La brecha entre lo que el CBD puede hacer y aquello para lo que se vende es amplia. La evidencia sólida es estrecha y específica. El cannabidiol de prescripción purificado, Epidiolex, reduce las convulsiones en tres epilepsias raras en ensayos aleatorizados. Las dosis únicas también reducen la ansiedad aguda en experimentos, a una dosis concreta.
La afirmación popular es que el aceite de CBD de cáñamo de venta libre soluciona de forma fiable el dolor crónico y el sueño. Los datos al respecto son variables y escasos. El mercado de consumo añade tres problemas, cada uno digno de conocer antes de confiar en un producto de venta minorista. Las etiquetas pueden no reflejar el contenido real, algunos productos llevan THC, y ambas formas muestran un riesgo de afectación de enzimas hepáticas e interacciones farmacológicas.
Findings & Outcomes
What It Is
CBD, or cannabidiol, is one of the two main compounds in the cannabis plant. Unlike THC, the other one, it does not make you high. It is sold in two very different forms that often get discussed as if they were the same product:
- Prescription cannabidiol (Epidiolex) is a purified pharmaceutical liquid approved for specific rare epilepsies, made to a known strength and tested in randomized trials.
- Over-the-counter hemp CBD is the oils, gummies, capsules, and creams sold as supplements. It is held to no such manufacturing standard, and it carries almost none of the trial evidence people assume it does.
Almost all of the seizure trials, the anxiety experiments, and the liver-enzyme findings used the purified form at a controlled dose, often far higher than a supplement delivers. A strong result for Epidiolex does not transfer to a retail gummy of uncertain content.
What It Does
At the strong end are three rare epilepsies, where a purified prescription form reduced seizures in randomized trials. In Dravet syndrome, a severe childhood epilepsy, a trial of 120 children cut monthly convulsive seizures by about 39%, against about 13% on placebo. In Lennox-Gastaut syndrome, two trials reduced drop seizures by roughly 42 to 44%, against 17 to 22%. In tuberous sclerosis complex, a trial of 224 patients cut seizures by about 48%, against about 27%. These results made cannabidiol a medicine. They are narrow by design, these specific syndromes, at a controlled dose. They do not show a general sedative or brain-calming effect.
Below that is acute, situational anxiety, on thinner evidence. In small experiments, people took a single dose before a simulated public-speaking test. A 300 mg dose lowered the anxiety spike, while 150 mg and 600 mg did not, an inverted-U where more is not better. This says nothing yet about a daily gummy for an anxiety disorder over months, which has barely been tested. Still, the single-dose signal is an early but real result, worth watching as the research matures.
At the weak end are chronic pain and sleep, the two most-marketed uses. The best systematic review of cannabis-based products rated any pain benefit small, and the CBD-alone data thinner still. For sleep, most of what exists is uncontrolled case reports, and Western trials have not shown a reliable effect.
The Research & Studies
Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.
Seizure Control
Purified CBD cut monthly convulsive seizures about 39% in Dravet syndrome, versus 13% on placebo
In a rigorous trial of children with a severe form of epilepsy, a purified prescription form of CBD cut convulsive seizures by roughly 39%, while placebo cut them by about 13%. This is the strongest and best-established use of cannabidiol.
This double-blind placebo-controlled randomized trial added cannabidiol oral solution (20 mg/kg/day) or placebo to standard antiepileptic treatment. Beyond seizure counts, more participants on cannabidiol were rated improved on a global impression scale. Adverse effects were more common on cannabidiol and included somnolence, diarrhea and raised liver aminotransferases, the last more frequent in those also taking valproate. The result was replicated and underpins the drug's regulatory approval for Dravet syndrome.
Who this may not transfer to:Dravet syndrome affects both sexes and the trial enrolled both; the anticonvulsant effect is not sex-specific.
This is a prescription medicine used under a neurologist for a specific rare epilepsy, with liver monitoring and attention to drug interactions, not a reason to expect a retail CBD product to control seizures. The dose is high and the population narrow.
The study · 1
Devinsky et al., Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome · N Engl J Med 2017;376(21):2011-2020
El CBD con receta redujo las crisis de caída un 42 a 44 % en el síndrome de Lennox-Gastaut, frente a un 17 a 22 % con placebo
En dos ensayos sólidos de otra epilepsia infantil rara, el CBD con receta redujo aproximadamente a la mitad las crisis de tipo caída en muchos pacientes, claramente más que el placebo. Este es el segundo uso convulsivo bien establecido.
