When trying to determine if Lex is good or bad there are certain steps that must be followed.
Step 1 - Take off his outer wrapping
Step 2 - Sniff him
Step 3 - Check his expiration date (generally stamped into the outside of his right thigh)
If he smells funny, and he's past his expiration date, he's bad.
DO NOT under any circumstances, consume a bad Lex. You could wind up in the emergency room.