No, it's been opened and I used 1/3 of it, probably sometime in 07 or 08. I'm not worried that it's toxic, just curious if the ingredients are still potent enough to do what they need to do. I like the convenience of caps so I'd probably buy some capped MCC, but since I'm only dosing on non-WO days, I'd hate to waste this bottle if it's at all able to be used.