Ambos ensayos añadieron solución oral de cannabidiol a los fármacos antiepilépticos existentes en pacientes con síndrome de Lennox-Gastaut. La dosis de 10 mg/kg en el ensayo de Devinsky funcionó casi tan bien como 20 mg/kg con menos efectos secundarios, sugiriendo que una dosis más baja puede ser suficiente. Al igual que en el síndrome de Dravet, la somnolencia, la disminución del apetito, la diarrea y las enzimas hepáticas elevadas fueron los efectos adversos notables, y las elevaciones de enzimas hepáticas fueron más comunes con el valproato concomitante.
Who this may not transfer to:Both trials enrolled both sexes and the anticonvulsant effect is not sex-specific.
Al igual que el resultado en Dravet, este es un uso con receta bajo el cuidado de un especialista con supervisión, y a menudo se prefiere la dosis más baja de 10 mg/kg. No es evidencia a favor del CBD comercial en trastornos convulsivos comunes.
The studies · 2
Devinsky et al., Effect of Cannabidiol on Drop Seizures in the Lennox-Gastaut Syndrome · N Engl J Med 2018;378(20):1888-1897
Thiele et al., Cannabidiol in patients with seizures associated with Lennox-Gastaut syndrome (GWPCARE4) · Lancet 2018;391(10125):1085-1096
El CBD con receta redujo las crisis asociadas a la ETC en aproximadamente un 48 %, frente a un 27 % con placebo
En una tercera epilepsia rara, el complejo de esclerosis tuberosa, el CBD con receta redujo las convulsiones en aproximadamente un 48 % frente a aproximadamente un 27 % con placebo en un ensayo sólido. Es el tercer uso bien establecido para las convulsiones, junto con los síndromes de Dravet y de Lennox-Gastaut.
El ensayo GWPCARE6 añadió solución oral de cannabidiol a 25 o 50 mg/kg/día o placebo a los fármacos antiepilépticos existentes en pacientes de 1 a 65 años con ETC. Ambas dosis de cannabidiol redujeron las crisis significativamente más que el placebo, y se prefirió la dosis más baja de 25 mg/kg/día por su mejor tolerabilidad. Los efectos adversos más comunes fueron diarrea y somnolencia, más frecuentes con la dosis más alta, y se observaron transaminasas hepáticas elevadas en aproximadamente uno de cada cinco con cannabidiol y ninguno con placebo. El resultado respaldó la aprobación del cannabidiol para las crisis asociadas a la ETC.
Who this may not transfer to:The trial enrolled both sexes (about 42% female) and the anticonvulsant effect is not sex-specific.
Al igual que con los resultados en Dravet y Lennox-Gastaut, este es un uso con receta bajo el cuidado de un especialista con supervisión hepática, y generalmente se prefiere la dosis más baja de 25 mg/kg/día. No es evidencia a favor del CBD comercial en trastornos convulsivos comunes.
The study · 1
Thiele et al., Add-on Cannabidiol Treatment for Drug-Resistant Seizures in Tuberous Sclerosis Complex: A Placebo-Controlled Randomized Clinical Trial (GWPCARE6) · JAMA Neurol 2021;78(3):285-292
Anxiety And Stress
Una única dosis de 300 mg de CBD redujo la ansiedad antes de una prueba de hablar en público, mientras que 150 y 600 mg no lo hicieron
Tomar una única dosis moderada de CBD antes de una tarea estresante de hablar en público redujo la ansiedad en pequeños ensayos, con alrededor de 300 mg funcionando mejor que dosis más altas o más bajas. Es un hallazgo temprano y a corto plazo sobre la ansiedad situacional.
Bergamaschi 2011 dio a 24 pacientes con ansiedad social sin tratamiento previo 600 mg de cannabidiol o placebo antes de una prueba simulada de hablar en público y encontró una ansiedad, deterioro cognitivo y malestar reducidos con el fármaco activo. Linares 2019 probó 150, 300 y 600 mg frente a placebo en 57 hombres sanos y encontró que solo 300 mg redujeron significativamente la ansiedad, describiendo una relación dosis-respuesta en U invertida. Estos son experimentos de dosis única y corto plazo en entornos específicos, no ensayos de uso diario para un trastorno de ansiedad.
Who this may not transfer to:The primary social-anxiety trial enrolled both sexes; the confirmatory dose-response study was in men only, so the exact optimal dose in women is less certain.
La evidencia respalda una única dosis moderada antes de un factor estresante específico, no una dosis diaria grande, ya que más no ayudó. Debe situarse junto al tratamiento establecido para un trastorno de ansiedad, no reemplazarlo, y las interacciones farmacológicas deben verificarse primero.
