What is camphor, and what is it used for?
Camphor is an aromatic flammable substance originally distilled from the bark and wood of the camphor tree, Cinnamomum camphora, but now produced primarily from turpentine oil.
Camphor is used as an active ingredient in ointments, camphorated oils and gels, which are topically applied on the skin to relieve local itching (pruritus) or pain, applied on the chest or throat to relieve cough and congestion, or added to steam inhalations to relieve cough.
Camphor works by counterirritation. Camphor initially irritates the nerve endings under the skin or mucous membranes, but continued exposure desensitizes the nerve endings and decreases their sensitivity to pain and itching, and reduces the urge to cough when inhaled.
Animal studies indicate that camphor desensitizes transient receptor potential vanilloid-1 (TRPV1) and transient receptor potential ankyrin (TRPA)1 ion channels on nerve cell (neuron) membranes. These ion channels on neuronal membranes detect environmental irritants and induce protective responses such as pain, heat or itching sensations, cough and tears.
Camphor has traditionally been used as an ingredient in many over-the-counter (OTC) cough and cold remedies, for fragrance in cosmetics and perfumes, and as a flavoring agent in food. Camphor balls are used as insect repellents and camphor was used as a fumigant during the Black Death, a plague that spread through Europe in the 14th century. In India, camphor pellets are burnt in temples during religious rituals.
Suggested topical uses of camphor include:
- Minor pains and itching from insect bites, minor burns and scrapes, and itching and rash from poison ivy, poison oak or sumac.
- Warts and cold sores
- Muscle aches
- Joint aches
- Backache
- Cough and congestion (also as steam inhalations)
Camphor is highly toxic when orally ingested or when products with high camphor content are applied for too long on the skin, particularly on infants. In 1983, the FDA evaluated the use of camphor because of many reports of camphor poisoning.
The FDA recognized camphor as a safe and effective topical antitussive, analgesic, anesthetic, and antipruritic agent, and set a product limit of 11% of camphor concentration. The FDA completely banned products labeled as camphorated oil, camphor oil, camphor liniment and camphorated liniment.
