Terpenes and terpenoids are two different organic compounds, but their names often get used interchangeably. The difference between the two stems from their molecular makeup; terpenes naturally have no oxygen, but over time absorb incredibly small amounts. This process is called oxidation. As terpenes come into contact with air over time, this oxidation causes their genetic makeup to subtly change. The end result of this process is a terpenoid.
Different terpenes will oxidize at varying rates, which has lead to a mix of terpenes and terpenoids being present in most cannabis on shelves. The changes that a terpene undergoes to become a terpenoid can range from fairly minor to incredibly complex. For example pinene is a central terpene in many strains of cannabis, and it’s also known to form other terpenes and terpenoids when reacting with various chemicals. One organic compound that pinene can produce is limonene. Pinene itself begins as a terpene, while the resulting limonene in this example is a terpenoid. The key difference between the two is that during this chemical reaction, oxidation dries it all out and changes them from ‘wet’ terpenes to oxidized and ‘dry’ terpenoids.
These terpenoids provide similar effects as terpenes, although with a range of differences. Flavor can be partially lost, while relaxation, muscle recovery, and many other effects remain. Sometimes even in increased amounts! The rate of these changes can vary from terpene to terpene, which can explain the mix of terpenes and terpenoids found in dried and cured cannabis. This also happens to rosin as it cures. The longer a terpene is left to oxidize, the more it can dry out. To avoid oxidation and maintain terpenes’ original qualities leave products sealed in a cool place, such as the refrigerator.