CBD or Cannabidiol oil – a chemical compound found in the Cannabis Sativa plants – has gained much popularity as a therapeutic drug among people seeking alternative treatment for various kinds of physical and mental health issues. Recent studies have revealed quite a few of its benefits and presented evidence of its potential as a much safer option over many pharmaceutical drugs.
However, there is still a lot to be desired as far research on this non-psychoactive (*1) cannabinoid (*2) is concerned. Due to the lack of extensive study on its side effects, it is often not advised by doctors even in places where medical marijuana is legal.
In spite of its benefits, this herbal extract, like everything else we can ingest or use on ourselves, has certain side effects. To understand the viability of this drug as a potential cure for different ailments, it is imperative for us to study CBD oil’s side effects in some detail.
- 1 Are there any side effects to using CBD oil?
- 2 Negative Side Effects of Using CBD Oil
- 3 What are the drugs that CBD interacts with?
- 4 When should you avoid CBD oil?
Are there any side effects to using CBD oil?
Incidentally, no cases of toxicity or overdose from use of hemp-based (industrial-grade hemp) CBD oil have been reported so far. In fact, this particular extract of marijuana or hemp has been found to be quite safe for use by almost everyone.Doses of up to 1500 mg of CBD have been seen to be easily tolerated by human test subjects. CBD hardly has any negative impact on humans, may occur only in very rare cases and that too in a mild way.
Negative Side Effects of Using CBD Oil
1. Dryness of Mouth
This is a common phenomenon among people who use CBD or any other cannabinoids – in both cases of consuming or smoking. A phenomenon, which feels like your mouth is stuffed with cotton balls, can be easily overcome by drinking a lot of water or other hydrating fluids before, during or after consumption of CBD.
The reason for this is that when a person consumes or smokes any cannabinoid, the endocannabinoid system, which has its receptors present in the salivary glands, inhibits the secretion of the glands.
Recent studies (1) have discovered that the submandibular gland that produces over 60% of the saliva has cannabinoid receptors.Anandamide,an endocannabinoid that causes dryness of mouth, interacts with these receptors and inhibits saliva production by blocking the signals from the nervous system to produce saliva.
CBD oil typically does not induce any feelings of drowsiness. However, CBD’s effect on humans differs from person to person.In most cases, CBD has a wake-inducing effect, making a person more alert and energetic, while in others it can produce just the opposite reaction. In very high doses, the latter category of people has reported feeling drowsy after consuming CBD. If you belong to this category of people, it is best for you to NOT operate any heavy machinery or drive a vehicle, for your own safety and those around you. As another precaution for people who experience drowsiness as a result of consuming CBD oil, reducing the dosage can be a good option.
3. Dizziness or Lightheadedness
A pretty rare and temporary side effect, lightheadedness can be easily managed by drinking a caffeinated beverage that will help your body quickly regain its normal balance. A cup of tea or coffee can work wonders in such situations, but make sure to drink a lot of water along with it, as caffeine has a dehydrating effect on the body.
4. Drop in Blood Pressure
This is usually the reason why some people experience lightheadedness. While there is evidence of CBD oil helping people with heart diseases and diabetes by lowering their blood pressure, this very quality of this cannabinoid can have negative impact on people with normal blood pressure. According to some studies (2), higher doses of CBD can cause a slight drop in blood pressure. So, people who suffer from low blood pressure or are taking medication for it should refrain from consuming CBD or CBD-based products. While it is always best to consult a doctor before considering CBD oil as an alternative treatment, if faced with such a situation, drinking coffee usually helps, just like in case of lightheadedness.
5. Diarrhea and Change in Appetite & Weight
In 2017,a clinical study of patients with epilepsy and psychotic disorders and their reaction to CBD oil as a form of treatment was published in the journal, Cannabis and Cannabinoid Research. In the course of their research, scientists discovered that the subjects experienced some common side effects like tiredness, diarrhea, and changes in both weight and/or appetite. (3)However, it was concluded that: “In comparison with other drugs, used for the treatment of these medical conditions, CBD has a better side effect profile.”This study, however, left room for more extensive research into the “toxicological parameters” of CBD oil,for instance, its effect on hormones.
6. Effect on patients with movement disorders
A few more possible dangers of CBD use do still exist,particularly among patients of some pre-existing conditions, for example, among patients of dystonic movement disorders. In a study (4), published in the International Journal of Neuroscience in 2009, such patients when treated with oral doses of 100–600mg CBD oil per day for a period of 6 weeks, alongside standard medications, showed signs of improvement. However, that was also accompanied by the common side effects mentioned above (low blood pressure, dryness of mouth, drowsiness and lightheadedness), along with not-so-common psychomotor slowing (or slowing down of thought process and of physical movements). When the dose was above 300 mg/day,symptoms like increase in hypokinesia and resting tremor were noticed, revealing one of the dangers of using CBD oil on patients of Parkinson’s Disease.
