Terpenes are volatile organic compounds found naturally in plants, primarily responsible for their distinctive aromas and flavors. The question of whether these compounds cause a cough is common, especially among consumers who use vaporization or concentrates. Terpenes can cause a cough, but the relationship depends on several factors, including concentration and method of delivery. This reaction is a protective reflex triggered by inhaling highly concentrated or chemically altered irritants.
What Exactly Are Terpenes
Terpenes are a large, diverse class of organic hydrocarbons produced by most plants, including citrus fruits, pine trees, and aromatic herbs. They are the major components of plant essential oils and serve functions like attracting pollinators and deterring predators. The compounds are categorized based on their chemical structure, which determines their specific aroma and physical properties.
Common examples include limonene, which gives citrus its scent, and pinene, which contributes the aroma of pine needles. Myrcene is another widely studied example, found in hops and mangoes.
The Mechanism of Respiratory Irritation
The cough reflex is the body’s natural defense mechanism, designed to forcibly expel irritating substances from the airways. When inhaled in vapor form, terpenes can act as chemical irritants to the mucous membranes lining the throat and lungs. Their high volatility allows them to readily transition into a gaseous state and make direct contact with respiratory tissues.
Certain terpenes, such as 3-carene, irritate mucous membranes. Inhaling these compounds at high concentrations triggers sensory nerves in the airways. This stimulation signals the brain that a foreign substance is present, initiating the reflexive, forceful contraction of the diaphragm and chest muscles known as a cough.
The Role of Delivery Method and Concentration
The likelihood and severity of a terpene-related cough are significantly influenced by consumption method and concentration. Delivery methods involving high heat, such as dabbing or high-temperature vaporization, cause thermal degradation of the terpenes. When exposed to excessive heat, terpenes break down into smaller, highly reactive, and more potent respiratory irritants.
For instance, pinene and myrcene can degrade into harmful byproducts like methacrolein and benzene at high temperatures. These compounds activate the pain and heat receptors in the airway that trigger the cough reflex. Localized hotspots in vaporization devices, which can exceed 250°C (482°F), can cause this chemical breakdown even if the device’s display shows a lower temperature.
Concentration is also important, especially in refined products like vape cartridges and concentrates. Natural terpene content in plant flower typically ranges from 0.3% to 2.3%. However, some commercial extracts are heavily fortified with added terpenes for flavor enhancement. Inhaling these highly concentrated solutions can overwhelm the respiratory system, leading to a harsher, more immediate cough response. This high concentration increases the total chemical load of irritants entering the lungs.
Strategies for Reducing Terpene-Related Coughing
One effective strategy for minimizing irritation is to lower the temperature settings on vaporization devices. Reducing the temperature below the point of thermal degradation, generally keeping it between 180–190°C (356–374°F), prevents the formation of harsh breakdown products. This lower heat ensures terpenes are vaporized gently without converting into potent irritants.
Users of concentrates should ensure their products are properly diluted and avoid excessive terpene additives. Taking smaller, more measured inhalations also reduces the volume and intensity of the vapor reaching the lungs. Maintaining hydration by drinking water before and during consumption is a simple measure to soothe the throat and keep mucous membranes moist. Regularly cleaning vaporization equipment prevents the re-inhalation of accumulated, degraded residue, which contributes to airway irritation.