What Types of THC Exist in the Cannabis Plant?
Cannabis enthusiasts will have heard of the cannabinoid THC, but many may not know that there are several different types of THC. The cannabis plant is full of cannabinoids; though the most well-known are THC and CBD, there are more than 100 different cannabinoids found in cannabis plants.
Delta-9 THC, or tetrahydrocannabinol, is the main psychoactive compound in marijuana. It is this compound that provides users with the "high" often associated with the consumption of cannabis products. Delta-9 THC binds with cannabinoid receptors in the brain to produce effects like pain relief and altered sensory perception.
Other types of THC—including THC isomers, analogs, and homologs—appear to offer many similar therapeutic benefits to Delta-9, along with a generally (but not always) milder high. If you’re interested in natural plant healing or simply want a good time, understanding each type of THC and its potential benefits can help you tailor your cannabis experience to your needs and goals.
THC Isomers
An isomer is a compound that has the same chemical formula as another compound but a different arrangement of atoms. The cannabis plant naturally contains two known isomers of the psychoactive compound Delta-9 THC:
Delta-8 THC, which has a double bond at the eighth carbon atom
Delta-10 THC, which has a double bond at the tenth carbon atom
As the name suggests, Delta-9 THC has a double bond at the ninth carbon atom. While this may seem like a very small difference, the change in structure leads to each molecule having somewhat different properties and effects.
Delta-9 THC
When we talk about “THC,” we’re usually referring to Delta-9. It is the most abundantly found type of THC and also the most studied compound found in the cannabis sativa plant.
Delta-9 produces mind-altering effects by binding to the CB1 receptors found in the brain and nervous system. This can produce feelings often associated with a "high" such as disassociation, relaxation, euphoria, and memory loss.
Though Delta-9 is most well-known for its psychoactive effects, its therapeutic properties have also been studied. Possible medical benefits of Delta-9 include:
Improved sleep
Relief from pain, especially chronic pain
Relief from nausea and vomiting, especially in the context of chemotherapy
Appetite stimulation
Delta-8 THC
Delta-8 is a lesser-known compound that makes up less than 1% of the cannabis plant. Because it exists in such scant quantities, producing marketable Delta-8 THC naturally wouldn’t be feasible. The Delta 8 THC you’ll typically find has been produced artificially from either CBD or Delta-9 THC.
Research into Delta-8 and its medicinal properties isn't as comprehensive as research on Delta-9. However, some studies have demonstrated that its consumption can produce energizing effects along with pain relief and relaxation. Another study shows that Delta-8 THC may be helpful for multiple sclerosis, although further research is needed.
Delta-10 THC
Delta-10 THC also causes different effects to Delta-9 despite having similar chemical properties. Its effects have been described anecdotally as promoting euphoria and focus and it’s said to produce a milder high. Because Delta-10 is present in such low concentrations in the marijuana plant, commercial Delta-10 THC products have usually been chemically converted from either CBD or Delta-9 THC.
THC Analogs
In addition to isomers, THC has a few analogs. Analogs are compounds with similar structures that differ in one component. The difference in composition is the reason these minor cannabinoids produce different physiological effects.
THCA (Tetrahydrocannabinolic acid)
THCA is the non-psychoactive acidic precursor to THC (see our article on THCA vs THC for a detailed explanation). It has a low binding affinity to CB1 and CB2 receptors.
THCA is of great interest to researchers in the area of medical marijuana use; THCA hasanti-inflammatory, immunomodulatory, antiemetic, and neuro-protective properties that could theoretically help with a wide range of medical conditions.
THCV (Tetrahydrocannabivarin)
Due to its slightly different structure, THCV doesn't bind as strongly to CB receptors as Delta-9. THCV is non-psychoactive in low doses but has psychoactive effects at higher doses.
Research indicates that THCV suppresses appetite and upregulates metabolism, giving it its nickname of "diet weed." THCV is present at higher concentrations in certain strains, including AC/DC, Durban Poison, and Jack the Ripper.
THC Homologs
Finally, there are at least two known THC homologs in the cannabis plant. Homologs have the same chemical formula but a different carbon chain length. THCP and THCB are two THC homologs that have recently begun to be studied by researchers.
THCP (Tetrahydrocannabiphorol)
THCP was only discovered in 2019. According to studies, THCP has a high binding affinity to both CB1 and CB2 receptors and is:
33 times more active than THC
63 times more active than THCV
13 times more active than THCB
The same report that quantifies its activity level describes THCP as having analgesic properties and causing hypomotility (slower movements). This leads researchers to suspect that its effects are similar to those of regular THC, only stronger.
