Possible side effects of noni juice are liver damage and elevated potassium levels, according to WebMD. Pregnant and breastfeeding women should not consume noni juice.
The high level of potassium in noni juice can be harmful to individuals with kidney disease or those who take angiotensin-converting enzyme inhibitors, potassium-sparing diuretics or angiotensin II receptor blockers, according to About.com. Elevated potassium levels can cause the serious condition of hyperkalemia in these individuals. Any individual thinking about taking noni juice should first consult a doctor.
Noni juice is used to treat various conditions such as heart disease, arthritis, poor digestion, diabetes and depression, according to WebMD. However, there is insufficient evidence for its effectiveness.
Noni juice is derived from the fruit of the noni plant, a flowering shrub native to Asia, Polynesia, Australia and the Pacific Islands, according to About.com. Noni juice can be found in tablet, capsule, juice or liquid concentrate form.
Noni juice contains vitamins, minerals and antioxidants, according to About.com. The juice is believed to improve various health conditions due to the antioxidant content. Animal studies have shown very positive effects of very high doses of noni juice, but the effectiveness and safety of noni juice for humans is unknown.