders and Spirulina Products." Nutraceuticals World, citing Cyanotech testing with Eurofins and Alkemist Labs validation. nutraceuticalsworld.com

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