A 26-year-old Chinese man died in December after consuming excessive amounts of an herbal supplement meant to cure hair loss.

Central European News (CEN) reported that Cui Fei, from the eastern Chinese province Anhui, died of liver failure after consuming over 6.6 pounds of a supplement called TuberFleeceflower. Also known as Fallopia multiflora, heshowu, or Chinese knotweed, the plant is used in traditional Chinese medicine. The herb is also sold in the United States.

In 2014, the China Food and Drug Administration, which regulates food, drugs and medical devices in the country, issued a warning about the herb’s potential side effects, which include liver failure.

CEN reported that Jin’an Hospital was one of the medical centers that prescribed Cui with the hair-loss treatment, but that the hospital said the dosages it gave him were within the normal recommended limits. The hospital also said it has a policy that requires doctors to check for side effects of the herb every two weeks.

Cui, who had recently graduated from Central South University of Forestry and Technology in Changsha, the capital of central China’s Hunan Province, reportedly became ill two weeks into taking the herb. In August, doctors diagnosed him with drug-induced liver damage, and Cui stayed in the hospital for four months up until his death.