IMHO, I find it really dodgy as hell. Just by searching "Ceva Nembutal" in google images, you can see quite a few potential scamming websites employing the same "write on paper" technique. Besides, the label itself looks like a lazy job created by some ill-knowledged person. "ISBN" stands for "International Standard Book Number ", it is used for as an identifier for books only. Plus, the sequence of serial number also looks very fake and sloppy. The person's laziness goes beyond the horizon, he doesn't even bother to use the copyright symbol after the word "Nembutal", but an "@" symbol instead. Lastly, the legit bottles from this brand look like they use gloss paper. This person's paper looks like your common printing paper.
Based on my instinctive experience on scams since the late 90s, makes me lean towards calling this a fake. But hey, it's your decision and money, best of luck.