The studies · 2
Bergamaschi et al., Cannabidiol reduces the anxiety induced by simulated public speaking in treatment-naive social phobia patients · Neuropsychopharmacology 2011;36(6):1219-1226
Linares et al., Cannabidiol presents an inverted U-shaped dose-response curve in a simulated public speaking test · Braz J Psychiatry 2019;41(1):9-14
Pain
El CBD por sí solo no alivió claramente el dolor crónico más allá del placebo
A pesar del intenso marketing del CBD para el dolor, la mejor revisión actual encuentra la evidencia débil, con cualquier beneficio pequeño, y los datos del CBD por sí solo demasiado escasos para concluir que alivia de forma fiable el dolor crónico.
La revisión sintetizó ensayos aleatorizados y estudios observacionales de productos a base de cannabis para el dolor crónico. Los productos altos en THC mostraron como mucho pequeños beneficios a corto plazo con efectos secundarios significativos, y el subconjunto de evidencia sobre productos solo de cannabidiol fue escaso, de baja certeza, y no estableció un efecto analgésico claro. Gran parte del argumento popular a favor del CBD para el dolor descansa en trabajo preclínico y testimonios, no en resultados humanos controlados.
Who this may not transfer to:Pooled across mixed-sex chronic-pain populations; CBD-specific subgroups were too small to assess sex differences.
Un lector debe tratar las afirmaciones de CBD para el dolor con cautela: el estante implica un alivio fiable que la evidencia controlada no respalda. Este es un lugar donde la versión popular va muy por delante de la investigación.
The study · 1
Chou et al., Cannabis-Based Products for Chronic Pain: An Updated Systematic Review · Ann Intern Med 2026;179(2):230-241
Sleep
Las puntuaciones de sueño mejoraron para aproximadamente dos tercios de los adultos con CBD en una serie clínica no controlada
El principal informe clínico sobre el CBD y el sueño vio mejorar las puntuaciones de sueño para aproximadamente dos tercios de las personas al principio, pero sin grupo de comparación y con ganancias que iban y venían. Es demasiado escaso para llamar al CBD un remedio para el sueño establecido.
Shannon 2019 revisó historiales de una clínica psiquiátrica donde 72 adultos recibieron CBD (aproximadamente 25 a 175 mg/día) junto con la atención habitual, en su mayoría por ansiedad o mal sueño. Las puntuaciones de ansiedad bajaron y se mantuvieron más bajas en la mayoría de los pacientes; las puntuaciones de sueño mejoraron inicialmente en aproximadamente dos tercios pero fueron más variables mes a mes. Como serie de casos abierta y no controlada, no puede separar un verdadero efecto del CBD del placebo, la regresión a la media, o el efecto colateral de una menor ansiedad.
Who this may not transfer to:Both sexes were included in this uncontrolled clinic series; no sex-specific analysis was possible.
El trabajo de base duradero y gratuito para el sueño hace más por la mayoría de las personas que un suplemento, y el CBD para el sueño debe verse como no confirmado. Si se prueba, corresponde después de lo básico y después de verificar las interacciones farmacológicas.
The study · 1
Shannon et al., Cannabidiol in Anxiety and Sleep: A Large Case Series · Perm J 2019;23:18-041
How It Works
Cannabidiol acts in the brain and in the liver. How far each action carries into an effect you would notice is what separates the strong uses from the marketed ones.
Anatomy of the Practice
1In the brain, in epilepsy
Cannabidiol changes how certain neurons fire, partly through targets other than the usual cannabis receptor, and in these three epilepsies this translates into measurably fewer seizures in controlled trials. This is the only use where the mechanism produces a measured clinical benefit.
2In the stress and fear circuits
At a single dose, cannabidiol dampens activity in brain regions tied to the acute anxiety response. That fits the finding that it blunts the spike of anxiety before a stressful event. The response peaks at a moderate dose and falls off at higher ones.
3In the liver
Cannabidiol is broken down by, and also inhibits, several liver enzymes in the CYP450 family. Those enzymes clear many other drugs, so the same activity can strain the liver and shift the blood levels of medicines taken alongside it.
Using CBD Well
Three things govern whether retail CBD does anything for you: the goal, your medicines, and the product's quality.
If you take an anticoagulant, an anti-seizure drug, or any medicine with a narrow safe range, do not start cannabidiol without checking the interaction with a pharmacist or clinician.
Ways to Do It
Match the goal to the evidence first, sort out your medications, then treat product quality as the main filter. In an unregulated market the label may not match the bottle.
