Hydrox is the brand name for a creme-filled chocolate sandwich cookie manufactured by Leaf Brands. It originally debuted in 1908, and was manufactured by Sunshine Biscuits for over ninety years. The similar Oreo cookie, introduced later in 1912, was inspired by the Hydrox. However, the Oreo eventually exceeded it in popularity which resulted in the Hydrox coming to be perceived as a knockoff, even though it was the original. Hydrox was largely discontinued in 1999 after Sunshine was acquired by Keebler, which would later be acquired by Kellogg's. In September 2015, the product was re-introduced by Newport Beach-based Leaf Brands. Compared to Oreos, Hydrox cookies have a tangy, less-sweet filling and a crunchier cookie that gets less soggy in milk.
Hydrox derived its name from the atoms that make up the water molecule (hydrogen and oxygen). In 1908, the creators of the cookie were looking for a name that would convey "purity and goodness."
Sunshine Biscuits was purchased by Keebler in 1996, and in 1999, Keebler replaced Hydrox with a similar but reformulated product called Droxies. Keebler was later acquired by Kellogg's in 2001. Kellogg's removed Droxies from the market in 2003. Kellogg's marketed a similar chocolate sandwich cookie under the Famous Amos brand, along with sandwich cookies of other flavors, but has since discontinued the line.
On the cookie's 100th anniversary, Kellogg's resumed distribution of Hydrox under the Sunshine label, with the first batches shipped in late August 2008. Hydrox aficionados had bombarded Kellogg's with thousands of phone calls and an on-line petition asking that production resume. The recipe was slightly altered from the original; trans-fats were removed. The cookies were to be available nationally for a limited time, and less than a year later Kellogg's had removed Hydrox from their web site.
The Carvel ice-cream franchise sold ice-cream goods manufactured with "Hydrox" cookie crumbs until 2012. Carvel used the cookies' all-kosher status as a selling point as the original Oreo recipe used lard. The cookies were not specifically mentioned by name on the Carvel website, but they were identified as hydrox (lower-case 'h') on the in-store posters. Carvel currently uses Oreo cookies in its ice cream goods.