CBD (cannabidiol) is a major phytocannabinoid found in Cannabis sativa. Unlike THC, CBD is non-intoxicating and does not produce a "high." It has gained massive popularity as a wellness supplement and is the active ingredient in Epidiolex, an FDA-approved medication for certain forms of epilepsy (Dravet syndrome and Lennox-Gastaut syndrome). CBD is widely available as oils, tinctures, edibles, capsules, topicals, and vape products.
Research suggests potential therapeutic benefits for anxiety, chronic pain, inflammation, and seizure disorders, though the quality of evidence varies significantly by condition. The 2018 Farm Bill legalized hemp-derived CBD (containing less than 0.3% THC) at the federal level in the United States, fueling a multi-billion dollar market. However, regulatory oversight remains inconsistent, and product quality varies enormously.
The World Health Organization concluded in 2018 that CBD exhibits no effects indicative of abuse or dependence potential. It does not bind strongly to CB1 or CB2 cannabinoid receptors. Instead, it acts through a complex pharmacology involving serotonin 5-HT1A receptors, TRPV1 vanilloid receptors, GPR55, and allosteric modulation of various other targets.
Safety at a Glance
High Risk- Drug Interactions
- Blood thinners (warfarin)
- Toxicity: Safety Profile CBD has an excellent safety profile according to extensive clinical data and a comprehensive 2018 WHO ...
- Overdose risk: CBD overdose is not life-threatening. There are no confirmed fatal overdoses from CBD in the medi...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Dosage
oral
Duration
oral
Total: 1.5 hrs – 4 hrsHow It Feels
Cannabidiol -- CBD -- is notable for what it does not do as much as for what it does. There is no high, no intoxication, no altered state of consciousness in any conventional sense. What CBD produces instead is a subtle but perceptible shift in the body's baseline -- a quieting, a settling, a modulation of tension and anxiety that operates below the threshold of dramatic subjective experience but above the threshold of placebo.
The onset takes thirty to sixty minutes by oral route, sometimes longer, and its arrival is so subtle that many people miss it entirely on the first attempt. There is no moment of "it's working" -- no switch being thrown, no wave of alteration. Instead, you may notice, retrospectively, that the tension you were carrying in your shoulders has eased. The background anxiety that was coloring your thoughts has reduced its volume. The restless, unsettled quality of your attention has smoothed out slightly, allowing a more focused, less reactive engagement with whatever you are doing.
Physically, the effects are gentle to the point of near-imperceptibility. There may be a mild warmth, a faint relaxation of muscular tension, a subtle easing of whatever chronic discomfort was occupying your attention. There is no dry mouth, no red eyes, no altered coordination, no impairment of any kind. The body continues to function normally; it simply functions with slightly less friction, as though a barely perceptible source of resistance has been removed from the system.
The emotional effects are similarly understated. There is no euphoria, no mood elevation in any dramatic sense. What CBD offers instead is a modest reduction in reactivity -- stressors that would normally provoke a spike of anxiety produce a slightly smaller spike. Irritations that would normally compound through the day lose a fraction of their cumulative weight. The overall emotional tenor of the day is not transformed but gently modulated, the sharp peaks and valleys of mood softened by a few degrees.
Sleep is perhaps where CBD's effects are most noticeable. Taken in the evening, it can produce a subtle improvement in sleep quality that manifests not as dramatic sedation but as a smoother transition into sleep, a reduction in nighttime waking, and a modestly more refreshed feeling on waking. The dreams are unaffected. The sleep architecture is not disrupted. There is simply a quiet optimization of the body's resting state that becomes apparent not in a single night but over the course of consistent use.
The offset is as imperceptible as the onset. There is no comedown, no rebound, no withdrawal of effects. The subtle modulation simply fades, and baseline reasserts itself without any sense of loss or contrast. The overall experience of CBD is one of absence -- the absence of excess tension, the absence of unnecessary anxiety, the absence of the minor inflammatory noise that the body generates in its daily operations. It is not nothing, but it is close to nothing, and its value lies precisely in that restraint.
