I had a similar yet different problem where when i consumed it, it wouldn't necessarily kill me but my health would drop very low and my character would fall to the grow and wont be able to get back, pretty much soft locking me. It only worked one time, but only on one of the potions, and I had no idea what allowed me to stay alive that one time.
I'm having the same problem I have all 3 dank potions still even after drinking one am I'm not sure what to do of it. I'm also not sure how I get the pesticide potion to kill the roots. I know about the root monsters you can kill every 15 or so floors in dungeons but I guess thoughs have nothing to do with getting this potion I need. Can I please have help?