What Is CBD and What Does It Actually Do? An Evidence Map
One use is proven, a few are promising, most are untested. What the trials show, why doses differ from shop products, and the rules by market.
Key takeaways
- CBD's only proven use is Epidiolex for three seizure disorders.
- Anxiety, sleep and pain evidence is limited or mixed.
- Trial doses run to hundreds of mg a day; UK advice caps food CBD at 10 mg, EFSA at about 2 mg.
- Label accuracy is poor: 74% of 202 US products were off by 10% or more.
Walk into a drugstore in Berlin, a corner shop in Leeds or a gas station in Texas and the CBD bottles say much the same thing: calm, sleep, recovery, balance. Behind those words sits a thin and uneven body of research. One use is proven to regulatory standard. A few more are plausible. Most are simply untested at the doses sold over the counter. This page sorts the claims by the strength of the evidence behind them.
CBD in plain terms
Cannabidiol (CBD)
The second best-known cannabinoid after THC. It does not produce a high at typical doses. In laboratory work, CBD acts as an antagonist of compounds that activate the CB1 and CB2 receptors, the opposite of what THC does there (Pertwee, 2008).
CBD comes mostly from hemp, the low-THC type of cannabis. Products are sold as isolate (CBD only), broad-spectrum (other cannabinoids, THC removed) or full-spectrum (whole-plant extract, which can contain some THC). For how it differs from THC on effects and labels, see CBD vs THC.
The evidence map: proven, promising, unproven
Only rare-epilepsy treatment has passed the full drug-approval process. Everything else below rests on small trials, mixed results or animal work.
| Claim | Best human evidence we found | Where it stands |
|---|---|---|
| Seizures in Dravet, Lennox-Gastaut, TSC | Randomized trials; in Dravet syndrome, median monthly convulsive seizures fell from 12.4 to 5.9 on CBD vs 14.9 to 14.1 on placebo (Devinsky et al., NEJM 2017) | Proven: FDA-approved as Epidiolex for patients 1 year and older |
| Cutting down cannabis use | Phase 2a trial of 82 people: 400 mg and 800 mg CBD met the pre-set efficacy criteria (Freeman et al., Lancet Psychiatry 2020) | Promising: needs larger trials |
| Anxiety | One small study of 24 people with social anxiety found less anxiety in a simulated speech test (NCCIH summary); a 2024 trial in women with breast cancer missed its primary endpoint | Mixed: a 2019 meta-analysis found scarce evidence for cannabinoids in anxiety or depression |
| Sleep | Studies of cannabis products, not CBD alone, in people with MS, PTSD or chronic pain; unclear whether the cannabinoids or symptom relief improved sleep | Unproven |
| Chronic pain | Mostly studies of THC or THC/CBD mixes, not CBD alone | Unproven: the IASP task force (2021) did not endorse cannabinoids for pain |
| Everything else (acne, inflammation, cancer, “balance”) | Mostly lab and animal studies | Claims, not evidence |
Why trial doses don't match the bottle
The seizure results came at doses far above what shop products deliver. Epidiolex starts at 2.5 mg per kg twice a day and can go up to 25 mg per kg a day, according to its US prescribing information.
350–1,750 mg
Epidiolex daily range for a 70 kg adult (5–25 mg/kg)
Epidiolex label, DailyMed 2026
10 mg
UK Food Standards Agency daily limit advice for healthy adults
FSA, October 2023
≈2 mg
EFSA provisional safe level for food supplements, 70 kg adult
EFSA, February 2026
That gap cuts both ways. A 10–25 mg gummy is unlikely to reproduce what trials saw at hundreds of milligrams. But the high doses that worked also caused side effects, including liver-enzyme rises, which is why food regulators set such low limits. The trade-offs are in our CBD side effects guide.
What regulators allow, market by market
CBD's legal status depends on how it is sold: as a medicine, a food or supplement, or a cannabis product. The rules below applied in September 2026.
| Market | How CBD is sold legally | Official position |
|---|---|---|
| United States | Epidiolex by prescription; hemp CBD widely sold, but FDA says CBD cannot be marketed as a dietary supplement or added to food | Hemp redefinition caps finished products at 0.4 mg total THC per container from December 11, 2026 |
| Canada | Only through licensed cannabis retailers or medical sellers; CBD is controlled under the Cannabis Act | Health Canada |
| United Kingdom | As food under novel-food rules; products must stay within the controlled-drug exemption (≤1 mg THC per component) | FSA advises healthy adults to take no more than 10 mg a day |
| Germany, Netherlands and rest of EU | CBD foods need novel-food authorisation; none had been granted | EFSA set a provisional 2 mg/day level in 2026 |
| Australia | Prescription (Schedule 4); pharmacist-only (Schedule 3) allowed up to 150 mg a day for adults, but only for registered products | Poisons Standard |
Local detail matters: see UK, Germany, Netherlands and Australia for country pages. This is general information, not legal advice.