Subjective Effects
The effects listed below are based on the Subjective Effect Index (SEI), an open research literature based on anecdotal reports and personal analyses. They should be viewed with a healthy degree of skepticism. These effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects.
Physical Effects
Physical(6)
- Diarrhea— Diarrhea is the occurrence of frequent, loose, or watery bowel movements as a side effect of certain...
- Dry mouth— A persistent, uncomfortable reduction in saliva production causing the mouth and throat to feel parc...
- Insomnia— A persistent inability to fall asleep or maintain sleep despite physical tiredness, often characteri...
- Pain relief— A suppression of negative physical sensations such as aches and pains, ranging from dulled awareness...
- Sedation— A state of deep physical and mental calming that manifests as a progressive desire to remain still, ...
- Seizure— Uncontrolled brain electrical activity causing convulsions and loss of consciousness -- a life-threa...
Cognitive & Perceptual Effects
Cognitive(4)
- Anxiety— Intense feelings of apprehension, worry, and dread that can range from a subtle background unease to...
- Irritability— Irritability is a sustained state of emotional reactivity in which the threshold for annoyance, frus...
- Paranoia— Irrational suspicion and belief that others are watching, plotting against, or intending harm toward...
- Psychosis— Psychosis is a serious psychiatric state involving a fundamental break from consensus reality — char...
Pharmacology
The exact mechanism of action of CBD and THC is not currently fully understood. However, it is known that CBD acts on cannabinoid (CB) receptors of the endocannabinoid system, which are found in numerous areas of the body, including the peripheral and central nervous systems (such as the brain)). The endocannabinoid system regulates many physiological responses of the body including pain, memory, appetite, and mood.
More specifically, CB1 receptors can be found within the pain pathways of the brain and spinal cord where they may affect CBD-induced analgesia and anxiolysis, and CB2 receptors have an effect on immune cells, where they may affect CBD-induced anti-inflammatory processes. Allosteric modulators differ from receptor agonists in that they alter the activity of the receptor by binding to a functionally distinct binding site rather than directly to the receptor.
In addition to the well-known activity on CB1 and CB2 receptors, there is further evidence that CBD also activates 5-HT1A/2A/3A serotonergic and TRPV1–2 vanilloid receptors, antagonizes alpha-1 adrenergic and µ-opioid receptors, inhibits synaptosomal uptake of noradrenaline, dopamine, serotonin and gamma-aminobutyric acid (GABA), and cellular uptake of anandamide, acts on mitochondria Ca2+ stores, blocks low-voltage-activated (T-type) Ca2+ channels, stimulates activity of the inhibitory glycine-receptor, and inhibits activity of fatty amide hydrolase (FAAH).
The oral bioavailability of CBD is 13 to 19%, while its bioavailability via inhalation is 11 to 45% (mean 31%). The elimination half-life of CBD is 18–32 hours.
Cannabidiol is metabolized in the liver and intestines by enzymes CYP2C19 and CYP3A4, and UGT1A7, UGT1A9, and UGT2B7 isoforms.
Cannabidiol is currently approved in the United States under the name Epidiolex as a treatment for epilepsy disorders. It should be noted that cannabidiol has been the subject of sensational health claims in the popular media. A 2016 study found that there is only limited high-quality evidence for cannabidiol having any neurological effect in people.
- Research
CBD is under preliminary research for its potential antipsychotic effect, possibly mitigating some of the negative, psychosis-like effects of THC.
- Risks with vaped/smoked CBD
According to clinical studies,well-tolerated and shows little to no toxicity.
