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CBD (Cannabidiol)
A non-intoxicating cannabis compound: strong (prescription, high-dose) evidence for specific seizure disorders, but only promising-to-mixed evidence for the OTC wellness uses (anxiety, pain, sleep), plus notable drug interactions.
What the evidence says
Most CBD studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from high-quality meta-analyses and randomised trials published 1979–2026 with a typical study size of 63 participants.
Based on 456 studies · 57 meta-analyses · 249 RCTs · 60,446 total participants
Confidence
High confidenceBy outcome
15 more outcomes with fewer studies not shown.
Strong RCT/meta-analytic evidence for prescription-dose seizure control, but only promising-to-mixed wellness-dose data for anxiety, pain, and sleep, plus real safety caveats, pulls the overall score to moderate.
441 rigorous studies
251 randomized trials · 57 meta-analyses · 180 systematic reviews
Our evidence rating for CBD is accountable to this entire body of rigorous research indexed in PubMed — not a hand-picked subset.
PubMed · as of Jul 2026
235 trials ongoing or recruiting · 562 completed on ClinicalTrials.gov
204 of the completed trials have posted results
Registered trials show research momentum for CBD, not proof of effect — a registration is a plan, and posted results are sponsor-reported, not peer-reviewed. They are never counted toward the evidence rating above.
Browse these trials on ClinicalTrials.govClinicalTrials.gov · as of Sep 2026
CBD (cannabidiol) is a non-intoxicating compound from cannabis/hemp (it does not cause the 'high' that THC does). Its evidence is sharply two-tiered.
As the prescription drug Epidiolex — at high, weight-based doses — it is FDA-approved and well-proven for rare seizure disorders (Dravet, Lennox-Gastaut, tuberous sclerosis).
As an OTC wellness supplement at much lower doses, the evidence for anxiety is promising but limited, for chronic pain mixed, and for sleep weak (a controlled trial found 150mg nightly no better than placebo on sleep metrics).
Importantly, CBD inhibits liver CYP enzymes (like grapefruit), can raise blood levels of many medications, and is associated with dose-dependent liver-enzyme elevations. OTC products are also poorly regulated, with frequently inaccurate labeled potency.
Indirectly influences CB1/CB2 signaling and raises endocannabinoid (anandamide) tone, affecting stress, pain, and inflammation.
Activates 5-HT1A receptors, a proposed basis for anxiolytic and some analgesic effects.
Acts on TRPV1 and inflammatory pathways implicated in pain and inflammation.
Reduces neuronal excitability (in part via GPR55 and calcium handling) — the basis of its proven anti-seizure effect at prescription doses.
Check with a pharmacist/clinician — CBD has grapefruit-like CYP drug interactions affecting many drugs.
Avoid — safety not established; FDA advises against CBD in pregnancy.
Avoid or use only with monitoring — dose-dependent liver-enzyme risk.
CBD raises clobazam levels via CYP2C19 — increased sedation/toxicity; needs dose adjustment.
CBD can raise warfarin levels (CYP2C9/3A4) — monitor INR closely.
Additive risk of liver-enzyme elevation/hepatotoxicity.
CBD inhibits these enzymes (grapefruit-like), raising drug levels.
Additive sedation/drowsiness.
Tip: Lower dose; avoid with other sedatives; take in the evening
Tip: Reduce dose; take with food
Tip: Monitor
Tip: Avoid high doses and valproate; check liver enzymes if using high-dose long-term
CBD has an evidence score of 5.8/10 — moderate evidence based on 396 indexed studies, including 6 meta-analyses. A non-intoxicating cannabis compound: strong (prescription, high-dose) evidence for specific seizure disorders, but only promising-to-mixed evidence for the OTC wellness uses (anxiety, pain, sleep), plus notable drug interactions. Representative study: PMID 36206805.
The commonly studied dose of CBD is OTC wellness: 10-50mg/day (some anxiety studies used higher acute doses ~300mg); take with a fat-containing meal (increases absorption several-fold). Prescription Epidiolex for epilepsy is dosed by body weight under medical supervision.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
The best time to take CBD is with meals. Take it with food. Taken with a fat-containing meal, which can increase CBD absorption ~4-5x.
CBD should be used with caution — talk to a healthcare provider before taking it. The most commonly reported side effects are somnolence/sedation, fatigue, diarrhea / GI upset, appetite/weight changes. Use caution if any of these apply to you: Concurrent use of CYP3A4/CYP2C19-metabolized drugs (incl. clobazam, some statins, blood thinners) without medical supervision; Liver disease or elevated liver enzymes; Pregnancy and breastfeeding.
PEA
Likely helpsNaturally occurring fatty acid that supports pain relief and reduces inflammation through the endocannabinoid system.
Collagen
Likely helpsHydrolyzed peptides that rebuild skin elasticity, reduce joint pain, and strengthen bone density — results build over 8-12 weeks.
MSM
Mostly mechanism / observationalOrganic sulfur donor for connective tissue repair — reduces joint inflammation and supports post-exercise recovery and flexibility.
Tart Cherry
Likely helpsNatural melatonin and anthocyanin source with modest, fairly consistent small-RCT support for post-exercise recovery and sleep quality, plus uric-acid lowering — effects are real but small and not seen in every trial.
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Reviewed by Dr. Baher Al Hakim · Last reviewed June 2026 · evidence from 456 studies · how we score · editorial policy
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.