However, another study (5), published in the Journal of Psychopharmacology suggested that use of CBD actually improves the quality of life in patients with Parkinson’s disease.This goes to prove that a lot of research needs to be done in this area to derive at a definitive conclusion regarding the benefit and/or negative impact on patients of Parkinson’s Disease.
7. Interaction with pharmaceutical drugs
People taking any pharmaceutical medication for a pre-existing ailment or condition must be particularly careful of CBD’s effects on drug metabolism within the liver. CBD has been found to impede the activity of certain enzymes found in the liver – such as the cytochrome P450 enzyme system (particularly CYP3A4) – that metabolizes pharmaceutical drugs meant for human consumption. According to Davis’s Drug Guide, the P450 enzyme system contains more than 50 enzymes that process and eliminate toxins. (7) If taken in high doses, CBD oil can completely neutralize P450 enzyme’s activity, as this cannabinoid requires the same enzyme to be metabolized. Besides, certain pharmaceutical drugs also inhibit this enzyme. This mean the breakdown of CBD oil may get hindered leading to an increase in its physiological activity. Moreover, there are certain pharmaceutical medications that can actually increase the level of this enzyme, resulting in faster breakdown of CBD.Although such interferences may only be a minor and mostly a temporary issue, it is always safe to consult your doctor before using CBD oil along with pharmaceutical drugs. [You can find a list of the drugs that interact with CBD in a later section.]
8. Side effects of FDA-approved drug for epilepsy
The US Food and Drug Administration approved Epidiolex (a CBD-based drug) oral solution for treatment of two types of epilepsy – Lennox-Gastaut Syndrome and Dravet Syndrome – for patients aged 2 years and above. However, during the course of its clinical trials, researchers found certain adverse effects (6) of the drug:
- Liver problems
- Symptoms related to the central nervous system like irritability and lethargy
- Reduced appetite
- Gastrointestinal problems
- Rashes and other sensitivity reactions
- Reduced urination
- Breathing problems
- Risk of worsening mood swings, depression or suicidal tendencies
What are the drugs that CBD interacts with?
CBD (as discussed earlier) inhibits the breakdown of certain pharmaceutical drugs and, in some cases, vice versa. This may lead to the presence of higher levels of these drugs in your system, causing unwanted side effects, sometimes even an overdose.
It is imperative to note that CBD oil is not alone in this effect on drug metabolism. Grapefruit, watercress, St John’s Wort, and goldenseal also inhibit activity of the cytochrome P450 or CYP450.
The drugs in question…
Any drug that requires the liver’s CYP450 enzymes to metabolize could potentially interact with CBD oil. According to the Indiana University Department of Medicine, drugs known to use the CYP450 system include (7):
- HMG CoA reductase inhibitors
- Calcium channel blockers
- HIV antivirals
- Immune modulators
- Beta blockers
- Angiotension II blockers
- Oral hypoglycemic agents
It must be mentioned here that this list is not exhaustive and neither can it be said with absolution that all these drugs will adversely react with cannabidiol. It is best for you to consult a medical professional before supplementing your treatment with CBD oil.
There is also a group of medicines that fall under the “prodrug” category. These are medications that need to be metabolized to the therapeutic compound. That is to say, when you ingest an inactive compound, it enters your system and is then processed into an active drug. If this processing requires CYP3A4 (part of the larger CYP450 system), then CBD can inhibit the reaction, leaving too little active drug in the body for the desired effect.
Case in point: Codeine that is metabolized into morphine.
Vyvanse and Concerta are two other pharmaceutical medications, meant for ADHD,which also fall under this category.
Cannabis is becoming quite popular as a safe and natural medicine, with virtually zero toxicity. Research has rated this cannabinoid as least dangerous substance, when compared to substances such as alcohol and nicotine in regards to toxicity.
But the question is: Is CBD a natural food supplement or a medicine? Most discussions relating to its legal status depends on that, since “medicinal drugs are considered unsafe until proven safe” while it is just the opposite in case of natural supplements. (8)
Additionally, CBD oil is still unregulated, meaning its correct dosage is still unknown. However, human studies have indicated that CBD is quite very well tolerated even up to a daily dose of 1,500 mg (9).
Cannabidiol is comparatively safe when consumed in appropriate doses among adults. (10)
- CBD doses of up to 300 mg daily have been used safely for up to 6 months.
- Doses of 1200-1500 mg daily have been used safely for up to 4 weeks.
- Cannabidiol under-the-tongue sprays have been used in doses of 2.5 mg for up to 2 weeks.
In fact, according to a recent World Health Organization (WHO) review, “to date, there is no evidence of recreational use of CBD or any public health-related problems associated with the use of pure CBD” .
While the pure form of CBD may be of much benefit to humankind, the main concern is the composition of the products that are being made available in the market. Here, we are talking about the presence of Tetrahydrocannabinol (or THC) (cases of mislabeling) and contaminants.