In a 2011 literature review, CBD was found to not alter physiological parameters such as heart rate, blood pressure, and body temperature. Moreover, psychological and psychomotor functions are not adversely affected. Chronic use and high doses of up to 1500 mg per day have been repeatedly shown to be well tolerated by humans. As a result, it is considered to have a good safety profile. However, this information should be interpreted cautiously as cannabidiol has been subject to relatively few human studies; further research is needed to fully establish its safety profile.
Commonly reported side effects from prescribed cannabidiol use include tiredness, diarrhea, and changes of appetite and weight. -low abuse potential compared to THC and other recreational substances. Cannabidiol administration does not produce euphoria or other reinforcing effects and there is no evidence that use results in physical or psychological dependence.
Cannabidiol can be an inhibitor of CYP enzymes (including CYP3A4), which are involved in the metabolism of many psychoactive substances. As a result, it has the potential to cause dangerous interactions. Caution is advised when combining cannabidiol with other substances, particularly with higher doses.
Internationally, cannabidiol is not scheduled under the Convention on Psychotropic Substances or any other UN drug treaty.
Australia:** Cannabidiol (in preparations for therapeutic use containing 2 per cent or less of other cannabinoids found in cannabis) was placed in Schedule 4 as a "Prescription Only Medicine OR Prescription Animal Remedy" in 2015. It was previously listed in Schedule 9 as a prohibited substance.
Canada:** Cannabidiol is specifically listed in the Schedule II Controlled Drugs and Substances Act. However, in 2016 Canada’s "Access to Cannabis for Medical Purposes Regulations" came into effect. These regulations improve access to cannabis used for medicinal purposes, including CBD.
Hong Kong: Illegal in Hong Kong since 1st February 2023, punishable by 7 years imprisonment.
New Zealand:** Cannabidiol is a controlled substance in New Zealand. However, by passing the Misuse of Drugs Amendment Regulations 2017 in September 2017, many of the restrictions currently imposed by the regulations are removed since then. The changes will mean that CBD products, where the level of other naturally occurring cannabinoids is less than 2% of the cannabinoid content, will be easier to access for medical use.
Switzerland:** Cannabidiol is not subject to the Narcotics Act in Switzerland because it does not produce a psychoactive effect. It is still subject to standard Swiss legislation.
United Kingdom:** In 2016, the Medicines and Healthcare products Regulatory Agency (MHRA) issued a statement that products containing CBD used for medical purposes are considered as a medicine subject to standard licensing requirements.
United States:** Cannabidiol is legal under the 2018 Farm Bill. The rest of the cannabis plant (anything with more than 0.3% Delta-9-THC) is still under Schedule I of the Controlled Substances Act.
Cannabidiol (Wikipedia)
Cannabidiol (Isomer Design)
Cannabidiol (Drugs-Forum)
Project CBD
Mechoulam, R., Peters, M., Murillo-Rodríguez, E., & Hanuš, L.O. (2007). Cannabidiol--recent advances. Chemistry & Biodiversity, 4 8, 1678-92.
Mechoulam, R., Parker, L. A., & Gallily, R. (2002). Cannabidiol: an overview of some pharmacological aspects. The Journal of Clinical Pharmacology, 42(S1).
Devinsky, O., Cilio, M. R., Cross, H., Fernandez‐Ruiz, J., French, J., Hill, C., ... & Martinez‐Orgado, J. (2014). Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders. Epilepsia, 55(6), 791-802. https://doi.org/0.1111/epi.12631
Detection Methods
Standard Drug Panel Inclusion
Cannabidiol (CBD) is a non-psychoactive cannabinoid that is not directly detected on standard THC immunoassay drug screens. Standard panels target 11-nor-9-carboxy-THC (THC-COOH), the primary metabolite of delta-9-THC, and pure CBD does not metabolize to THC-COOH. However, many commercial CBD products contain trace amounts of THC (up to 0.3% in "full-spectrum" products), which may accumulate with heavy use and potentially trigger a positive THC screen. CBD isolate products should not cause false positives.
