Delta-8-THC: What It Is, Effects and Safety | PatientsCann UK

Delta-8-THC

delta-8-THC, delta eight

pronounced: DEL-tuh ate tet-ruh-hy-droh-kuh-NAB-ih-nol

A close cousin of THC with the double bond in a different place - usually milder.

Neutral cannabinoidFormula: C21H30O2Intoxicating: Yes
Type
Neutral
Formula
C21H30O2
Intoxicating
Yes
Key focus
Milder high

Delta-8-tetrahydrocannabinol · 314.5 g/mol

The molecule

Chemical structure

This is the accurate skeletal structure of Delta-8-THC, drawn from PubChem data. Each corner and line-end is a carbon atom, and the red O marks oxygen. Its formula is C21H30O2 and it weighs 314.5 g/mol.

Milder highAnti-sicknessPain reliefAppetite

About

What is Delta-8-THC?

Delta-8-THC is a close relative of ordinary delta-9-THC. The two molecules are almost identical; the only difference is where one double bond sits in the ring. That tiny change is enough to make delta-8 behave a little differently.

It occurs naturally in cannabis only in very small amounts. Most delta-8 sold abroad is made in a lab from CBD, which is a very different thing from a plant extract.

In the body

How 8-THC Works

Delta-8 switches on the same CB1 receptor as delta-9-THC, so it is intoxicating, but it holds on a little less tightly. Many people describe its effects as milder and clearer-headed, with less anxiety, though this varies from person to person.

It is also more chemically stable than delta-9-THC, meaning it breaks down more slowly. Research on delta-8 in people is limited compared with delta-9-THC.

Receptor snapshot

Where 8-THC Acts

The endocannabinoid system has two main receptors. Here is how strongly Delta-8-THC acts on each.

CB1Brain & nervous system
Partial

Switches on CB1 like Delta-9-THC, but holds on a little less tightly, so the effects are usually milder.

CB2Immune system & body
Partial

Also binds CB2.

In the plant

How 8-THC is Made

In the plant, only a trace of delta-8 forms, partly as delta-9-THC slowly degrades.

Because there is so little of it naturally, commercial delta-8 is usually made in a lab by converting CBD. This is why product quality and purity matter so much.

Comes fromDelta-9-THC→ add heat →Delta-8-THC

Good to know

Safety and Side Effects

Delta-8 can cause the same kinds of effects as THC, including a fast heartbeat, dry mouth and drowsiness, and it affects driving. A bigger concern is quality: lab-made delta-8 products, especially unregulated ones, can contain leftover chemicals and unknown by-products.

In the UK, delta-8-THC is a controlled substance, the same as delta-9-THC. Only use cannabinoids from a regulated, prescribed source.

Questions

Delta-8-THC: Common Questions

Is delta-8-THC the same as normal THC?
Almost. Delta-8 and delta-9-THC differ only by where one double bond sits in the ring. That small change makes delta-8 bind the CB1 receptor a little less tightly, so its effects are usually milder.
Is delta-8-THC legal in the UK?
Delta-8-THC is a controlled substance in the UK, the same as delta-9-THC. Much of what is sold abroad as "delta-8" is made in a lab, not from the plant.
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Important: This page is for education only. It is not medical advice. Cannabinoid research is still developing, and many studies have been done in cells or animals rather than people. Always speak to your prescriber before changing your treatment. PatientsCann UK does not recommend any specific cannabis product.

References

  1. Kruger, D.J. and Kruger, J.S. (2022) 'Consumer experiences with delta-8-THC: medical use, pharmaceutical substitution, and comparisons with delta-9-THC', Cannabis and Cannabinoid Research, 7(6), pp. 866-876. doi: 10.1089/can.2021.0124.
  2. ElSohly, M.A. and Gul, W. (2014) 'Constituents of Cannabis sativa', in Pertwee, R. (ed.) Handbook of Cannabis. Oxford: Oxford University Press, pp. 3-22.
  3. Pertwee, R.G. (2008) 'The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta-9-tetrahydrocannabinol, cannabidiol and delta-9-tetrahydrocannabivarin', British Journal of Pharmacology, 153(2), pp. 199-215. doi: 10.1038/sj.bjp.0707442.
  4. National Center for Biotechnology Information (2025) PubChem Compound Database. Bethesda: U.S. National Library of Medicine. Available at: https://pubchem.ncbi.nlm.nih.gov (Accessed: 29 July 2026).