To help answer our most pressing protein questions, we interviewed four registered dietitians. Photograph: Organic Media/Getty Images View image in fullscreen To help answer our most pressing protein questions, we interviewed four registered dietitians. Photograph: Organic Media/Getty Images Guardian journalism is independent. We earn a commission if you buy something through an affiliate link. Learn more .
If you’re wondering whether ‘organic’ really matters or if there’s such a thing as too much protein, this is for you
The 10 best (and worst) whey protein powders – tested
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Lauren Gould Mon 12 Oct 2026 16.15 CEST Share Prefer the Guardian on Google If our protein powder taste test taught us anything, it’s that these supplements are confusing.
While plant and whey powders are both popular, we opted for whey, given its surging prices and popularity (and the former’s higher risk of lead ).
What started as a simple mission to find the best-tasting powders soon led us down a rabbit hole, asking, “What does NSF certification mean?” and “Is organic whey actually better?”
To further muddy the waters, the US Food and Drug Administration doesn’t test the safety of protein powders, including whether they contain heavy metals such as lead . They also don’t verify marketing claims promising improved muscle growth or recovery.
So to help answer our most pressing protein questions, we interviewed four registered dietitians.
Read the story: The 10 best (and worst) whey protein powders – tested
Nancy Rodriguez , RD, FACSM and professor of nutritional sciences at the University of Connecticut
Jamie Na deau , RDN with over a decade of experience
Nyree Dardarian , RDN, LDN and assistant clinical professor at Drexel University
Kacie Vavrek , RD at the Ohio State University’s Wexner medical center
Responses were edited for clarity and length.
Lauren Gould: What ingredients should we avoid?
Kacie Vavrek: While there’s no single ingredient everyone needs to avoid, some people may want to limit added sugars, excessive sugar alcohols (such as erythritol or sorbitol), or artificial sweeteners if they cause digestive issues.
Nyree Dardarian: Whenever I see the words “proprietary blend”, I roll my eyes a little. Just tell me what’s in it. I’m also not a fan of products with more than 100% of the recommended daily allowance for a bunch of vitamins and minerals unless you actually need them.
Jamie Na deau: There is no reason to avoid trace minerals in protein powders in normal amounts, but most people do not need their protein powder to be supplemented with trace minerals.
LG: You recommend third-party certified protein powders. Which certifications are best?
JN: Look for certificationssuch as NSF Certified for Sport , Informed Sport or USP Verified . Those programs help confirm that the product contains what the label claims and is tested for contaminants. Sports certifications such as NSF Certified for Sport also screen for banned substances.
ND: Third-party testing is a good sign, but it doesn’t make a product bulletproof.
LG: Is organic whey better than regular?
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ND: Don’t automatically assume organic means healthier or better.
JN: Organic whey is a personal preference, but not necessary for a protein powder to be nutritious. I would prioritize independent third…