The Ultimate Guide to THC and All Its Isomers: Delta-9 THC vs Delta-8 THC vs Delta-10 THC vs THC-O vs HHC

Before the 2018 Farm Bill legalized hemp-derived cannabinoids, THC was just THC.

Today, there are so many forms of THC and derivatives of THC available that “THC” can refer to various different compounds.

Generally, what’s meant with THC is delta-9 THC.

Delta-9 THC is the main active compound inside cannabis. It’s the compound that makes you ‘high’. And for some people it’s the compound that can make you experience anxiety or paranoia after smoking cannabis.

So what’s the difference between delta-9 THC and all these new forms of THC?

Well they have the same molecular formula, but are structurally different. All these compounds are THC isomers.

Because of their different structures, they produce slightly different effects.

Today you’re going to learn all the differences and similarities between:

• Delta-9 THC,
• Delta-8 THC,
• Delta-10 THC,
• THC-O, and,
• HHC.

After reading today’s post, you can make an educated cost/benefit analysis about what type of THC will be best for you.

Let’s get started.

Delta- 9 THC Mini-Guide

What Is Delta-9 THC?

Delta-9 THC, or using its full name “delta-9-tetrahydrocannabinol”, is the main active compound of cannabis.

What Are the Effects of Delta-9 THC?

As explained in the introduction, it’s the compound that gets you high.

It can produce a variety of psychoactive effects, some positive ones:

• Relaxation;
• Euphoria;
• Sensory alteration;
• Changes in appetite;
• Changes in perception of time;
• Laughter;
• Clearer thinking;
• Sociability;
• Exaggeration of mood.

But also some negative ones:

• Anxiety;
• Paranoia;
• Depression;
• Hallucinations.

There are currently federally legal delta-9 THC products available, for example: delta-9 THC gummies. And these products will get you high.

What Are The Benefits of Delta-9 THC?

Besides psychoactive effects, delta-9 THC is associated with a variety of health benefits. But also some health risks. It’s the most well-researched cannabinoid in pharmacology.

There are even a few THC-based medicines available for some pain-related conditions. For example, Sativex is a cannabis-based oromucosal spray. It contains THC and CBD in a 1:1 ratio and is used for treatment of neuropathic pain from Multiple Sclerosis (MS) and for intractable cancer pain.

Currently, that’s also one of THC’s main pharmacological use cases:

Pain relief.

Other than pain-reducing properties, THC has (1):

• Anti-inflammatory effects;
• Anti-oxidant and neuroprotective effects, and;
• Nausea-reducing effects.

Although using THC before sleep has been associated with a reduction in REM-sleep, and REM-sleep is thought to be vital in getting restorative sleep, some people with insomnia experience benefits from using THC for sleep (2).

Especially in people where the REM-sleep phase is thought to be problematic, like people with PTSD, THC may provide some relief.

How Does Delta-9 THC Work?

Delta-9 THC is a compound with complex interactions in the human body.

Its psychoactive and part of its pain-reducing effects are attributed to its activation of the CB1 receptor (cannabinoid 1 receptor).

But there are many other receptors delta-9 THC interacts with, including:

• CB2 (cannabinoid 2) receptors;
• PPAR-γ (glitazone) receptors;
• TRPA1 (vanilloid) receptors;
• 5HT3A (serotonin) receptors;
• glycine receptors;
• TRPM8 (cold and menthol) receptors, and;
• TRPV2 (vanilloid) receptors.

Although research about other forms of THC is limited, the fact that they have psychoactive and impairing/intoxicating effects as well makes it likely that these other forms at least activate the CB1 receptor as well.

Delta-8 THC Mini-Guide

What’s Delta-8 THC?

Delta-8 THC, or using its full name “delta-8-tetrahydrocannabinol”, is a cousin of delta-9 THC.

It has a similar molecular structure as delta-9 THC. The only difference is where double bond is located on the chain of carbon atoms:

It does occur naturally in cannabis plants in small concentrations.

These concentrations however are so small that you won’t really feel its effects very noticeably.

If delta-8 THC is so rare in nature…

How come that delta-8 THC products are so plenty?

How Is Delta-8 THC Produced?

Through chemical synthesis, you can isomerize CBD or THC and turn it into different cannabinoids, including delta-8 THC.

