Further cases of liver harm have come to light from taking common dietary supplements.
In February health officials reported 14 cases of liver harm linked to Arthrem and other products containing Artemisia annua extract.
The Ministry of Health said since then a further 11 reports have been made, some showing serious harm.
It said people should be aware of the risks from taking the products.
Medsafe suggests people should seek medical advice if they're feeling sick, have stomach pain, pale stools, dark urine, itching all-over, yellow eyes or skin.
Since the reports of liver harm were made, the ministry said most patients had either recovered, or were improving.