Brief: Ingredients in commonly used products such as toothpaste, balms, and various essential oil-based items have the potential to stimulate brain neurons. Over time, this may contribute to the development of neurological disorders, making it an important area of research in neurotoxicology.
These insights are based on clinical observations in patients suffering from a range of neuropsychiatric conditions, particularly headaches and seizures. Recent publications on the stimulatory effects of essential oils on the brain have implicated oils such as camphor and eucalyptus in triggering seizures and breakthrough seizures in individuals with epilepsy.
These findings prompted a detailed evaluation of other ingredients found in products like toothpaste, hair oils, and balms, and their potential effects on brain health. Many of these substances can be absorbed through the buccal mucosa, bypassing first-pass metabolism in the liver. This allows them to directly cross the blood–brain barrier and stimulate neurons through a process known as chemical kindling. This phenomenon occurs when brain neurons are repeatedly exposed to a stimulus—especially at intervals of 24 to 48 hours—leading to the formation of hyperexcitable neurons, circuits, and networks across various brain regions. Such changes may underlie the development of disorders like migraine, seizures, and epilepsy.
Preliminary studies have associated exposure to certain ingredients with conditions such as migraine , cluster headaches, trigeminal neuralgia, functional vertigo, hemibody pain, seizures, epilepsy, anxiety, panic attacks, psychosis, and depression. A case series published in The International Journal of Head and Face Pain in 2021 reported cluster headaches associated with toothpaste use, with complete resolution of symptoms within 1–2 weeks after discontinuation. Patients with migraines have also reported significant reduction in headaches after stopping the use of toothpaste and over-the-counter balms. In exploratory studies using adult zebrafish models, exposure to toothpaste was associated with increased hyperactivity, aggression, and anxiety.
Ingredients such as sodium lauryl sulfate, sodium methyl hydroxybenzoate, and flavoring agents like menthol, camphor, and eucalyptol are known to activate TRP channels and increase the release of calcitonin gene-related peptide (CGRP), which can worsen migraines and cluster headaches. Other compounds such as silica, potassium nitrate, arginine, and titanium dioxide may elevate nitric oxide levels, potentially triggering headaches. Camphor and eucalyptol have been shown to block potassium channels, increasing neuronal excitability and causing erratic firing patterns, as demonstrated in animal studies involving snail neurons. Additionally, ingredients like sodium fluoride, sorbitol, sodium benzoate, and titanium dioxide may disrupt the gut–brain axis. Alterations in gut microbiota have been linked to conditions such as autism, multiple sclerosis, and other neuropsychiatric disorders, including depression. Replacing toothpaste with inert alternatives such as water or saline may significantly reduce the burden of neuropsychiatric conditions like migraines, cluster headaches, and anxiety. Further research is warranted in this area due to its significant public health implications.
About the speakers: Prof. Thomas Mathew, MD, DM, is a Professor of Neurology and Vice-Dean for the Postgraduate Program at St. John’s Medical College, Bengaluru. He completed his MBBS at Kottayam Medical College, Kerala, MD at JIPMER, Pondicherry, and DM at NIMHANS, Bangalore. He is a member of the ICMR National Task Force Committees for Multiple Sclerosis and Stroke. His current research focuses on essential oil-related brain disorders and their implications in various neuropsychiatric conditions such as functional vertigo, anxiety, and psychosis. In 2015, he pioneered the use of Rituximab for Multiple Sclerosis in India. Prof. Mathew has published around 153 papers in national and international journals. In 2019, the Indian Academy of Neurology selected him to represent India at the International Headache Master School held in Sydney, Australia. He is the author of the book ABCDE of Weight Loss, written to help people struggling with obesity. He is the founder of the “Forum of Neurologists Against Multiple Sclerosis” and the Founder-Director of Nerve Care Innovations Pvt. Ltd., a company dedicated to innovations in medicine and neurology. In recognition of his contributions to Indian neurosciences, he was awarded the Fellowship of the Indian Academy of Neurology in 2022.