How it works
Menthol primarily activates the cold-sensitive TRPM8 receptors in the skin. Menthol, after topical application, causes a feeling of coolness due to stimulation of 'cold' receptors by inhibiting Ca++ currents of neuronal membranes. It may also yield analgesic properties via kappa-opioid receptor agonism.
Common side effects
Balance disorder (loss of balance), Vomiting, Altered heart rate, Drowsiness, Hypersensitivity reaction, Nausea, Abdominal pain, Contact dermatitis, Skin irritation, Apnea (absence of breathing), Nystagmus (involuntary eye movement), Vertigo, Coma