The caffeine in green coffee can contribute to a wide range of side effects, including headache, upset stomach, anxiety and insomnia, according to WebMD. Caffeine can also impact the way that sugar is processed, potentially making it less safe for diabetics who do not monitor their health.
Green coffee is produced from beans that have not been roasted, which results in a higher amount of chlorogenic acid in the coffee. Chlorogenic acid can help aid weight loss and lower blood pressure, primarily when taken in the form of a green coffee extract supplement. Svetol and Naturex are two pills that contain green coffee extract.