What Is A “Synthetic” Cannabinoid? A Chemist Discusses the Science.

This article discusses the controversial and widely misunderstood topic of so-called “synthetic” cannabinoids. This issue is important as legislatures across the country consider new hemp bills. 

I am grateful to chemist Mark Krause for providing a clear scientific explanation about what constitutes a “synthetic” cannabinoid and how that differs from an “isomerized” cannabinoid. Mark is the principal scientist of Krause Analytical Labs and a noted expert witness on chemistry matters with over 45 years of wide-ranging experience in multiple disciplines in chemistry. Mark has addressed this issue in podcasts and writings. He graciously allowed me to reprint a paper he wrote on the topic, entitled “Delta-8 THC is not a ‘synthetic’ cannabinoid”. The article is below in its unedited format.

Thanks also to Cynthia Cabrera of Hometown Hero and the Hemp Industries Association for connecting me with Mark. 

Here’s Mark’s paper- 

Delta-8 THC is not a “synthetic” cannabinoid

In the USDEA Controlled Substances Act “synthetic cannabinoids” are prohibited. This refers to a series of compounds synthesized by John W. Huffman at the University of Clemson, all based on a chemical structure known as a naphthoylindole. Mr. Huffman called these compounds “synthetic cannabinoids” due to the effect they had in the human body, mimicking the effects of tetrahydrocannabinols. These compounds are fully synthetic; they do not occur anywhere in nature to the best of our knowledge. They are commonly referred to as K2 or spice, or occasionally bath salts.

These compounds are not tetrahydrocannabinols (THC); they have a completely different structure than the THCs. THCs, on the other hand, are not necessarily “synthetic” as they occur naturally in the plant Cannabis Sativa L. (as well as other plants). There are synthetic forms of THC; however, for the most part, THCs are chemicals known as phytochemicals, or chemicals that naturally occur in plants due to biosynthesis or other natural biochemical pathways.

The term “synthesis” has a specific meaning in chemistry. Synthesis in organic chemistry has a very well-defined meaning that involves the reaction of two or more compounds (reactants) to produce one or more new compounds with a differing mass (products). Isomerization, on the other hand, involves only one reactant and produces compounds of the same mass by moving chemical bonds into a more favorable energy state. This is also referred to as rearrangement since physically what is occurring is a rearrangement of the chemical bonds within the molecule.

Cannabidiol, or CBD, is a phytochemical. It is an isomer of THC; that is, it has the same molecular formula and the same molecular weight as THC. CBD in the presence of sunlight, heat, pressure or a combination of these will isomerize to THC; that is, bonds within the molecule move into a more energetically favorable state. This can, and does, happen in the absence of chemical catalysts and is a well-known phenomenon during the drying/curing cycle of hemp. While there are processes involving catalysts that radically accelerate the isomerization of CBD to THC these reactions are inherently non-synthetic since they do not involve two or more reactants and they do not produce a product of differing mass. Indeed, merely heating CBD in a flask will lead to nearly complete conversion to either delta-9 THC or delta-8 THC without involving any other chemicals, solvents, catalysts, etc. in the process.

The moving of bonds to achieve a more favorable energy state is true within the isomers of THC, as well. For example, delta-9 THC will isomerize to delta-8 THC in the presence of light and heat. This requires no catalyst; depending upon the frequency of the light and how much heat is present this reaction will occur somewhere between minutes and months. This is the likely pathway to delta-8 THC in the Cannabis Sativa L. plant, since the typical biochemical pathway from CBG to THC is through the production of delta-9 THC.

While there are well-documented synthetic pathways to the THCs isomerization is not synthetic, and delta-8 THC derived from hemp is not a synthetic compound. Delta-8 produced legally from hemp clearly falls within the definition of hemp as published by the USDA and accepted by the USDEA in their respective definitions of hemp.

[Editor’s note – Krause’s last statement regarding delta-8 THC legally falling within the definition of “hemp” under the 2018 Farm Bill is supported in rulings by both the 4th Circuit and the 9th Circuit Courts of Appeal.]

January 23, 2025

Rod Kight is an international cannabis lawyer. He represents businesses throughout the cannabis industry. Additionally, Rod speaks at cannabis conferences, drafts and presents legislation to foreign governments, is regularly quoted on cannabis matters in the media, and is the editor of the Kight on Cannabis legal blog, which discusses legal issues affecting the cannabis industry. You can schedule a call with him by clicking here.