According to a quick Amazon search, Still Alice will be released on DVD on July 6th 2015.
There may be sites which allow you to pre-order the Still Alice dvd before then, but it's likely that most distributors will only ship the movie around the July release date.
The movie has only been out in cinemas since December 5th, and most movies are given a few months to try and take in as much at the box office before they appear on dvd.
The movie does look like it's worth checking out though - it received a 90% rating on movie review website Rotten Tomatoes.
