Natural constituent of plant oils such as those from rose, basil, blackberry, cinnamon, and anise. According to the November 9, 1998, issue of The Rose Sheet (an insider cosmetics industry newsletter), the National Toxicology Program Board of Scientific Counselors concluded that “methyleugenol, a component of a number of essential oils, has shown clear evidence of carcinogenic activity in male and female rats and mice.” The study is an animal model and so the results may or may not be applicable to humans.