A very small percentage of people may have side effects such as headaches and stomach ache, due to natural alternative sweeteners like monk fruit and Stevia. Monk fruit is made from juice of the Monk fruit (Buddha fruit, luo han guo) from Southeast Asia. The juice itself contains natural sugars like fructose and glucose, but these are removed during processing. The sweetness comes from antioxidants, so you get the sweetening effect with extra benefits. Stevia is also derived from a plant and is far sweeter than sugar without impacting your blood sugar or insulin response. However, many mainstream brands combine Reb A (the most common form) with things like sugar alcohols, maltodextrin, or dextrose, as well as natural flavors. These won’t have a huge impact on your blood sugar, but having too much of them might cause some GI issues. Stevia does have a bit of a licorice flavor - some even describe it as bitter - and, though rare, there is a chance of allergies with stevia (it’s part of the chrysanthemum/ragweed family), so we prefer monk fruit for those reasons.