Urine Detection
Pure CBD and its metabolites (primarily 7-hydroxy-CBD and CBD-glucuronide) do not trigger positive results on THC immunoassays at standard cutoffs (50 ng/mL screening, 15 ng/mL confirmation). However, high-dose CBD use (greater than 1000 mg/day) with full-spectrum products containing up to 0.3% THC can result in sufficient THC-COOH accumulation to trigger a positive screen. CBD itself is detectable in urine for 2 to 5 days using targeted LC-MS/MS methods.
Blood and Saliva Detection
CBD is detectable in blood for approximately 24 to 48 hours after oral dosing. The half-life varies with route of administration (2 to 5 hours for inhalation, 18 to 32 hours for oral). Oral fluid testing does not target CBD. Any positive THC result from CBD product use would reflect THC contamination rather than CBD itself.
Hair Follicle Detection
CBD can be detected in hair for up to 90 days using targeted LC-MS/MS analysis. Standard THC hair panels will not report CBD. The presence of CBD in hair may be incidentally noted during comprehensive cannabinoid profiling.
Confirmatory Testing
LC-MS/MS can distinguish CBD from THC, their metabolites, and other cannabinoids with complete specificity. This distinction is increasingly requested as CBD products become more prevalent and users seek to demonstrate that positive THC screens resulted from CBD product contamination rather than cannabis use.
Reagent Testing
Standard reagent kits are not designed for cannabinoid identification. Duquenois-Levine reagent (used for cannabis field testing) may react with CBD-containing material, producing the characteristic purple color, but this test is not specific to THC and will produce false positives with CBD. This is relevant in law enforcement contexts where field testing of CBD products may produce misleading results.
Interactions
| Substance | Status | Note |
|---|---|---|
| 1,3-Butanediol | Caution | Cannabis can unpredictably intensify psychedelic effects and increase anxiety |
| 1,4-Butanediol | Caution | Increased sedation and cognitive impairment |
| 1B-LSD | Caution | Cannabis can unpredictably intensify psychedelic effects and increase anxiety |
| 1cP-AL-LAD | Caution | Cannabis can unpredictably intensify psychedelic effects and increase anxiety |
| 1cP-LSD | Caution | Cannabis can unpredictably intensify psychedelic effects and increase anxiety |
History
Cannibidiol was first isolated from Mexican marijuana by Roger Adams and from Indian charas by Alexander Todd, both in 1940. On the basis of chemical degradation and correlation with cannabinol, a general structure was proposed. In 1963, Raphael Mechoulam isolated CBD from Lebanese hashish and established its structure and relative stereochemistry. Its absolute stereochemistry was determined in 1967.
Cannabis contains more than 400 different chemical compounds, of which 61 are considered cannabinoids, a class of compounds that act upon endogenous cannabinoid receptors of the body. CBD accounts for up to 41% of the plant's extract.
Cannabis produces CBD-carboxylic acid through the same metabolic pathway as THC, until the next to last step, where CBDA synthase performs catalysis instead of THCA synthase.
At room temperature, cannabidiol is a colorless crystalline solid. It is practically insoluble in water.
The exact mechanism of action of CBD and THC is not currently fully understood. However, it is known that CBD acts on cannabinoid (CB) receptors of the endocannabinoid system, which are found in numerous areas of the body, including the peripheral and central nervous systems (such as the brain)). The endocannabinoid system regulates many physiological responses of the body including pain, memory, appetite, and mood.
More specifically, CB1 receptors can be found within the pain pathways of the brain and spinal cord where they may affect CBD-induced analgesia and anxiolysis, and CB2 receptors have an effect on immune cells, where they may affect CBD-induced anti-inflammatory processes. Allosteric modulators differ from receptor agonists in that they alter the activity of the receptor by binding to a functionally distinct binding site rather than directly to the receptor.
