Mushroom coffee is a trendy drink that’s billed as a healthier alternative to regular java. The beverage blends functional mushrooms and superfoods with coffee beans to offer a range of health benefits, including reduced stress, improved immunity and balanced digestion. However, the new brew also has its share of downsides, particularly for those with sensitive digestive systems and those who are prone to kidney stones.

Mushroom coffee may contain high levels of oxalates, which are known to increase the risk for developing kidney stones. Moreover, certain types of mushroom extracts used in the brew (particularly the chaga variety) may be hard on the gut. As such, the brew is best avoided by those with sensitive digestive systems and those who are susceptible to oxalates.

Caffeine-Free Mushroom Coffee Options

While the brew may have some promising health claims, more research including human studies is needed to verify those claims, according to Sarah Olszewski, a registered dietician and founder of the food and wellness counseling practice Sarah Lynn Nutrition. That said, she recommends incorporating the drink into a balanced diet if you’re interested in trying it.

Olszewski’s pick for a caffeine-free mushroom coffee is MudWTR, a plant-based blend made with functional mushrooms and ayurvedic herbs. She cites its calming effects as a big selling point, along with the fact that the drink has less than half the amount of caffeine in traditional coffee. The drink is also vegan, gluten-free, and free of added sugar. It’s made with organic shade-grown coffee beans, lion’s mane, cordyceps and chaga mushrooms.