Who makes Kirkland Signature Ultra Strength Antacid, Calcium Carbonate 1000 mg, 530 Chewable Tablets (2 x 265)?
As of August 30, 2026, the manufacturer of Kirkland Signature Ultra Strength Antacid, Calcium Carbonate 1000 mg, 530 Chewable Tablets (2 x 265) is Guardian Drug Company, Inc., per recall notice evidence.
The common claim
What most answers say — and what the evidence supports
Most online answers do not name a maker for Kirkland Signature Ultra Strength Antacid - they describe it as Costco's calcium-carbonate store-brand alternative to Tums (a Haleon brand) and stop there, and a few assume it shares a maker with Tums - an assumption FDA's June 2026 recall records partly support, since Guardian Drug was also the recalling firm for specific Tums lots in the same event. FDA records identify the maker: the antacid is manufactured by Guardian Drug Company, Inc. of Dayton, New Jersey, for Costco Wholesale, per the FDA drug label for NDC 63981-171 and a May 2026 FDA Class II recall notice that reproduces the package's 'MANUFACTURED BY: GUARDIAN DRUG COMPANY, INC. ... FOR: Costco Wholesale Corporation' statement. Guardian Drug is a Dayton, New Jersey contract manufacturer of store-brand over-the-counter products - antacids, laxatives, analgesics, and cough/cold/allergy items, per its own site.
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 2
Class II recall, firm-initiated 2026-05-28 (center classification 2026-06-03, report date 2026-06-10, distribution U.S.A. nationwide). Recalling firm: Guardian Drug Co. Inc., 2 Charles Ct, Dayton, NJ. The product_description reproduces the package's own manufacturer statement verbatim: 'KIRKLAND Signature, ULTRA STRENGTH ANTACID, Calcium Carbonate, 1000 mg, 265-count bottle, MANUFACTURED BY: GUARDIAN DRUG COMPANY, INC., 2 CHARLES COURT/DAYTON, NJ 08810, FOR: Costco Wholesale Corporation, 999 Lake Drive, Issaquah, WA 98027, NDC 63981-171-80.' Reason for recall: 'Presence of foreign substance: small metallic particles in chewable tablets.' A recall notice reproducing the on-label 'Manufactured by ... For Costco' block directly names the maker of this exact NDC (tier 2). The same recall event (FDA event 99098) lists Guardian Drug Co. Inc. as the recalling firm for two Haleon Tums products as well - D-0558-2026 ('HALEON CALCIUM CARBONATE TUMS ANTACID, Assorted Fruit Tablets, 1000 mg, 160-count bottle, Haleon, Warren, NJ 07059', lots 1096075-1096078) and D-0559-2026 (750 mg, 330-count, lot 1076169), same reason and dates - which bears on the Tums FAQ below, not on the Kirkland attribution. Both records archived: https://web.archive.org/web/20260831015308/https://api.fda.gov/drug/enforcement.json?search=recall_number:%22D-0558-2026%22&limit=1 and https://web.archive.org/web/20260831015321/https://api.fda.gov/drug/enforcement.json?search=recall_number:%22D-0559-2026%22&limit=1
Tier 3
FDA Structured Product Label for NDC 63981-171 (package 63981-171-80, marketed since 2024-07-08). Labeler: Costco Wholesale Company (DUNS 103391843). The SPL establishment table names Guardian Drug Company (FEI 119210276) performing the operation 'MANUFACTURE(63981-171)' - the FDA-registered manufacturing establishment for this NDC, corroborating the recall. The product ships as an OTC monograph drug (application number M001), so openFDA's manufacturer_name field only echoes the labeler (Costco); the establishment block, not that field, carries the naming. FDA's own record misspells the brand as 'Ultra Stregth Antacid'.
Tier 4
Guardian's own self-description, cited only for what the company says it does: "Guardian Drug Company is a major supplier of Antacids, Laxatives, Analgesics, Cough/Cold and Allergy products to leading drug store chains, mass merchandisers, supermarkets, wholesalers, and distributors across the nation," with a Dayton, New Jersey facility "expanded ... to over 400,000 sq feet" and contract manufacturing. It does not name Costco or Kirkland; the tier-2 recall and tier-3 SPL above carry the attribution.
Frequently asked
Who makes Kirkland Signature Ultra Strength Antacid?
Is Kirkland antacid the same as Tums?
Was Kirkland Ultra Strength Antacid recalled?
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