[4] In 1908, the cookie's creation was inspired by "purity and goodness", with a name derived from the hydrogen and oxygen elements within the water molecule.

[4] On the cookie's 100th anniversary, Kellogg's resumed distribution of Hydrox under the Sunshine label in late August 2008 in direct response to 1,300 phone calls from fans as well as an online petition with 1,000 signatures, a Hydrox fan website with the essay "Nonconformists don't eat Oreos", and dozens of forum posts, asking that production resume.

The cookies were available nationally for a limited time, and less than one year later Kellogg's removed Hydrox from their web site.

[5] The Carvel ice cream franchise sold ice-cream goods manufactured with Hydrox cookie crumbs until 2012.

[6] Leaf began production of its version of Hydrox on September 4, 2015, at the company’s facility in Vernon, California.