The rooibos tea substitute drink has side effects, nausea, vomiting, diarrhea, epigastric discomfort, and also bradycardia. It should not be taken in excess or for a long period of time to avoid poisoning.

"Shaanxi Chinese Herbal Medicine": "Light astringent flavor, cool nature, with a small poison."

"Xinjiang Chinese Herbal Medicine Manual": "Sweet and bitter taste, flat nature, with small poison."