Δ⁸-THC (Tetrahydrocannabinol)

(6aR,10aR)-6,6,9-trimethyl-3-pentyl-6a,7,10,10a-tetrahydrobenzo[c]chromen-1-ol

Overview

Δ⁸-THC (Tetrahydrocannabinol) belongs to Cannabinoids.

Key safety note: Δ⁸-THC is intoxicating and impairs coordination, reaction time and judgement, it is unsafe to drive or operate machinery after use, and high doses can cause anxiety, panic, rapid heart rate, vomiting and occasionally transient psychosis, much like Δ⁹-THC.[2][3]
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology, mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or desirable outcomes.
  • Δ⁸-THC produces a cannabis-like intoxication, mild euphoria, relaxation, altered perception and appetite stimulation, that users commonly describe as clearer-headed and less anxiety-provoking than Δ⁹-THC, though this milder reputation rests largely on user and marketing reports rather than controlled clinical comparisons.
  • Because it is roughly half as potent as Δ⁹-THC, comparable effects need a larger dose. It still impairs memory, coordination and driving ability.
  • Onset and duration depend on route: inhaled effects begin within minutes, while edibles are delayed (roughly 30–120 minutes) and longer-lasting, but reliable Δ⁸-specific timing data are limited, and impure or mislabelled products make real-world effects unpredictable.
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a “safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start low, go slow, wait for full effects before redosing, and never assume an unknown product matches these figures. Missing data is not evidence of safety.

Not reported

Dose ranges

Duration

Chemical & Physical Properties
FormulaC21H30O2
Molar mass314.5 g/mol
StateNot reported
Melting pointNot reported
Boiling pointNot reported
DensityNot reported
Vapor pressureNot reported
pKaNot reported
LogP5.7 (predicted, XLogP3)
SolubilityNot reported
Refractive indexNot reported
Identifiers & Synonyms
CAS5957-75-5
CAS (enantiomer)
PubChem CID638026
InChIKeyHCAWPGARWVBULJ-IAGOWNOFSA-N
InChIInChI=1S/C21H30O2/c1-5-6-7-8-15-12-18(22)20-16-11-14(2)9-10-17(16)21(3,4)23-19(20)13-15/h9,12-13,16-17,22H,5-8,10-11H2,1-4H3/t16-,17-/m1/s1
SMILESCCCCCC1=CC(=C2[C@@H]3CC(=CC[C@H]3C(OC2=C1)(C)C)C)O

Synonyms

  • Delta-8-THC
  • Δ⁸-THC
  • Delta-8-tetrahydrocannabinol
  • Δ⁸-tetrahydrocannabinol
  • Δ⁶-THC (older nomenclature)
Pharmacodynamics & Biochemistry

Δ⁸-THC is a psychoactive cannabinoid and a positional isomer of Δ⁹-THC (the main intoxicant in cannabis): the two share the formula C₂₁H₃₀O₂ and differ only in the position of one ring double bond: the 8,9-position in Δ⁸ rather than the 9,10-position in Δ⁹. That small change makes Δ⁸-THC more chemically stable (longer shelf life, resists oxidation to cannabinol) and slightly less potent. Like Δ⁹-THC it acts as a partial agonist at the CB1 and CB2 cannabinoid receptors with similar intrinsic efficacy, but it binds human CB1 more weakly, reported Ki ≈ 78 nM (range ~28–250 nM across studies) versus ~18–32 nM for Δ⁹-THC, while its human CB2 affinity is comparable (Ki ≈ 12 nM). The Δ8:Δ9 affinity gap is large at human receptors (about 6-fold) but nearly absent in mouse tissue, and overall Δ⁸-THC is roughly half as potent as Δ⁹-THC on most functional and behavioural measures: it produces qualitatively similar but generally milder intoxication and needs a larger dose for a comparable effect. CB1 activation in the brain accounts for its psychoactivity. It occurs only in trace amounts in the cannabis plant. Almost all commercial Δ⁸-THC is semi-synthetic, made by acid-catalysed isomerisation of hemp-derived CBD, and the crude reaction mixture typically contains other cannabinoids and unidentified by-products, so most products sold as 'Δ⁸-THC' are not pure Δ⁸-THC.

Biological targets

  • CB1
  • CB2

Binding & functional measurements

TargetMeasurementSpecies
CB1 receptorKi 36 nMHuman
CB2 receptorKi 50 nMHuman
CB1 receptorEC50 5,820 nMHuman
CB2 receptorEC50 524 nMHuman
Pharmacokinetics
BioavailabilityNot reported
TmaxNot reported
Half-lifeNot reported
VdNot reported
Protein bindingNot reported
MetabolismHepatic: CYP2C9/CYP3A4 oxidation to the active metabolite 11-hydroxy-Δ⁸-THC, then to 11-nor-Δ⁸-THC-9-carboxylic acid
ExcretionRenal, largely as the glucuronide of the 9-carboxylic acid metabolite
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual health factors. Missing harms should never be interpreted as evidence of safety.

Not reported

Δ⁸-THC is intoxicating and impairs coordination, reaction time and judgement, it is unsafe to drive or operate machinery after use, and high doses can cause anxiety, panic, rapid heart rate, vomiting and occasionally transient psychosis, much like Δ⁹-THC. The larger and less-understood hazard is product quality: because it is almost always made by isomerising CBD, commercial Δ⁸ products are frequently impure mixtures containing residual reaction catalysts, solvents, heavy metals and unidentified cannabinoid by-products, and are often mislabelled (many contain Δ⁹-THC above legal limits, or far more or less Δ⁸ than stated). US poison centres logged thousands of Δ⁸ exposures in 2021–22, including hospitalisations and paediatric poisonings from edibles, and its long-term safety is unknown.[2][3]

Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status, prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
Interactions & Contraindications

Drug interactions

Alcohol, Benzodiazepines Additive impairment and sedation with alcohol, benzodiazepines and other CNS depressants, worsening coordination and judgement.[2]
Stimulants (amphetamines, cocaine) Like Δ9-THC it can cause tachycardia and raise cardiovascular strain (caution with stimulants or pre-existing heart disease).[2]
CYP3A4 inhibitors (ritonavir, azole antifungals, macrolides, grapefruit) Metabolised by CYP2C9/CYP3A4, so drugs that inhibit or induce those enzymes are plausible interactants.[2]

Contraindications

Usage & Context
  • A minor natural cannabinoid that became a large commercial product in the United States after the 2018 Farm Bill legalised hemp: it is marketed as a 'legal', milder alternative to Δ⁹-THC in vapes, edibles and tinctures, mostly manufactured from hemp-derived CBD.
  • Used recreationally for a cannabis-like high, and sometimes self-reported for relaxation, sleep or nausea, though it has no approved medical use and has not been evaluated by the FDA.
  • Historically important in cannabinoid chemistry: a partial synthesis was reported by Roger Adams in 1941 and a total synthesis by Mechoulam in 1965. Older literature calls it 'Δ⁶-THC'.
Sources & Evidence

Further Information