It didn't take too long for the UFC to let go of Lavar Johnson. The heavyweight was flagged for elevated testosterone levels following his defeat to Brendan Schaub at UFC 157. On March 1st, Johnson said he was thankful he still had a job with the UFC. As of yesterday (per MMA Junkie), he no longer has a job with the promotion.
Since Dana White announced that the UFC was planning to release roughly 100 fighters from the roster, the leash on those who have either mediocre records or at least one failed drug test (or both) has tightened. The UFC recently cut Matt Riddle and Riki Fukuda for failing their drug tests, although Riddle was the only one to win his bout.
Johnson went 2-2 under the UFC banner, with KO/TKO wins over Joey Beltran and Pat Barry, and losses to the aforementioned Schaub and Stefan Struve. In addition to his release, he's suspended for nine months by the California State Athletic Commission.