THCB (Tetrahydrocannabutol)
THCB is another homolog of THC. It has a butyl side chain rather than a pentyl side chain. This compound displays an affinity to CB1 and CB2 receptors and has been tested in vivo for potential therapeutic effects in the areas of pain relief and inflammation (we’re still waiting for the results). THCB, along with CBGA, was found to inhibit the main protease of SARS-CoV-2, but not quite as effectively as the antiviral drug GC376.
Synthetic-Only THC: THC-O Acetate
THC-O acetate is an acetate ester of THC that can be derived from either THC or THCA. It can only be obtained synthetically. Both Delta-8 and Delta-9 varieties of THC-O exist. As research into THC-O is still very limited, little is known about its specific benefits and risks. However, there are a few things that we do know about this lab-made cannabinoid:
When heated, THC-O can let off ketene gas, which is associated with e-cigarette or vaping use-associated lung injury (EVALDI).
THC-O acetate was claimed to offer psychedelic effects similar to LSD or psilocybin, but this has been refuted by a study conducted by the University of Buffalo which found little evidence of THC-O acetate offering psychedelic effects.
In this same study, consumers reported low to moderate levels of cognitive distortions after consuming THC-O acetate, such as difficulties with concentration, short-term memory impairment, and an altered sense of time. In this way, it appears to have some similar side effects to Delta-9 THC.
The Legal Status of THC Isomers, Analogs, and Homologs Around the USA
Marijuana-derived products are currently illegal in the USA under federal law, though individual states can set their own laws regarding the sale and consumption of products containing marijuana and THC. In legal cities like Seattle, Washington, Delta-9 THC products are readily available, along with dozens of strains that have naturally high levels of this psychoactive cannabinoid.
The Farm Bill and Hemp-Derived Cannabinoids
In 2018, the federal Farm Bill legalized hemp and its "derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers." To be classified as hemp, a cannabis plant must contain 0.3% or less of Delta-9 THC by dry weight.
After this bill was passed, hemp manufacturers started producing Delta-8 and Delta-10 THC from hemp-derived CBD and selling it in shops and online. Some states, however—including certain states where marijuana has been legalized—have passed laws explicitly banning the manufacture and sale of these products.
The Legal Status of THC-O Acetate
On February 13, 2023, the DEA responded to a direct inquiry from attorney Rod Kight to clarify that both Delta-8 THC-O and Delta-9 THC-O acetate are federally illegal. Because they are made synthetically in a lab and do not occur naturally in the hemp plant, the DEA explained, the permissions granted in the 2018 Farm Bill do not extend to hemp-derived THC-O.
Where and How to Try Different Types of THC
There are many ways to try the different types of THC with new products appearing on the market all the time. Your local dispensary may stock some of these products, depending on the legality of each type of THC in your state.
Delta-9 THC
Delta-9 THC is the most abundant cannabinoid in most of the strains we stock in our Seattle, WA dispensaries. If you don’t want to smoke cannabis flower, you can try Delta-9 THC in the form of concentrates, vapes, tinctures, and infused edibles and beverages.
Delta-8 and Delta-10 THC
Manufactured Delta-8 and Delta-10 THC are currently illegal in Washington State. In states where the sale of these isomers is allowed, consumers can find them in the form of gummies, tinctures, and vape cartridges.
THCA
THCA is most readily available in unheated products like cannabis juice and tinctures. If your state allows you to grow marijuana at home, you can simply pick a few leaves off the plant and juice them or add them to a smoothie for a healthy and refreshing beverage.
THCV, THCP, and THCB
These minor cannabinoids are most commonly sold and consumed in gummies, tinctures, and vapes. As they only occur in trace amounts in the cannabis plant and research is still in the exploratory phase, these cannabinoids aren’t yet widely available as standalone products in dispensaries.
An Important Note
The delivery method used for a given cannabinoid can drastically change the speed at which you feel the effects of the product; gummies or edibles will likely take a lot longer to take effect than vapes, for example. Start low and go slow the first time you try any new product to avoid getting uncomfortably high.
Experience the THC Family for Yourself
Continued research and innovation in the cannabis industry mean that we’re constantly discovering new compounds in the cannabis plant. The types of THC we’ve covered here are only a few of the many chemicals that work together in synergy to give marijuana its characteristic effects.
If there’s a specific cannabinoid you’d like to try and it’s legal in your state, talk to your local budtender. Dispensary staff members are familiar with the products on offer and the chemical composition of different strains and can help you find the experience you’re looking for.