Hemp Derived Cannabidiol
Also known as: CBD, hemp-derived cannabidiol, Cannabidiol
Overview
Cannabidiol (CBD) is a major non-psychoactive phytocannabinoid extracted primarily from the Cannabis sativa plant, specifically from hemp varieties. Unlike tetrahydrocannabinol (THC), CBD does not produce intoxicating effects. It is widely used for its potential therapeutic properties, which include reducing seizure frequency in treatment-resistant epilepsy, alleviating pain, reducing anxiety, and supporting cardiovascular health. CBD interacts with the body's endocannabinoid system, as well as other molecular targets like TRPV1 channels and serotonin 5-HT1A receptors, to exert its effects. Research on CBD is extensive, with high-quality evidence supporting its use in epilepsy, leading to FDA approval for specific formulations. While evidence for pain, anxiety, and cardiovascular effects is growing, more high-quality human trials are needed to confirm these benefits. CBD is generally well-tolerated, with a good safety profile, though it's important to consider potential drug interactions.
Benefits
CBD offers several evidence-based benefits, with varying strengths of evidence. It has strong, high-quality evidence for its efficacy in reducing seizure frequency in treatment-resistant epilepsy, particularly in pediatric and adult patients. This has led to FDA approval for a CBD-based medication (Epidiolex). For pain relief, meta-analyses suggest cannabinoids, including CBD, have moderate analgesic effects, with preclinical studies showing significant effect sizes. While human data are less conclusive, they indicate potential benefits, especially in chronic pain populations. CBD also shows promise for anxiety and other neuropsychiatric disorders, with some clinical trials suggesting anxiolytic effects, though more high-quality randomized controlled trials are needed. Preclinical studies indicate CBD may support cardiovascular health by reducing blood pressure and heart rate under stress, but human data are limited and inconclusive. The time course for benefits varies; seizure reduction is typically observed within weeks, while pain and anxiety effects may depend on dosing and duration.
How it works
CBD primarily exerts its effects by indirectly modulating the endocannabinoid system, rather than directly binding with high affinity to CB1 and CB2 receptors like THC. Instead, it influences receptor signaling, ion channels, and neurotransmitter release. Its known molecular targets include TRPV1 channels, which are involved in pain perception, serotonin 5-HT1A receptors, which play a role in mood and anxiety, and adenosine receptors. CBD also modulates intracellular calcium levels. These interactions allow CBD to impact the central nervous system, immune system, and cardiovascular system. Oral bioavailability of CBD is relatively low (6-19%) but can be improved when consumed with lipids, as it is metabolized primarily by liver enzymes CYP3A4 and CYP2C19.
Side effects
CBD is generally well-tolerated and has a good safety profile in clinical trials. Common side effects, occurring in more than 5% of users, include somnolence (drowsiness), diarrhea, decreased appetite, and fatigue. Less common side effects (1-5%) include elevated liver enzymes and nausea. Serious adverse events are rare, occurring in less than 1% of users. A significant consideration is CBD's potential for drug interactions, as it inhibits CYP450 enzymes, which are crucial for metabolizing many other medications. This can affect the metabolism of drugs such as antiepileptics, leading to altered drug levels. Caution is advised for patients with pre-existing liver impairment, and liver function monitoring is recommended, especially in pediatric epilepsy patients. There is insufficient safety data for CBD use during pregnancy and breastfeeding, so it is generally contraindicated in these populations.
Dosage
The optimal dosage of CBD varies significantly depending on the indication and individual response. For epilepsy, clinical trials have used doses ranging from 5 to 20 mg/kg/day, with 10-20 mg/kg/day being a common optimal range. For anxiety and pain, lower doses, typically ranging from 300 to 600 mg/day, have been explored. The maximum safe dose observed in epilepsy trials is up to 20 mg/kg/day, though higher doses have been studied with an increased incidence of side effects. To maintain consistent plasma levels, CBD is often administered in divided doses throughout the day. Oral administration with food is recommended, as fatty meals significantly enhance its absorption and bioavailability. Purified CBD oil or capsules are preferred for consistent and accurate dosing. No specific cofactors are established as necessary for CBD's efficacy, but monitoring liver enzymes is recommended, particularly at higher doses or with prolonged use.
FAQs
Is hemp-derived CBD psychoactive?
No, hemp-derived CBD is not psychoactive. It does not produce the intoxicating 'high' associated with THC, another cannabinoid found in cannabis.
How soon will effects be noticed?
The time to notice effects varies. For seizure reduction in epilepsy, effects may be observed within weeks. For pain and anxiety, the onset of effects can vary depending on the individual, dosage, and duration of use.
Is CBD safe long-term?
CBD is generally considered safe for long-term use, but monitoring liver function is advised, especially with higher doses or in individuals with pre-existing liver conditions.
Can CBD interact with other medications?
Yes, CBD can interact with other medications, particularly those metabolized by CYP450 enzymes in the liver. It's crucial to consult a healthcare professional if you are taking other medications.
Does CBD cause addiction?
There is no evidence to suggest that CBD causes addiction. It does not produce the euphoric effects or withdrawal symptoms typically associated with addictive substances.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7608221/ – This systematic review and meta-analysis of randomized controlled trials (RCTs) on CBD's adverse effects found that CBD is generally safe but is associated with an increased likelihood of certain side effects, such as somnolence and diarrhea. The study concluded that serious adverse events are rare and the overall risk of bias in most included studies was low, despite some heterogeneity in dosing and populations.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8216112/ – This systematic review and meta-analysis investigated the analgesic effects of cannabinoids, including CBD, primarily in preclinical studies. It reported a significant analgesic effect size, suggesting potential for pain relief. While the review highlighted the need for more clinical trials, it indicated that publication bias was unlikely in the preclinical data, providing strong support for further research.
- https://jamanetwork.com/journals/jama/fullarticle/2338251 – This systematic review and meta-analysis of 79 trials on cannabinoids for medical use suggested improvements in pain and other symptoms, though many individual studies lacked statistical significance. The review found the safety profile of cannabinoids, including CBD, to be acceptable, but noted high heterogeneity and risk of bias in some of the included studies, indicating a need for more consistent research.
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2017.00081/full – This systematic review and meta-analysis focused on the effects of CBD on hemodynamics, primarily using animal studies. It found that CBD may improve cardiovascular parameters under pathological conditions, such as reducing blood pressure and heart rate. However, the review emphasized that human data are limited and predominantly preclinical, necessitating more human trials to confirm these cardiovascular benefits.