In addition to the well-known activity on CB1 and CB2 receptors, there is further evidence that CBD also activates 5-HT1A/2A/3A serotonergic and TRPV1–2 vanilloid receptors, antagonizes alpha-1 adrenergic and µ-opioid receptors, inhibits synaptosomal uptake of noradrenaline, dopamine, serotonin and gamma-aminobutyric acid (GABA), and cellular uptake of anandamide, acts on mitochondria Ca2+ stores, blocks low-voltage-activated (T-type) Ca2+ channels, stimulates activity of the inhibitory glycine-receptor, and inhibits activity of fatty amide hydrolase (FAAH).
The oral bioavailability of CBD is 13 to 19%, while its bioavailability via inhalation is 11 to 45% (mean 31%). The elimination half-life of CBD is 18–32 hours.
Cannabidiol is metabolized in the liver and intestines by enzymes CYP2C19 and CYP3A4, and UGT1A7, UGT1A9, and UGT2B7 isoforms.
Cannabidiol is currently approved in the United States under the name Epidiolex as a treatment for epilepsy disorders. It should be noted that cannabidiol has been the subject of sensational health claims in the popular media. A 2016 study found that there is only limited high-quality evidence for cannabidiol having any neurological effect in people.
- Research
CBD is under preliminary research for its potential antipsychotic effect, possibly mitigating some of the negative, psychosis-like effects of THC.
- Risks with vaped/smoked CBD
According to clinical studies,well-tolerated and shows little to no toxicity.
In a 2011 literature review, CBD was found to not alter physiological parameters such as heart rate, blood pressure, and body temperature. Moreover, psychological and psychomotor functions are not adversely affected. Chronic use and high doses of up to 1500 mg per day have been repeatedly shown to be well tolerated by humans. As a result, it is considered to have a good safety profile. However, this information should be interpreted cautiously as cannabidiol has been subject to relatively few human studies; further research is needed to fully establish its safety profile.
Commonly reported side effects from prescribed cannabidiol use include tiredness, diarrhea, and changes of appetite and weight. -low abuse potential compared to THC and other recreational substances. Cannabidiol administration does not produce euphoria or other reinforcing effects and there is no evidence that use results in physical or psychological dependence.
Cannabidiol can be an inhibitor of CYP enzymes (including CYP3A4), which are involved in the metabolism of many psychoactive substances. As a result, it has the potential to cause dangerous interactions. Caution is advised when combining cannabidiol with other substances, particularly with higher doses.
Internationally, cannabidiol is not scheduled under the Convention on Psychotropic Substances or any other UN drug treaty.
Australia:** Cannabidiol (in preparations for therapeutic use containing 2 per cent or less of other cannabinoids found in cannabis) was placed in Schedule 4 as a "Prescription Only Medicine OR Prescription Animal Remedy" in 2015. It was previously listed in Schedule 9 as a prohibited substance.
Canada:** Cannabidiol is specifically listed in the Schedule II Controlled Drugs and Substances Act. However, in 2016 Canada’s "Access to Cannabis for Medical Purposes Regulations" came into effect. These regulations improve access to cannabis used for medicinal purposes, including CBD.
Hong Kong: Illegal in Hong Kong since 1st February 2023, punishable by 7 years imprisonment.
New Zealand:** Cannabidiol is a controlled substance in New Zealand. However, by passing the Misuse of Drugs Amendment Regulations 2017 in September 2017, many of the restrictions currently imposed by the regulations are removed since then. The changes will mean that CBD products, where the level of other naturally occurring cannabinoids is less than 2% of the cannabinoid content, will be easier to access for medical use.
Switzerland:** Cannabidiol is not subject to the Narcotics Act in Switzerland because it does not produce a psychoactive effect. It is still subject to standard Swiss legislation.
United Kingdom:** In 2016, the Medicines and Healthcare products Regulatory Agency (MHRA) issued a statement that products containing CBD used for medical purposes are considered as a medicine subject to standard licensing requirements.
