Antracompounds, which are one of the main ingredients of herbs, derived from anthracene have a laxative effect - laxantia (slightly laxative) and purgantia (strongly laxative). Herbs with antracompounds are: aloe, rheum rhizome (rhubarb), buckthorn bark, and buckthorn, senna leaves and others. Some ingredients in herbal blends have a synergistic effect. Rheum rhizome and senna leaves produce red urine. The use of improper blends can cause side effects (e.g. Intestinal contraction). Use of the blends containing aloe vera is not recommended for pregnant women as it can cause miscarriage.