Who makes Kirkland Signature Krill Oil 500 mg, 180 Softgels?
As of August 10, 2026, evidence points to WN Pharmaceuticals as the manufacturer of Kirkland Signature Krill Oil 500 mg, 180 Softgels, but no tier 1–3 source names the link directly.
The common claim
What most answers say — and what the evidence supports
Nearly every online answer names Aker BioMarine, the Norwegian company that harvests Antarctic krill and sells the Superba krill oil ingredient. Aker's own investor materials stop at Costco's door: its February 2026 results release reports that the company 'supplied significant volumes of Superba Krill Oil to new customers, including a successful product listing at Costco,' and its CEO cited 'launch of a new krill oil brand in Costco' - but no Aker document names Kirkland Signature, and an ingredient supplier is not the finished-product manufacturer. For the softgels themselves, Costco's own product-listing data points to WN Pharmaceuticals, the British Columbia contract manufacturer behind the webber naturals brand.
Evidence & sources
Every source is graded on the six-tier rubric and archived, so the citation holds even if the original moves or paywalls. The tier badge grades the source; the status grades our confidence in the maker.
Tier 4
Costco's own page embeds catalog JSON whose manufacturer field names the finished-product maker: the item record with shortDescription 'Kirkland Signature Krill Oil 500mg, 180 Softgels', longDescription 'One Softgel per Day; Contains Omega-3 Fatty Acids, Phospholipids and Astaxanthin; 100% Krill Oil; USP Verified', startDate 2024-08-14, carries mfName 'WN PHARMACEUTICALS INC'. WN Pharmaceuticals is the British Columbia contract manufacturer behind the webber naturals brand, a long-standing Costco supplement vendor. Graded probable rather than confirmed because it is an internal catalog field, not an editorial statement - a sibling record for the same product carries the placeholder 'DO NOT DELETE', showing the field's data-quality noise - and it could reflect the vendor of record rather than the encapsulating plant, though for private-label supplements those are normally the same company.
Tier 4
Anchors the common claim's kernel of truth on the ingredient side without naming the brand: 'During the quarter, the company supplied significant volumes of Superba Krill Oil to new customers, including a successful product listing at Costco,' and CEO Matts Johansen: 'It was also particularly exciting with launch of a new krill oil brand in Costco during the quarter.' Neither sentence names Kirkland Signature, and an ingredient-supply statement does not establish who manufactures the finished softgel - included because it is the closest any Aker document comes to the widespread 'Aker BioMarine makes Costco's krill oil' claim.
Frequently asked
Who makes Kirkland Signature krill oil?
Is Kirkland krill oil made by Aker BioMarine?
Is Kirkland krill oil USP verified?
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