CBD has strong proof for only one use: the prescription drug Epidiolex reduces seizures in three rare forms of epilepsy. For anxiety the evidence is limited, and for arthritis pain, substance use and most other ailments on CBD labels, placebo-controlled trials have been negative or have not been done. CBD is not risk-free: it can raise liver enzymes and interact with other medicines.
Cannabidiol (CBD) is the main non-intoxicating compound in cannabis. Decades ago, breeders selected plants for THC and CBD nearly disappeared from the market. Today it is sold in oils, gummies, creams and drinks with claims covering everything from pain and sleep to cancer. Some of those claims grew from early lab work and patient reports in the 2000s and 2010s. Since then, researchers have run proper trials. This guide sorts the ailments by what those trials show, from strongest to weakest evidence, and explains the safety and quality issues buyers should know about. For background, see our earlier look at whether the CBD hype is justified.
Evidence at a Glance: What CBD Helps
| Claim | Evidence level | Source |
|---|---|---|
| Reduces seizures in Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex | Strong (FDA-approved as Epidiolex) | FDA |
| Reduces anxiety in social anxiety disorder (public speaking test) | Limited | National Academies, 2017 |
| Reduces anxiety across anxiety disorders | Limited, conflicting trials | Coelho et al., 2024 |
| Relieves osteoarthritis or psoriatic arthritis pain | Not supported (trials negative) | Pramhas 2023; Vela 2022 |
| Treats substance use disorders on its own | Not supported | Redonnet et al., 2025 |
| Improves sleep, inflammation, cancer or other conditions | Early or insufficient | NCCIH |
| Can raise liver enzymes, even at consumer doses | Strong (randomized trial) | Florian et al., 2025 |
Epilepsy: The One Proven Use
In 2018 the FDA approved Epidiolex, a purified, pharmaceutical-grade CBD oral solution. According to the FDA, it is approved for seizures associated with Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex in patients age 1 and older. It remains the only FDA-approved CBD product. A 2023 umbrella review in The BMJ rated the evidence that CBD increases the chance of a 50% seizure reduction as high certainty, while noting higher rates of sleepiness, diarrhea and pneumonia.
The doses are large. The Epidiolex label starts at 5 mg per kilogram of body weight a day and goes up to 20 or 25 mg/kg. For a 70 kg (154 lb) adult, 20 mg/kg is 1,400 mg a day. That is many times what is in a typical retail CBD gummy, and patients on it get regular liver tests. Store-bought CBD is not a substitute for prescribed epilepsy treatment. See our epilepsy and cannabis research guide for more.
Anxiety: Some Promise, Limited Proof
The National Academies found limited evidence that CBD improves anxiety symptoms in people with social anxiety disorder, based on a public speaking test. NCCIH notes that the key study involved just 24 people. A 2024 systematic review of 11 randomized trials by Coelho and colleagues found the results often contradicted each other because of different doses and disorders. CBD may reduce anxiety with few side effects, but no product is approved for it and the right dose is unknown.
Pain and Arthritis: Trials Have Disappointed
Arthritis is one of the most common reasons people buy CBD, and it is where recent trials have been most clearly negative. In a 2023 Vienna trial, 600 mg a day of oral CBD did no better than placebo for knee osteoarthritis and caused more side effects. A 2022 Danish trial of 20 to 30 mg a day found no effect on hand osteoarthritis or psoriatic arthritis pain. Evidence that cannabis helps chronic pain mostly involves THC or THC/CBD combinations. In one fibromyalgia study, CBD actually blunted THC’s pain-relieving effect. Full details are in our guides to arthritis and fibromyalgia.
Addiction, Sleep, Inflammation and Cancer
- Substance use disorders. A 2025 umbrella review in Addiction concluded that CBD alone “does not appear to be efficacious” for treating substance use disorders. A THC/CBD spray (nabiximols) did help cannabis withdrawal and cravings.
- Sleep. Many people take CBD for sleep. NCCIH notes that studies of cannabis products often report better sleep but it is uncertain whether the products affected sleep directly. Drowsiness is also a known CBD side effect, which may be part of what people feel.
- Inflammation. CBD reduces inflammation in animal and lab studies, including a well-known 2000 study in arthritic mice. Human trials have not shown the same benefit for inflammatory disease.
- Cancer. Claims that CBD treats cancer come from lab and animal work. No clinical trial has shown CBD treats cancer in people.