The strong evidence is for three rare epilepsies, a medical route. There is early evidence for acute, situational anxiety. For chronic pain and sleep the evidence is weak, so the free basics in the anxiety and insomnia guides are a solid first step.
Cannabidiol acts on the CYP450 liver enzymes that also clear many common drugs, so before starting anything, list what you take and check it with a pharmacist or clinician. This is free, takes one conversation, and prevents most dangerous interactions.
Labels often miss the real content. Buy only products that publish a recent third-party lab test, a Certificate of Analysis. It should show the actual CBD amount and confirm THC is within legal limits, and it is the one document that verifies what is in the bottle.
Isolate is CBD alone. Broad-spectrum adds other hemp compounds but aims to remove THC. Full-spectrum keeps a trace of THC. That is legal below a set limit, but it can still matter for drug testing and for sensitive users. For anyone who must avoid THC entirely, isolate or a THC-free broad-spectrum with a Certificate of Analysis is the safer pick.
The epilepsy trials used 10 to 20 mg per kilogram of body weight a day, hundreds of milligrams for a child. A typical gummy delivers 10 to 25 mg, so a labeled retail dose is a fraction of what the strong evidence tested.
The relevant experiment used a single oral dose around 300 mg, taken before a specific stressor. Treat that as short-term and early, keep it alongside proper care for an anxiety disorder, and re-check interactions first.
The strong seizure evidence is for a prescription product used under a neurologist, for Dravet syndrome, Lennox-Gastaut syndrome or tuberous sclerosis complex. It comes with liver-enzyme monitoring and dose adjustment of any interacting drugs. This is a medical decision made with a specialist, separate from a retail CBD oil.
Go Deeper
- Anxiety: where the early single-dose CBD evidence fits among approaches with a longer track record, and what to build first for an anxiety disorder.
- Insomnia: the durable, free groundwork for sleep, and the practices the evidence supports first.
- Low back pain: a common reason people reach for CBD, and where the controlled pain evidence actually points.
- Interaction checker: test CBD against the prescriptions you take before you start.
The Chinese Medicine View
Chinese medicine has no concept of CBD, and it would be an invention to claim otherwise. The isolated compound does not map onto the tradition. What the tradition holds is a long, cautious relationship with the cannabis plant itself, dosed to the person and the purpose and used sparingly in its potent parts.
The seed, Huo Ma Ren, or fire hemp seed, is a recognized herb. Classed as sweet and neutral, it moistens the intestines and is used gently for dry constipation in the depleted or the elderly. That is a mild, food-like laxative, a different substance from a concentrated cannabinoid extract, and pointing to it does not lend CBD a tradition it lacks. The flowering and resinous parts of the plant were known too, and classical sources treat them warily, warning that in excess they can disturb the spirit and the mind.
Cautions For This Practice
Extra restraintEverything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.
El CBD elevó las enzimas hepáticas por encima de cinco veces lo normal en un tercio de los adultos con 1500 mg al día, más aún con valproato
Watkins 2021 dio a 16 adultos sanos una dosis fija de 1500 mg al día (aproximadamente 20 mg/kg) durante aproximadamente 3.5 semanas; el 44 % (7 de 16) tuvo ALT por encima del límite superior de lo normal y el 31 % (5 de 16) superó cinco veces lo normal, cumpliendo los criterios internacionales de daño hepático inducido por fármacos y llevando a la interrupción, con las enzimas recuperándose al suspender. La dependencia de la dosis proviene de los ensayos de Dravet y Lennox-Gastaut, donde las elevaciones de transaminasas estuvieron entre los efectos adversos más notables y se concentraron en pacientes que también tomaban valproato. La señal fue lo bastante fuerte como para que la monitorización de la función hepática forme parte de la prescripción aprobada.Watkins et al., Cannabidiol and Abnormal Liver Chemistries in Healthy Adults: Results of a Phase I Clinical TrialDevinsky et al., Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome
CBD raised the active clobazam metabolite about 500%, forcing dose cuts in most children
Geffrey 2015 prospectively measured clobazam and N-desmethylclobazam levels in 13 children as cannabidiol was added. Levels of the active metabolite rose by a mean of about 500%, roughly five- to sixfold, via CYP2C19 inhibition, and 10 of 13 children had their clobazam dose lowered to manage sedation and other effects, while seizure control generally improved. This is a small, uncontrolled prospective series but a well-characterized, mechanistically expected interaction.Geffrey et al., Drug-drug interaction between clobazam and cannabidiol in children with refractory epilepsy
CBD raised one patient's warfarin effect, requiring about a 30% dose reduction
Grayson 2018 reported a 44-year-old man with post-stroke epilepsy (Marfan syndrome, mechanical mitral valve replacement), stable on warfarin, whose INR rose progressively as cannabidiol was titrated up, necessitating serial warfarin dose reductions of about 30% overall to keep the INR in range. Warfarin is metabolized largely by CYP2C9, which cannabidiol inhibits, making the interaction mechanistically expected. As a single case it is low-tier, but it is a documented, plausible, and clinically important warning for a drug where overshoot causes bleeding.Grayson et al., An interaction between warfarin and cannabidiol, a case report
Liver strain, especially with valproate
Cannabidiol can raise liver-enzyme readings, a sign of strain on the liver. This showed up clearly enough in the epilepsy trials that liver monitoring is built into prescription use. In a phase I trial, healthy adults given a fixed 1,500 mg a day saw liver enzymes climb. About a third rose above five times the normal limit, meeting the criteria for drug-induced liver injury. The risk climbs higher again when cannabidiol is taken with valproate, an epilepsy drug. If you use cannabidiol at any meaningful dose, particularly alongside other medicines, liver-function testing is a reasonable precaution to raise with your clinician.