Although it’s a chemical process, if done correctly, the result is the same natural delta-8 THC compound found naturally (in small concentrations) inside cannabis plants.

If not done correctly, the product may contain various kinds of potentially harmful chemical residues.

Is Delta-8 THC Safe?

You have to be careful with delta-8 products. Why? Because this chemical process of converting CBD into delta-8 THC can leave a lot of toxic residuals behind.

If you plan to use delta-8 THC, it’s extremely important that you get your products from a brand that provides full panel lab-test reports for their products.

We have reviewed the best delta-8 brands here.

Since various acidic reagents are used in the process of manufacturing delta-8 THC, always make sure that you get your products from a brand that publicizes tests for the following:

• metals,
• pesticides,
• microbes,
• residual solvents, and,
• residual acidic reagents.

This is especially important if you get vape products. Ingesting contaminants orally is less harmful than inhaling them. Your lungs are much more sensitive than your digestive tract.

The truth is, no delta-8 brands test publicize tests for residual acid reagents.

The best available are tests that include everything except residual acidic reagents.

An example of how that looks:

Since no delta-8 brands provide a test for residual acidic reagents, we recommend avoiding delta-8 vape products.

Keep in mind that no studies have been done on the long-term effects of delta-8 THC.

We know that heavy and chronic delta-9 THC use has various health risks, including:

• Impairment of cognitive skills;
• Reduction of gray matter in the hippocampus;
• Increased risk of psychotic disorders (especially if you already have a susceptibility to psychotic illness);
• Increased risk of mood disorders.

And these risks increase the earlier you start using products containing delta-9 THC. Especially if you’re under the age of 18, these risks increase exponentially.

What Are the Effects of Delta-8 THC?

Well, usually it’s experienced as a milder form of delta-9 THC.

But some people experience delta-8 THC as having stronger physical, but milder mental effects than delta-9 THC.

Studies show that delta-8 THC is indeed milder than delta-9 THC as it doesn’t activate the CB1 receptor as potently.

Self-reported use cases for delta-8 THC include (3):

• relief from anxiety and panic attacks,
• relief from stress,
• relief from pain-related conditions.

Some people that experience anxiety and paranoia from delta-9 THC can take delta-8 THC without any issues.

Anecdotal reports show that some people experience stronger effects from delta-8 THC edibles than delta-9 THC edibles.

If delta-8 THC is generally milder than delta-9 THC…

How is this possible?

Well, with edibles, metabolites play an important role in the effects you may experience. Metabolites are compounds that are produced by the metabolization process of your own body, this usually happens in the liver.

A study found that delta-8 and delta-9 THC form different metabolites (4). The main difference was that delta-9 THC produced various epoxyhexahydrocannabinols (EHHC’s) as metabolites. While delta-8 THC produced various dihydroxyhexahydrocannabinols (diOH-HHC) as metabolites.

These metabolites contribute to the effects that you feel from delta-9 or delta-8 THC.

But to feel the effects, your body needs to further metabolize these metabolites as well.

EHHCs are further metabolized by cytochrome P450 liver enzymes.

diOH-HHCs are further metabolized by epoxide hydrolase.

Studies show that some people have deficiencies in cytochrome P450 liver enzymes (5). These people, generally, won’t feel delta-9 THC edibles very well since they have impaired metabolization pathways for this specific compound. But they might feel delta-8 edibles well, because delta-8 gets metabolized by different pathways.

The only way to find out for most people is to either do a liver enzyme test, or experiment with different products.

Delta-10 THC Mini-Guide

What’s Delta-10 THC?

Delta-10 THC is another cousin of delta-9 THC.

The compound appears naturally in cannabis plants, in very small concentrations. But it’s unclear whether the plant directly produces delta-10 THC or whether it’s byproduct of breakdown of other cannabinoids like CBN, for example.

Different epimers of delta-10 THC have been detected in delta-10 THC products.

Epimers are compounds with the same molecular structure, but with one differing chiral center.

While similar, epimers can produce slightly differing effects.

Since most manufacturers don’t really disclose or even know what type of delta-10 THC epimer, or even multiple epimers, is/are inside their products, you never exactly know what you’re ingesting with these products.

How Is Delta-10 THC Produced?