Label accuracy: what you pay for vs what's inside
Independent testing keeps finding that CBD labels are unreliable, which makes any dose advice harder to follow.
- Of 202 US products tested in a 2024 study, 74% were off their labeled CBD content by at least 10% (Gidal et al., Frontiers in Pharmacology).
- Only 54% of 80 products fell within ±10% of the label in a 2022 study (Johnson et al., Journal of Cannabis Research).
- All full-spectrum tinctures in an 18-product 2025 study contained delta-8 and delta-9-THC (Sullivan et al., Cannabis and Cannabinoid Research).
How to judge a CBD claim in 30 seconds
- Named condition, named study — A real claim cites a trial in humans, not “research shows”.
- Dose in milligrams per serving — Without it you cannot compare the product with any study.
- Batch-matched lab report — Check CBD, THC and contaminants; here is how to read one.
- No disease cures — Promises to treat anxiety, cancer or arthritis are a red flag in every market above.
- Your medicines — CBD interacts with several drugs; ask a pharmacist first.
FAQ
What does CBD stand for?
CBD stands for cannabidiol, one of more than 100 cannabinoids in the cannabis plant. It is usually extracted from hemp.
Does CBD get you high?
No, not at typical doses. Full-spectrum products can contain small amounts of THC, though, which can matter for drug tests and for sensitive people.
What is CBD proven to help with?
Regulators have approved CBD only for seizures linked to Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex, as the prescription drug Epidiolex. Other uses are still under study.
Does CBD help with anxiety?
Evidence is limited. A small study found CBD reduced anxiety during a simulated public-speaking test, but a 2019 meta-analysis found scarce evidence overall and a 2024 trial missed its main goal.
How much CBD should I take?
There is no evidence-based dose for general wellness. The UK Food Standards Agency advises healthy adults to stay at or below 10 mg a day from food, and EFSA's provisional level is about 2 mg; talk to a doctor if you take other medicines.
Sources
- DailyMed, US National Library of Medicine — Epidiolex (cannabidiol) oral solution — prescribing information · checked May 2026
- New England Journal of Medicine — Trial of cannabidiol for drug-resistant seizures in the Dravet syndrome (Devinsky et al.) · 2017
- The Lancet Psychiatry — Cannabidiol for the treatment of cannabis use disorder: a phase 2a randomised trial (Freeman et al.) · 2020
- NCCIH, National Institutes of Health — Cannabis (marijuana) and cannabinoids: what you need to know · checked Nov 2019
- The Lancet Psychiatry — Cannabinoids for the treatment of mental disorders: a systematic review and meta-analysis (Black et al.) · 2019
- JAMA Network Open — Cannabidiol for scan-related anxiety in women with advanced breast cancer (Nayak et al.) · 2024
- Pain — IASP Presidential Task Force on Cannabis and Cannabinoid Analgesia position statement · 2021
- British Journal of Pharmacology — The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids (Pertwee) · 2008
- US Food and Drug Administration — FDA regulation of cannabis and cannabis-derived products, including CBD · checked Jul 2024
- Health Canada — Cannabidiol (CBD) and industrial hemp · checked Jul 2020
- Food Standards Agency — FSA updates consumer advice for CBD · checked Oct 2023
- EFSA Journal — Update of the statement on safety of cannabidiol as a novel food · checked Feb 2026
- Landtag Nordrhein-Westfalen — Antwort der Landesregierung: Wie bewertet die Landesregierung die Nutzung von Cannabidiol? (Drucksache 18/9502) · checked Jun 2024
- Therapeutic Goods Administration (via FAOLEX) — Therapeutic Goods (Poisons Standard—June 2024) Instrument 2024 · checked May 2024
- Frontiers in Pharmacology — Product labeling accuracy and contamination analysis of commercially available cannabidiol product samples (Gidal et al.) · 2024
- Journal of Cannabis Research — Label accuracy of unregulated cannabidiol (CBD) products (Johnson et al.) · 2022
- Cannabis and Cannabinoid Research — Label accuracy of CBD and THC in commercial CBD tinctures from the United States (Sullivan et al.) · 2025
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