- Other conditions. NCCIH sums up research on cannabis and cannabinoids for other conditions as “in its early stages.”
How CBD Works, in Brief
Unlike THC, CBD does not strongly activate the brain’s CB1 receptors, which is why it does not produce a high. Researchers think it acts on other targets, including the serotonin 5-HT1A receptor, and that it can dampen activity at CB1, as a 2024 review summarizes. That may be why it can change how THC behaves. Researchers are still mapping which of these actions matter in people.
Risks and Side Effects
The FDA lists these known risks of CBD:
- Liver injury. In a 2025 FDA-led trial in JAMA Internal Medicine, 201 healthy adults took CBD at 5 mg/kg a day, a dose within the range consumers take, or placebo for four weeks. In the CBD group, 5.6% developed liver enzyme levels more than three times normal; no one on placebo did.
- Drug interactions. CBD can change how other drugs work, potentially causing serious side effects. Blood thinners, seizure medicines and drugs processed by the liver are common concerns.
- Drowsiness, diarrhea, lower appetite and mood changes such as irritability.
- Male fertility. Animal studies show harm to male reproductive health; human effects are unknown.
- Pregnancy and breastfeeding. Effects on the fetus or a breastfed baby are not known. Avoid CBD unless a doctor advises otherwise.
The Quality Problem: What’s in the Bottle
Retail CBD is not reviewed by the FDA for purity or dose. In a 2017 study in JAMA, researchers tested 84 CBD products bought online. Only 31% were accurately labeled; 43% contained more CBD than stated and 26% contained less. THC turned up in 21% of products, which matters for drug tests. To reduce the risk:
- Buy products with a batch-specific certificate of analysis from an independent lab, and check that the batch number matches.
- Be wary of any product claiming to treat or cure a disease.
- In Washington and Oregon, licensed cannabis stores sell lab-tested CBD products. High-CBD strains such as ACDC, Harlequin and Cannatonic are available there; find a store in our Washington or Oregon directories.
The legal market is also changing. A federal law signed in November 2025, H.R. 5371, redefines hemp by total THC and caps finished hemp products at 0.4 milligrams of total THC per container, counting THCA. Under a September 2026 law, H.R. 6500, that cap applies to products with naturally occurring cannabinoids, including CBD products, starting December 11, 2026, while products with cannabinoids the plant cannot naturally produce lose hemp status November 12, 2026; see our federal law guide. CBD itself is not banned, but a full-spectrum product with more than 0.4 milligrams of total THC in the whole container loses federal hemp status on December 11. Read more: THC Drinks and Hemp Gummies After December 11. Law firms such as DLA Piper note this could push many full-spectrum CBD products, which contain trace THC, out of the hemp market. Our federal marijuana law guide tracks the dates.
Talk to Your Doctor
Tell your doctor and pharmacist about any CBD use, especially if you take prescription drugs, have liver disease, are pregnant or are trying to conceive. Ask if you need liver tests, and agree on a clear goal and time limit for any trial. NCCIH puts it simply: do not use cannabis products to postpone seeing a health care provider about a medical problem.
CBD Benefits FAQ
What is CBD proven to help?
Only seizures in Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex, treated with the prescription drug Epidiolex. Evidence for anxiety is limited, and most other claims lack good human trials.
Does CBD work for pain?
The evidence is weak for CBD alone. Placebo-controlled trials in knee osteoarthritis, hand osteoarthritis and psoriatic arthritis found no benefit. Evidence for chronic pain relief mainly involves THC or THC/CBD products.
Is CBD safe to take every day?
Many people tolerate it, but it is not risk-free. A 2025 FDA-led trial found about 1 in 18 healthy adults taking daily CBD developed significant liver enzyme rises within four weeks. It can also interact with other medicines.
Does CBD get you high?
No. CBD does not produce a high on its own. But some products contain more THC than labeled, and a 2017 study found THC in about 1 in 5 CBD products tested.
Can CBD make you fail a drug test?
It can if the product contains THC, which is common in full-spectrum products and sometimes in mislabeled ones. Standard workplace drug tests are designed to detect THC, not CBD.
How much CBD should I take?
There is no established dose outside of Epidiolex, which is prescribed by weight. If you try CBD, start low, increase slowly, stop if there is no benefit after a few weeks, and talk to your doctor about liver monitoring.
For adults 21+ in legal states. General information, not medical advice. Talk to a doctor before using cannabis for a health condition.
