Hydrox cookies are not available in stores. Leaf Brands owns the trademark name and states on its website, as of March 2015, that the cookies are coming back. However, the the Leaf Brands website also states to look for Hydrox cookies in late 2014, so there is apparently a delay.
Consumers first bought Hydrox cookies from local markets in 1908, four years before Oreos were available. For many years, the Sunshine Company produced Hydrox cookies. Keebler acquired the brand and then sold it to Kellogg's, who ended regular production in 2002, but briefly resurrected it for the 100th anniversary of the cookie, according to USA Today.
Oreo cookies were originally made using animal fats, while Hydrox cookies included only vegetable fats. This allowed Hydrox cookies to carry a kosher approval but prevented Oreos from making the same claim. Later changes to the Oreo recipe eliminated the lard, so Oreos earned the kosher label too, reports USA Today.
Most Baby Boomers grew up with two kinds of cream-filled chocolate sandwich cookies on the shelf, and USA Today indicates there is a big demand for Hydrox, what fans call the superior cookie. However, it has been over a decade since Oreos have had any competition other than store brands. If Hydrox does make it back to stores, the brand faces a big battle to rival Oreos, says USA Today.