United States:** Cannabidiol is legal under the 2018 Farm Bill. The rest of the cannabis plant (anything with more than 0.3% Delta-9-THC) is still under Schedule I of the Controlled Substances Act.
Cannabidiol (Wikipedia)
Cannabidiol (Isomer Design)
Cannabidiol (Drugs-Forum)
Project CBD
Mechoulam, R., Peters, M., Murillo-Rodríguez, E., & Hanuš, L.O. (2007). Cannabidiol--recent advances. Chemistry & Biodiversity, 4 8, 1678-92.
Mechoulam, R., Parker, L. A., & Gallily, R. (2002). Cannabidiol: an overview of some pharmacological aspects. The Journal of Clinical Pharmacology, 42(S1).
Devinsky, O., Cilio, M. R., Cross, H., Fernandez‐Ruiz, J., French, J., Hill, C., ... & Martinez‐Orgado, J. (2014). Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders. Epilepsia, 55(6), 791-802. https://doi.org/0.1111/epi.12631
Harm Reduction
Dosing
Start with a low dose of 10-25mg and increase gradually over days to weeks. There is no universally agreed-upon therapeutic dose -- clinical trials have used anywhere from 5mg/day to 1500mg/day depending on the condition being studied. For general wellness use, most people settle in the 25-75mg/day range.
Drug Interactions
Be aware of significant drug interactions via CYP3A4 and CYP2C19 inhibition. If you take any prescription medications, especially the following categories, consult a pharmacist or physician before adding CBD:
- Blood thinners (warfarin)
- Anti-seizure medications (clobazam, valproate)
- Benzodiazepines
- Certain antidepressants (SSRIs metabolized by CYP2C19)
- Immunosuppressants
- Statins
- Opioids (may potentiate sedation)
Product Quality
The CBD market is notoriously poorly regulated. Independent lab analyses consistently find:
- Inaccurate labeling -- studies show that 25-70% of CBD products contain significantly more or less CBD than stated on the label
- Undisclosed THC -- some products contain enough THC to produce psychoactive effects or trigger a positive drug test
- Contaminants -- heavy metals, pesticides, mold, and residual solvents have been found in unregulated products
Always look for products with a valid third-party Certificate of Analysis (COA) from an accredited laboratory. The COA should confirm cannabinoid content and test for contaminants.
Full-Spectrum vs. Broad-Spectrum vs. Isolate
- Full-spectrum contains all cannabinoids from the plant, including up to 0.3% THC. May trigger a positive drug test. Some evidence supports an "entourage effect" where multiple cannabinoids work better together
- Broad-spectrum contains multiple cannabinoids but THC has been removed. Lower drug test risk but not zero
- Isolate is pure CBD with no other cannabinoids. Lowest drug test risk. No entourage effect
If you are subject to drug testing, isolate is the safest choice, but even isolate products can contain trace THC due to manufacturing variability.
Vaping Considerations
Vaping CBD carries additional risks beyond CBD itself. Concerns include:
- Vitamin E acetate contamination (linked to EVALI lung injury outbreak in 2019)
- Heating byproducts from carrier oils and thinning agents
- Unknown long-term effects of inhaling vaporized CBD oil
- Unregulated cartridge quality
If choosing to vape, use products from reputable manufacturers with full COAs that include testing for cutting agents.
General Guidance
- Store CBD products in a cool, dark place to prevent degradation
- Effects from oral CBD take 30-90 minutes to onset and last 4-6 hours
- Sublingual administration (held under the tongue) has faster onset than swallowed products
- If using CBD for a medical condition, discuss with your doctor -- it is not a substitute for evidence-based treatment
- Do not drive or operate heavy machinery until you know how CBD affects your alertness, as drowsiness is common
Toxicity & Safety
Safety Profile
CBD has an excellent safety profile according to extensive clinical data and a comprehensive 2018 WHO review. The WHO Expert Committee on Drug Dependence concluded that CBD is "generally well tolerated with a good safety profile." Clinical trials using Epidiolex at doses up to 20 mg/kg/day provide the most rigorous safety data available.
