About 25 million Americans suffer from heartburn on a daily basis, while more than 60 million people in the U.S. deal with heartburn symptoms like pain and burning at least once a month. One natural substance sometimes touted as a natural heartburn-fighter is D-limonene, a compound sourced from citrus-fruit peels and sold in dietary supplement form.

Although few scientific studies have tested D-limonene’s effectiveness against heartburn, there’s some evidence that supplement shows promise for heartburn control. In a 2007 research review published in Alternative Medicine Review, for instance, investigators found evidence that D-limonene may help ease heartburn by neutralizing gastric acid and regulating the contraction of muscles in the digestive tract.

If you’re seeking a natural solution for heartburn relief, some studies show that herbs like licorice, slippery elm, and marshmallow may be beneficial. You can also fend off heartburn by avoiding trigger foods, eating smaller portion sizes, and working to manage your stress levels. More on d-limonene.