Alkenylbenzenes, such as estragole, myristicin and eugenol, are present is several flavourings, functional foods, plant food supplements (PFS) and in complementary and alternative medicines (CAM) including herbal medicines. The increase in consumption in functional foods observed worldwide requires a strict analysis of the scientific validity of their benefits and risk-benefit ratio associated with their intake. Some instances of acute toxicity have been reported associated with the use of herbal medicines and PFS, in particular because quality control is poor, and this poses a risk especially in internet marketed products. In particular, chronic exposure to low levels of these constituents may pose a hazard. However, given the variability in dietary habits, plant properties, plant misidentification or interaction with pharmaceutical drugs or nutrients, the assessment of risk due to the intake of alkenylbenzenes is difficult. We herein review the regulatory status of the most common alkenylbenzenes and their genotoxic activity and potential carcinogenic activity.