Common Side Effects
At therapeutic and high supplement doses, reported side effects include:
- Drowsiness and sedation -- the most commonly reported effect, especially at higher doses
- Diarrhea and GI disturbance -- dose-dependent, more common above 300mg/day
- Reduced appetite -- observed in clinical trials, particularly in pediatric epilepsy patients
- Fatigue and lethargy -- often accompanies the drowsiness
- Liver enzyme elevation -- AST/ALT increases observed with Epidiolex, particularly at high doses and when co-administered with valproate. The FDA requires liver function monitoring for Epidiolex patients
What CBD Does NOT Cause
It is critical to distinguish CBD from THC and synthetic cannabinoids. CBD does NOT:
- Produce intoxication, euphoria, or a "high"
- Cause cannabis use disorder or dependence
- Trigger psychotic symptoms or paranoia
- Cause amotivational syndrome
- Produce significant cognitive impairment
Overdose Potential
No fatal overdose from CBD has ever been reported in the medical literature. Animal studies suggest the lethal dose is extremely high (over 200 mg/kg IV in monkeys produced no lethality).
Drug-Drug Interactions
This is the most clinically significant safety concern with CBD. CBD is a potent inhibitor of several cytochrome P450 enzymes:
- CYP3A4 inhibition -- can increase blood levels of many common medications including certain statins, calcium channel blockers, immunosuppressants (cyclosporine, tacrolimus), and benzodiazepines
- CYP2C19 inhibition -- can increase levels of clobazam (this interaction is well-documented from Epidiolex trials), certain antidepressants, and proton pump inhibitors
- CYP2C9 inhibition -- may affect warfarin metabolism, potentially increasing bleeding risk
These interactions are dose-dependent and become more clinically relevant at the doses used in medical settings (150-1500mg/day) compared to typical supplement doses (10-50mg/day), but caution is warranted at any dose when combining with medications.
Long-Term Safety
Long-term safety data for supplement-grade CBD products is still limited. Most clinical trial data covers 12-16 weeks. The unregulated nature of most CBD products introduces additional concerns around contaminants, heavy metals, pesticides, residual solvents, and inaccurate labeling.
Addiction Potential
low abuse potential
Overdose Information
CBD overdose is not life-threatening. There are no confirmed fatal overdoses from CBD in the medical literature. Very high doses (well above typical use) may cause:
These symptoms are self-limiting and resolve as CBD is metabolized (half-life of 18-32 hours orally). No specific emergency treatment is typically needed.
Seek medical attention if:
- Severe drowsiness occurs in combination with other sedating medications (potential compounded CNS depression)
- Allergic reaction symptoms appear (rare but possible with carrier oils or other product ingredients)
- You are on medications known to interact with CBD (CYP3A4/CYP2C19 substrates) and experience unusual symptoms
- Symptoms are more severe than expected, which may indicate the product contains undisclosed substances
Tolerance
| Full | Minimal with standard use |
| Half | N/A |
| Zero | N/A |
Cross-tolerances
Legal Status
Internationally, cannabidiol is not scheduled under the Convention on Psychotropic Substances or any other UN drug treaty.
Australia:** Cannabidiol (in preparations for therapeutic use containing 2 per cent or less of other cannabinoids found in cannabis) was placed in Schedule 4 as a "Prescription Only Medicine OR Prescription Animal Remedy" in 2015. It was previously listed in Schedule 9 as a prohibited substance.
Canada:** Cannabidiol is specifically listed in the Schedule II Controlled Drugs and Substances Act. However, in 2016 Canada’s "Access to Cannabis for Medical Purposes Regulations" came into effect. These regulations improve access to cannabis used for medicinal purposes, including CBD.
