Moringa is a popular herbal supplement that is often taken for its purported health benefits. However, like any other supplement, it can cause side effects in some people. The most common side effects of taking moringa include upset stomach, diarrhea, and headaches. Some people may also experience allergic reactions to the herb, such as skin rashes or difficulty breathing. If you experience any adverse reaction after taking moringa, stop taking the supplement and consult your doctor immediately.