Like with delta-8 THC, through chemical synthesis, you can isomerize CBD or THC and turn it into different cannabinoids, including delta-10 THC.

Although it’s a chemical process, if done correctly, the result is the same natural delta-10 THC compound found naturally (in small concentrations) inside cannabis plants.

Is Delta-10 THC Safe?

Since delta-10 THC products are made with chemicals like acidic reagents and through chemical reactions, it’s extremely important that you only use products that are backed by full panel testing lab reports.

For full transparency, the report should include a test for:

• metals,
• pesticides,
• microbes,
• residual solvents, and,
• residual acid reagents.

This is especially important if you get vape products. Ingesting contaminants is less harmful than inhaling them.

No studies have been done on the safety of delta-10 THC. But assuming that you’re using clean delta-10 THC products, it’s likely that it has similar health risk profile as delta-9 THC.

What Are the Effects of Delta-10 THC?

Cannabinoids produce highly individual effects.

And since delta-10 THC product manufacturers don’t disclose what epimer(s) of delta-10 THC their product contains…

It also explains why people report widely differing effects when using delta-10 THC products, even more so than with other cannabinoid products.

No research has been done on delta-10 THC.

Anecdotal reports show that delta-10 THC is milder than delta-9 THC. Compared to delta-8 THC, some users describe delta-10 THC’s experience as being more mental and less physical.

In cannabis terms, some users describe delta-10 THC’s effects as a Sativa. Meaning energetic and uplifting.

THC-O Mini-Guide

What’s THC-O?

THC- O is the acetate version of THC. It’s a synthetic derivative from THC.

It’s not only produced synthetically. But it’s actually synthetic. It’s not present in cannabis plants naturally.

How Is THC-O Produced?

It’s made legally through a chemical process that involves combining CBD with acetic anhydride.

Is THC-O Safe?

During the manufacturing process, a lot of (toxic) residual compounds can stay inside the end-product.

So with THC-O you have to be very careful that you get your products from a trustworthy brand that provides full-panel lab-test reports for their products.

With THC-O, it’s especially important that the report shows a test for acetate, acetic acid and acetylating agents. If unclear, always ask the manufacturer to show these tests.

There’s little to no research on this synthetic cannabinoid.

We don’t know its long-term effects.

There’s at least one study that shows vaping cannabinoid acetates like THC-O leads to ketene formation (6).

Ketenes are toxic compounds that carry various health risks when inhaled.

What Are the Effects of THC-O?

User reports show that THC-O is more potent than delta-9 THC. Some users even describe the effects as ‘psychedelic’.

A lot of so-called THC-O products contain only between 5% and 20% THC-O. So if you’re interested in trying THC-O, always be aware of the THC-O-percentage.

HHC Mini-Guide

What’s HHC?

HHC (hexahydrocannabinol) is an umbrella term for a set of hydrogenated derivative compounds of delta-9 THC. There are various forms of hexahydrocannabinol.

For example:

There is 9α-OH-HHC, there is 8-OH-iso-HHC. They are similar, but they have a slightly different chemical profile.

Is HHC natural?

I haven’t found any study that listed any form of HHC as a naturally occurring compound inside cannabis. If it’s present naturally at all, it’s in very limited quantities.

Because of this, I would classify HHC as a semi-synthetic cannabinoid.

How is HHC Produced?

Although there are also ways to turn D9-THC into HHCs, it’s highly unlikely that current HHC product producers use D9-THC, since D9-THC is still a schedule 1 drug by the DEA.

It’s fairly certain that current HHC product producers use CBD as a precursor compound to produce HHC products.

Early studies in the 1960s for example, already found that CBD isomerizes into HHCs when it’s combined with acidic reagents (7).

Is HHC Safe?

The process of turning CBD into HHC involves chemical reactions that include acidic reagents that aren’t necessarily safe for human consumption. HHC product producers don’t disclose how they produce their products, so caution is advised.

You could say, for example, that the extraction of CBD also involves chemical compounds like CO2 or ethanol. However, first of all, these are food-safe chemicals, plus the molecular structure of CBD doesn’t change.

Once you change the chemical structure of a natural compound, into a structure that doesn’t exist in nature, you now have a synthetic compound.

