Some of Costco's Kirkland Signature diapers are believed to be manufactured by Kimberly-Clark, the company behind the Huggies brand.
It is speculated that some of Costco's Kirkland Signature haircare products, such as shampoos and conditioners, are made by L'Oréal, the parent company of Pureology.
Costco's Kirkland Signature French Vodka has been said to be produced by the same distillery that makes Grey Goose.