Kirkland Signature
USP Verified on about two dozen products · Budget
Costco's own label, made by third-party contract manufacturers. It is one of only 16 brands in USP's Verified product database, with roughly two dozen verified items including Daily Multi, Calcium 600 mg with D3, Fish Oil 1000 mg and CoQ10 300 mg. That verification is per-product, not brand-wide — Costco's own vitamin guide says the mark appears on 'many' of its products, which matches the listing. No Kirkland Signature supplement appears in NSF's dietary-supplement database or in NSF Certified for Sport.
Quality programmes this brand reports
As published by the brand. Where the certifier keeps a public registry — NSF, USP, Informed Sport — look up the specific product there: a company-wide claim is not a batch certificate.
Known for
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How we checked
Certification claims here are verified against the certifier’s own database, not the brand’s marketing. Check them yourself:
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Kirkland Signaturetesting & certifications — FAQ
Is Kirkland Signature third-party tested?
Kirkland Signature reports the following quality programmes: USP Verified (about two dozen products, not brand-wide). USP verification is an independent, third-party program that confirms a product's identity, potency, and purity. We reproduce what the brand publishes; where the certifier keeps a public registry (NSF, USP, Informed Sport), look the specific product up there before relying on it — a company-wide claim is not a batch certificate.
Is Kirkland Signature USP Verified?
Kirkland Signature products are USP Verified. USP Verified means the U.S. Pharmacopeia independently confirms the product's identity, potency, and purity, and that it's made under good manufacturing practices.
How we assess supplement brands
Supplements aren't FDA recall-rated like prescription drugs, so we don't assign a recall-safety score here. Instead we report what a brand is independently verified for — NSF, NSF Certified for Sport, USP Verified, Informed Sport, cGMP, and batch testing — the signals that actually separate supplement quality. This is general reference, not medical advice; always consult a professional.