actually thats just from too much chlorophyll, which can be quite irritating and with some already being sensitive to chlorophyll it makes it worse. also theres some calcium oxalate and other compounds, which really shouldnt be consumed in such concentration. no different than chugging carrot juice or something, youll end orange or another common problem is vitamin a overdose (not talking about cannabis here)
not to say yiu cant develop an allergy
there arent really that many benefits to juicing cannabis as to recieve medical benefits receptors need to be hit and most of them lie under the blanket of protection surrounding your brain.
i mean if you want some of my thoughts i can give links
https://www.rollitup.org/t/juicing-cannabis.874281/#post-11690585