And again, although certain sources like Wikipedia claim that HHCs are natural, I haven’t found a single scientific study that listed HHCs as naturally occurring compounds in cannabis plants.

Synthetic compounds aren’t harmful per se, but HHC hasn’t been researched in humans whatsoever.

Other than that, it’s unclear what reagents producers use to convert CBD into HHCs and whether part of those reagents remains in the end-product, therefore I would be very careful with HHC.

Only consume products that are backed by full-panel lab-test reports.

With HHC, it’s especially important that such a report contains an extensive heavy metals test, including:

• Ruthenium,
• Rhodium,
• Platinum,
• Palladium, and,
• Indium.

These are among the most common reagents used in converting CBD to HHC.

What are the effects and benefits of HHC?

HHC products are definitely psychoactive, similar to D9-THC. Some HHC users report that HHC builds up tolerance quicker than other THC-like cannabinoids.

In terms of potential benefits, not much research has been done on HHCs. Some studies have found HHCs or their analogs have anti-tumor activity (8).

Some users who experience anxiety as a side effect from delta-9 THC, report that HHC doesn’t produce any anxiety or paranoia.

Possible side effects of HHC?

There are no scientific studies that looked at the effects of HHC.

Anecdotal reports show that HHC can produce the following side effects:

• Dry mouth,
• Headaches,
• Lethargy,
• Grogginess.

Which THC Isomer is Best for You?

Since cannabinoids have such individualized effects, it’s hard to give general advice.

But the comparison table below should ease your choice:

For more balanced effects, we always recommend combining THC isomers with CBD products, for example CBD oil or capsules.

What’s Next…

Go  to our CBD Hub to learn more about cannabinoid-related topics.

Scientific References:

1. Baron, E. P. (2018). Medicinal Properties of Cannabinoids, Terpenes, and Flavonoids in Cannabis, and Benefits in Migraine, Headache, and Pain: An Update on Current Evidence and Cannabis Science. Headache: The Journal of Head and Face Pain, 58(7), 1139–1186. https://doi.org/10.1111/head.13345
2. Loflin, M. J., Babson, K. A., & Bonn-Miller, M. O. (2017). Cannabinoids as therapeutic for PTSD. Current Opinion in Psychology, 14, 78–83. https://doi.org/10.1016/j.copsyc.2016.12.001
3. Kruger, D. J., & Kruger, J. S. (2021). Consumer Experiences with Delta-8-THC: Medical Use, Pharmaceutical Substitution, and Comparisons with Delta-9-THC. Cannabis and Cannabinoid Research. https://doi.org/10.1089/can.2021.0124
4. YAMAMOTO, I., NARIMATSU, S., SHIMONISHI, T., WATANABE, K., & YOSHIMURA, H. (1984). Difference in epoxides formation and their further metabolism between .DELTA.9-and .DELTA.8-tetrahydrocannabinols by human liver microsomes. Journal of Pharmacobio-Dynamics, 7(4), 254–262. https://doi.org/10.1248/bpb1978.7.254
5. Tomalik-Scharte, D., Maiter, D., Kirchheiner, J., Ivison, H. E., Fuhr, U., & Arlt, W. (2010). Impaired hepatic drug and steroid metabolism in congenital adrenal hyperplasia due to P450 oxidoreductase deficiency. European Journal of Endocrinology, 163(6), 919–924. https://doi.org/10.1530/eje-10-0764
6. Strongin, R., Munger, K., & Jensen, R. (2022). Vaping Cannabinoid Acetates Leads to Ketene Formation. Vaping Cannabinoid Acetates Leads to Ketene Formation. https://doi.org/10.26434/chemrxiv-2022-v379b-v2
7. Gaoni, Y., & Mechoulam, R. (1966). Hashish—VII. Tetrahedron, 22(4), 1481–1488. https://doi.org/10.1016/s0040-4020(01)99446-3
8. Thapa, D., Lee, J. S., Heo, S. W., Lee, Y. R., Kang, K. W., Kwak, M. K., Choi, H. G., & Kim, J. A. (2011). Novel hexahydrocannabinol analogs as potential anti-cancer agents inhibit cell proliferation and tumor angiogenesis. European Journal of Pharmacology, 650(1), 64–71. https://doi.org/10.1016/j.ejphar.2010.09.073