The seed is toxic for human.Large amount can cause vomiting, abdomen pain, diarrhea, mucus and blood in stool and can irritate the kidneys and cause bleeding.

• 牵牛子对人体有毒性，大量使用除直接引起呕吐、腹痛、腹泻及粘液血便外，还可刺激肾脏，引起血尿，严重者可损及神经系统，发生语言障碍、昏迷等。