Drug interactions through CYP450
Cannabidiol inhibits several CYP450 liver enzymes that clear many common drugs, so it can push their blood levels up. A prospective study in children showed it raised the active form of clobazam, an anti-seizure drug, about fivefold, so most of the children needed their clobazam dose cut. A documented case showed it raised the effect of warfarin, a blood thinner, enough to need about a 30% dose reduction. That kept the INR, a measure of blood-thinning, in its safe range. If you take an anticoagulant, an anti-seizure drug, or any medicine with a narrow safe range, do not start cannabidiol without checking the interaction with a pharmacist or clinician.
Label accuracy and THC contamination
The over-the-counter market is poorly regulated. When 84 online CBD products were tested, fewer than a third were labeled accurately for CBD content, and THC was detectable in about one in five. That means an uncertain dose, plus the chance of an unwanted psychoactive compound that can show up on a drug test.
Pregnancy, breastfeeding and children
Outside the specific prescription use for rare epilepsies under a specialist, cannabidiol has not been shown safe in pregnancy or breastfeeding, and regulators advise against it in those situations. Keep retail CBD products away from children, both for the unknowns and because of the THC and dosing uncertainty.
Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.
Common Questions
Does CBD actually work, or is it hype?
It depends entirely on the use, and lumping the uses together is what feeds the hype. The seizure evidence is genuine and strong. Acute, situational anxiety has early single-dose support. For pain and sleep, the evidence is thin and far behind the marketing. So CBD is neither a cure-all nor a scam: it is a compound with a few well-backed uses and many unconfirmed ones.
Is store-bought CBD the same as the prescription kind?
No, and not only in quality. Epidiolex is a specific FDA-approved seizure medicine, dispensed by prescription and taken under a specialist. You cannot buy it on a shelf, and no retail gummy or oil is that product, whatever the label claims. The trials that built CBD's reputation used that pharmaceutical, and no supplement can claim them.
Can CBD interfere with my medications?
Yes, and it is the caution to take most seriously. Bring your full medication list to a pharmacist, and run it through the interaction checker before you start. An anticoagulant or an anti-seizure drug is where it matters most.
What dose of CBD helps with anxiety?
The experiments point to roughly 300 mg taken once, ahead of a one-off stressor such as public speaking. There is no established dose for daily use, or for an anxiety disorder over time, an area with almost no controlled data. If you try it, treat it as short-term, keep real treatment in place, and clear interactions with a pharmacist first.
Does CBD help you sleep?
The evidence is weak and uncontrolled. In one clinic series of 72 adults given CBD mostly for anxiety or sleep, sleep scores improved for about two-thirds in the first month. The improvement was inconsistent from month to month, and there was no comparison group. Much of it tracked falling anxiety, so whether CBD did anything for sleep itself is unclear. The steadier route is the free groundwork in the insomnia guide; if you still try CBD, check the drug interactions before you start.
Explore Related
Other pages this one connects to, by the evidence they share, the outcomes they touch, and the ground they cover.
All 12 sources on this page independently checked and cross-referenced.
Thomas Dehli, Founder & Editor, Sacred Lotus
Sacred Lotus has published Chinese medicine reference material since 2001. Integrative pages are held to the same standard as the herb and formula library: cite the source, grade the claim at its real strength, and say where the research has not looked. This page is educational and it is not medical advice. Last reviewed and updated August 9, 2026.
Evidence strength
How confidently the research supports a claim. Strength describes the evidence, not our endorsement.