When it comes to supplements labeled as “all-natural,” many assume they’re automatically safe. However, experts warn that even herbal remedies can pose serious risks—especially when taken in excess or without medical supervision. Two supplements in particular, licorice root and kava, have been linked to potentially harmful side effects that may affect the kidneys and liver.
1. Licorice Root
While licorice root is often praised for its digestive benefits and use in herbal teas, doctors caution that overuse can do more harm than good. When consumed in large amounts or over extended periods, licorice root can lead to potassium depletion and elevated blood pressure—two factors that may contribute to kidney damage or worsen preexisting kidney conditions.
“Licorice root can be harmful to kidney health due to its effect on potassium levels and blood pressure,” warns Dr. Rimas Geiga.
If you’re seeking digestive relief, experts recommend safer herbal alternatives such as chamomile or fennel tea. Both can help soothe the stomach naturally without the potential risks associated with licorice root.
2. Kava
Kava, a popular herbal remedy often used to promote relaxation and ease anxiety, may not be as harmless as it seems. “Kava, which is typically consumed as a tea, is a supplement known to promote relaxation,” explains Jesse Feder, RDN, CPT. However, this sense of calm may come at a cost.
“Consuming kava regularly has been shown to affect enzyme and antioxidant activity in the liver which can lead to liver damage,” Feder warns. In addition, kava may also impact kidney health. “Kava may decrease blood flow to the kidneys and cause increases in harmful metabolites which can also damage them,” she adds.
As with any supplement, experts emphasize the importance of moderation. Always follow recommended dosages, and only purchase from high-quality, reputable brands to reduce the risk of contamination or side effects.
While natural remedies can support wellness when used responsibly, “natural” doesn’t always mean “safe.” Before adding supplements like licorice root or kava to your routine, consult with a healthcare professional—especially if you have underlying kidney or liver conditions.