Hong Kong: Illegal in Hong Kong since 1st February 2023, punishable by 7 years imprisonment.
New Zealand:** Cannabidiol is a controlled substance in New Zealand. However, by passing the Misuse of Drugs Amendment Regulations 2017 in September 2017, many of the restrictions currently imposed by the regulations are removed since then. The changes will mean that CBD products, where the level of other naturally occurring cannabinoids is less than 2% of the cannabinoid content, will be easier to access for medical use.
Switzerland:** Cannabidiol is not subject to the Narcotics Act in Switzerland because it does not produce a psychoactive effect. It is still subject to standard Swiss legislation.
United Kingdom:** In 2016, the Medicines and Healthcare products Regulatory Agency (MHRA) issued a statement that products containing CBD used for medical purposes are considered as a medicine subject to standard licensing requirements.
United States:** Cannabidiol is legal under the 2018 Farm Bill. The rest of the cannabis plant (anything with more than 0.3% Delta-9-THC) is still under Schedule I of the Controlled Substances Act.
Cannabidiol (Wikipedia)
Cannabidiol (Isomer Design)
Cannabidiol (Drugs-Forum)
Project CBD
Mechoulam, R., Peters, M., Murillo-Rodríguez, E., & Hanuš, L.O. (2007). Cannabidiol--recent advances. Chemistry & Biodiversity, 4 8, 1678-92.
Mechoulam, R., Parker, L. A., & Gallily, R. (2002). Cannabidiol: an overview of some pharmacological aspects. The Journal of Clinical Pharmacology, 42(S1).
Devinsky, O., Cilio, M. R., Cross, H., Fernandez‐Ruiz, J., French, J., Hill, C., ... & Martinez‐Orgado, J. (2014). Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders. Epilepsia, 55(6), 791-802. https://doi.org/0.1111/epi.12631
Tips (6)
CBD is a potent inhibitor of CYP3A4 and CYP2C19 liver enzymes. If you take prescription medications -- especially blood thinners, anti-seizure drugs, benzodiazepines, statins, or immunosuppressants -- talk to your pharmacist before adding CBD. It can significantly increase blood levels of these drugs.
Know the difference between full-spectrum, broad-spectrum, and isolate. Full-spectrum contains trace THC (up to 0.3%) and may trigger a drug test positive. Broad-spectrum has THC removed. Isolate is pure CBD only. If drug testing is a concern, isolate is your safest bet, though even isolate products can contain trace THC from manufacturing.
Always check for a third-party Certificate of Analysis (COA) before buying any CBD product. Studies consistently find that 25-70% of CBD products are mislabeled, containing more or less CBD than advertised, and sometimes undisclosed THC. A valid COA from an ISO-accredited lab is the minimum standard.
Start with 10-25mg per day and increase gradually over 1-2 weeks. There is no one-size-fits-all dose for CBD. Clinical trials have used anywhere from 5mg to 1500mg daily depending on the condition. Most people using CBD for general wellness find their sweet spot between 25-75mg/day.
CBD supplements are not regulated as strictly as pharmaceuticals. The FDA does not verify the contents, purity, or safety of CBD products before they hit shelves. This means contaminants (heavy metals, pesticides, residual solvents) and inaccurate potency are real risks. Stick to brands that publish full COAs and have a track record.
If you vape CBD, be aware that the risks go beyond CBD itself. The 2019 EVALI lung injury outbreak was linked to vitamin E acetate used as a cutting agent in vape cartridges. Use only products from reputable brands with COAs that test for cutting agents, and avoid any cartridges with unknown carrier oils.
See Also
References (3)
- PubChem: Cannabidiol
PubChem compound page for Cannabidiol (CID: 644019)
pubchem - Cannabidiol - TripSit Factsheet
TripSit factsheet for Cannabidiol
tripsit - Cannabidiol - Wikipedia
Wikipedia article on Cannabidiol
wikipedia