1. Comfrey
Comfrey, a plant found in Asia, North America, and Europe, is sometimes used as a supplement to treat a range of conditions, including osteoarthritis, sprains, bruising, and more. However, as Thayer points out, this plant "contains chemicals called pyrrolizidine alkaloids that can cause severe damage to the liver." In fact, the FDA has recommended that all comfrey products taken by mouth are removed from the market due to these safety concerns. "As such, it is no longer available in the US market except as a cream or ointment."
However, Thayer warns that "Even still, large amounts can be absorbed through the skin and extreme caution should be taken when using this product," which means that it's likely best to avoid any product containing comfrey altogether. And luckily, there are tons of safer alternatives.
"There are other supplements that can give similar results as comfrey such as Arnica for bruising, sprains, and fractures, aloe, celery seed, ginger, and more for inflammation," Thayer points out. Anti-inflammatory foods are always a good, safe way to go. "With so many other alternatives to achieve the same results, it is not worth the serious risks you encounter to use comfrey. I would recommend avoiding altogether and using one of the many other supplements that can help you achieve the desired result." Noted!
2. Kava
Kava is one common supplement that has gained popularity due to its stress-relieving properties. Unfortunately, it could pose a serious risk to your liver, especially if you're already dealing with liver issues. "Research has indicated potential risks associated with kava consumption, with the most significant concern being liver damage," says Dr. Wong. "Some individuals have reported cases of hepatotoxicity," she notes, referring to liver damage from drugs and herbs. But unlike comfrey, kava supplements taken orally are still sold in the United States, so it's up to consumers to consider the risks at hand.
If you do choose to take kava, there are some steps you can take to reduce the risk of liver damage. "It's essential to discuss any new supplement or approach with a certified healthcare professional to ensure safety and efficacy for individual needs," Dr. Wong says. Noting that this is especially important if you have pre-existing liver conditions or are taking medications that may interact with kava.
Additionally, she says consumers should "limit the dosage and duration of use, as prolonged or excessive intake may increase the risk of adverse effects" and "choose reputable sources to ensure the product is of high quality and free from contaminants." But of course, the safest route is to avoid this supplement altogether.
READ MORE: A Dietitian Shares 3 Essential Foods For Your Liver, Gut, And Weight Loss