Menthol Overdose. Menthol is used as a flavoring agent for candy and other products. This article discusses menthol poisoning from swallowing pure menthol. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National Poison Control Center at 1-800-222-1222.