What Is THCB? Everything You Need to Know

THCB is a rare minor cannabinoid and a homologue of delta-9 THC which was originally discovered in 1976. Like delta-9, THCB is naturally present in all forms of cannabis and induces an intoxicating euphoric high.  

Research suggests that THCB has a stronger binding affinity at cannabinoid 1 (CB1) receptors and almost equal binding affinity at cannabinoid 2 (CB2) receptors than delta-9. Researchers used biochemistry tests to determine that THCB is about three times more active at the CB1 receptor than classic delta-9 THC. 

THCB’s potential benefits include pain relief and anti-inflammatory effects. Due to its similarity to delta-9, it might have other benefits such as sleep promotion, appetite stimulation, anti-proliferation, antianxiety, and stress relief. 

What Is THCB?

THCB, also known as Δ9-tetrahydrocannabutol, butyl-delta-9-THC, or tetrahydrocannabinol-C4, is a rare minor cannabinoid naturally found in all varieties of cannabis, including hemp and marijuana. Rare, “minor” cannabinoid means it makes up to 1% of a cannabis plant’s total cannabinoid profile. 

Not much is known about THCB, especially when compared to delta-8 THC, HHC and other THC isomers. However, current research suggests THCB is a possible anti-inflammatory and pain reliever. 

THCB has the chemical formula C20H28O2 and is a homologue of delta-9, meaning it has an almost identical molecular structure except for its side chain. Delta-9 has a 5-carbon side chain comprising five carbon atoms, while THCB only has four. This side chain difference is relevant. Studies show the higher the number of carbon atoms in a side chain, the better the cannabinoid is at binding to cannabinoid receptors. In theory, THCB should be a weaker receptor agonist, but studies suggest it has stronger CB1 receptor binding affinity than delta-9 (up to three times stronger). 

THCB was first identified in 1976 at Oxford University. It was confirmed alongside CBNB (butyl-cannabinol), CBDB (butyl-cannabidiol), and THCBA (butyl-tetrahydrocannanolic acid) using early GC/MS technology.

Recently, a team of Italian researchers — led by Professor Giuseppe Cannazza of the University of Modena — further characterized THCB by itself and in a related paper along with THCP and CBDP, both in 2019. The team analyzed the natural cannabis sample FM2 provided by The Military Chemical Institute using advanced mass-spectrometry and liquid chromatography technology. 

FM2 is a special type of cannabis. It produces flowers with up to 10% THC and 12% CBD, offering a balanced euphoric high with pain-relieving and anti-inflammatory benefits. Counterintuitively, the Italian researchers predict that FM2 has more THCB and other butyl homologues than FM1, its THC-dominant counterpart.

Scientific Research on THCB Is Limited

Research on THCB is very limited and not conclusive. No clinical studies on THCB’s pharmacological activity in humans exist. 

Only one mouse study exists to evaluate its biological properties. Mice were subjected to a classic tetrad test for CB-like (cannabimimetic) assessment. The study shows that THCB is an analgesic and anti-inflammatory in mice test subjects, possibly resulting from CB1 receptor activity.

The preclinical study shows THCB interacts with your endocannabinoid system, specifically cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2), at an affinity of Ki 15 nM and 51 nm, respectively. The smaller the Ki number, the better the compound is at binding to cannabinoid receptors. 

By comparison, delta-9’s binding power at CB1 is roughly Ki 40 nM and THCV 75 nM. These Ki values suggest that THCB potentially induces a stronger and more pronounced high. With CB2 activity at comparable levels to THC, roughly equivalent anti-inflammatory activity is reasonably predicted. 

What Are the Benefits of THCB?

Beyond reducing pain and inflammation, THCB’s other benefits are purely speculative. Since it’s a homologue of delta-9 with a similar molecular structure but a stronger binding affinity at CB1 receptors, we can theorize that THCB has similar benefits to delta-9 with added potency.

However, this theory has not been proven in any clinical literature, nor is it widely accepted as conclusive. 

Delta-9’s potential benefits include:

• Pain relief and anti-inflammation
• Anti-anxiety and depression (low doses) 
• Anti-proliferation
• Anti-glaucoma and ocular eye pressure relief 
• Increased appetite (for eating disorders)
• General health and wellness

Remember: THCB is potentially up to three times more potent than delta-9 THC. Users are recommended to dose it carefully and not consume the same quantity as they would with delta-9 THC. 

Effects: Does THCB Get You High?

Like almost all delta-9 homologues, THCB makes you feel high with moderate euphoria, relaxation and mental and physical calm. The euphoric high is similarly potent as its sibling THC isomers such as HHC or THC-O, but it’s enough for beginner or casual cannabis users at lower doses, or experienced users requiring noticeable effects.  

Other THCB effects can include:

• Sedation 
• Focus
• Concentration 
• Sleep-promotion
• Appetite stimulation 

Possible THCB side effects include:

• Red eyes
• Dry mouth and eyes
• Physical discomfort
• Cognitive, memory, and learning impairment 
• Paranoia
• Anxiety or dysphoria
• Nausea and vomiting

THCV vs. CBD: Key Differences

• THCB and CBD are practically opposites. CBD is a non-intoxicating cannabis compound and does not induce a euphoric high thanks to its low-to-non-existent binding affinity with CB1 receptors. Instead, it may increase endocannabinoid tone by inhibiting an ECS enzyme, FAAH.
• CBD interacts with other receptors, including the TRPV family for pain relief and 5-HT (serotonin) for anti-anxiety and antidepressant effects. Whether THCB interacts with these receptors or ECS enzymes like FAAH is currently unknown. 
• CBD is also not a rare minor cannabinoid like THCB. Some cannabis cultivars are specially grown to contain up to 25% CBD (12-15% average for type III chemovars like FM2).

Conclusion

THCB isn’t a revolutionary cannabinoid, but does it have to be? It’s a very promising cannabinoid that could suit beginner users needing a moderately intense euphoric high without overwhelming side effects. 

However, as with any THC isomer, it’s best to start low and go slow. Always dose lower than usual, and don’t take too much in one go.

Last medically reviewed on November 1, 2023.