Huperzine B is also an acetylcholinesterase inhibitor, but because its effects are much weaker than those of huperzine A, most research has focused on huperzine A.

• 石杉碱乙同样也可以抑制乙酰胆碱酯酶，但由于其效果弱于石杉碱甲，故偏重于石杉碱甲的提取。