You have heard of CBD; the science is narrower than the shelf space suggests. It does not intoxicate, and its one proven use is a prescription seizure medicine, not the oil at the dispensary counter. For sleep, pain, and everyday calm the human evidence is thin, and CBD is not consequence-free, so this page lays out where it holds up and where it runs out.
Where it stands legally
FDA-approved as prescription Epidiolex (2018) for seizures in Lennox-Gastaut, Dravet, and Tuberous Sclerosis Complex only. No FDA approval for anxiety, sleep, pain, or inflammation. OTC CBD is not FDA-approved for any disease.
Where the evidence stands
Ranked by how much each finding can actually tell you, strongest first. A trial in people outranks a study in cells, including when the answer is no.
Human trial
Reduces seizures in Dravet syndrome (prescription, purified)
Adjunctive purified CBD (20 mg/kg/day) cut convulsive-seizure frequency roughly in half vs placebo. This is prescription Epidiolex in a rare epilepsy, not a dispensary product or an OTC oil. Devinsky O, Cross JH, Laux L, et al. (2017). New England Journal of Medicine, 376:2011–2020. PubMed 28538134
Human trial
Acutely reduced anxiety before a public-speaking stressor
A single 600 mg dose lowered anxiety during a simulated speech. Small (n=24), single-dose, acute: a real signal, not evidence CBD treats an anxiety disorder over time. Later work found an inverted-U dose curve (≈300 mg helped, 900 mg did not). Bergamaschi MM, Queiroz RH, Chagas MH, et al. (2011). Neuropsychopharmacology, 36:1219–1226. PubMed 21307846
Human trial
Blunts some acute effects of THC in the lab
Pre-treatment with pure CBD reduced THC-induced paranoia and memory impairment. Done with isolated compounds at set doses. It does NOT mean the CBD in a real product cancels the high. Englund A, Morrison PD, Nottage J, et al. (2013). Journal of Psychopharmacology, 27:19–27. PubMed 23042808
Human study
Interacts with other medications (CYP450)
CBD raises the active metabolite of clobazam (N-desmethylclobazam), a documented, clinically relevant drug interaction. CBD is not consequence-free, especially for someone taking other medications. Klein P, et al. (per Epidiolex clinical program) (2019). Epilepsy & Behavior, 99:106459. PubMed 31519475
Human study
Raises liver enzymes when combined with valproate
In the pharmaceutical-CBD (Epidiolex) safety program, AST and ALT liver enzymes ran significantly higher in patients also taking valproate, with clinically significant elevations in a small number who normalized after stopping the combination. The same study confirmed CBD raises the active metabolite of clobazam. A real, documented monitoring caution, not a benefit. Gaston TE, Bebin EM, Cutter GR, et al. (2017). Epilepsia, 58:1586–1592. PubMed 28782097
Human study · not established
Relieves chronic pain
The human pain evidence for cannabis is mostly about THC, not CBD. Isolated-CBD trials for chronic pain are weak or null. We do not claim CBD relieves pain.
Human study · not established
Cures insomnia / is a reliable sleep aid
CBD is often sold for sleep, but the controlled human sleep evidence is thin and mixed. We do not present it as a sleep treatment.
Case report
Raised INR in a patient on warfarin (case report)
A single documented patient whose INR rose after CBD was added to warfarin; CBD appears to inhibit the CYP2C9 enzyme that clears warfarin. One case, not a trial, but it is why the honest advice is to monitor INR if someone on warfarin uses CBD. Grayson L, Vines B, Nichol K, et al. (2017). Epilepsy & Behavior Case Reports, 9:10–11. PubMed 29387536
Animal studies · not established
Reduces inflammation in the body
CBD is anti-inflammatory in cell and animal studies. That has not translated into demonstrated anti-inflammatory benefit in people.
No published study · still open
Cancels out THC’s high
CBD can blunt some acute THC effects at set lab doses, but it does not reliably neutralize intoxication in real products. Overstated.
No published study · still open
Store-shelf CBD is the same as the studied CBD
The evidence above is purified, dose-controlled, often prescription CBD. OTC oils vary widely in content and are not the same thing.
Chemical identity, formula and molar mass: PubChem CID 644019, National Center for Biotechnology Information.
Terpenology is educational, not medical advice. Cannabinoid effects are tendencies reported by patients and early research, never guaranteed outcomes. Work with your certifying physician and pharmacist.