Mislabeling: According to research paper published in the Journal of the American Medical Association in 2017 (12), almost 70% of all CBD products sold online are mislabeled. This means that they could contain higher traces of THC (only 0.3% and lower is permitted in industrial grade CBD or hemp oil) that could seriously harm patients with anxiety disorders and other psychotic disorders. (19)
Contaminants that are generally added by manufacturers include chemicals added intentionally to heighten its yield, weight, or potency:
- Metal particles
- Synthetic cannabinoids (Fake pot) (15)
Certain other elements that may enter the plant unintentionally are:
- Heavy metals
- Molds and bacteria
Case in point: A recent paper from the Netherlands Ministry of Environment and Health revealed that over 90 percent of the Dutch cannabis sold in coffee shops contains traces of illegal crop protection products like pesticides.(16)
The good news is that most contaminants are quite easy to detect, thanks to the existence of the many professional analytical labs that routinely screen for such contaminants in food crops, imported medicinal plants or edible oils. The same lab methods can be applied to test for contaminants in CBD oils.
When should you avoid CBD oil?
While CBD oil has many therapeutic effects on the human body and mind, there are times and situations when you should avoid CBD oil consumption or use.
i). During Pregnancy
There is evidence of ill-effects of marijuana products on babies, if the mother is using it during her pregnancy or while she is still breastfeeding her child (20, 21 & 22). However, there is no such evidence regarding CBD in its pure form, which has only 0.3% THC at the most. According to some researchers, since cannabinoid receptors are involved in brain development, CBD oil might disrupt fetal brain development. However, others are of the opinion that CBD may, in fact, promote healthy fetal brain development, since CBD can promote neurogenesis.
ii). Bad for Children Below 2 Years of Age
In the absence of proper regulation and sufficient vigilance over the sale of CBD products, it is not safe to administer CBD in any form to babies and children below the age of 2 years. What effect even the tiny traces of THC may have on your baby and whether your baby may get affected by the trace elements of contaminants are not risks you’d want to take with your little one’s health. It is best to ensure you are using CBD in its purest form and that too only after consulting a doctor experienced in CBD’s effects.
iii).When Taking Antipsychotic, Antidepressant Drugs
This has been explained earlier in “What are the drugs that CBD interacts with?” and a sub-section under “Are there any side effects to using CBD oil?”
In spite of its safety concerns, it is undeniable how a lot of people are increasingly choosing CBD products over pharmaceutical ones for treatment of different ailments – both physical and mental. This is mostly due to its fewer side-effects and next-to-nil chance of overdosing.
Taking advantage of the rise in demand, a lot of unscrupulous manufacturers and cannabis growers have come into the industry with the sole intent of making money, without paying much thought to the welfare of the people to whom they sell their products.
So, it is up to us as consumers to be careful and do our own research before we take a chance on CBD products available in the market, especially online ones.
- FDA approves first drug comprised of an active ingredient derived from marijuana to treat rare, severe forms of epilepsy https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm611046.htm
- Effectiveness of Cannabidiol Oil for Pediatric Anxiety and Insomnia as Part of Posttraumatic Stress Disorder: A Case Reporthttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5101100/
- Medical Cannabinoids in Children and Adolescents: A Systematic Review https://pediatrics.aappublications.org/content/140/5/e20171818?sso=1&sso_redirect_count=1&nfstatus=401&nftoken=00000000-0000-0000-0000-000000000000&nfstatusdescription=ERROR%3A%20No%20local%20token
- Marijuana may be a miracle treatment for children with autism https://www.usatoday.com/story/news/world/2017/04/25/marijuana-pot-treatment-children-autism-cannabis-oil/100381156/
- Composition and Use of Cannabis Extracts for Childhood Epilepsy in the Australian Community
- Cannabidiol (CBD) — what we know and what we don’t
- An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5569602/
- Potential Clinical Benefits of CBD-Rich Cannabis Extracts Over Purified CBD in Treatment-Resistant Epilepsy: Observational Data Meta-analysis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6143706/
- Drugs that May Interact with CBD Oil https://cbdoilreview.org/cbd-cannabidiol/cbd-p-450-enzyme/
- A Cross-Sectional Study of Cannabidiol Users
- Cannabinoid Ligands and Alcohol Addiction: A Promising Therapeutic Tool or a Humbug?https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4701763/
(*1) A drug with a mind-altering effect
(*2) A cannabinoid is a class of diverse chemical compounds that targets the body’s endocannabinoid system, altering neurotransmitter release in the brain.
(13) The Health effects of cannabis and cannabinoids: the current state of evidence and recommendations for research. National Academies of Sciences, Engineering, and Medicine [https://www.nap.edu/catalog/24625/the-health-effects-of-cannabis-and-cannabinoids-the-current-state] &Health and Medicine Division; Board on Population Health and Public Health Practice [http://nationalacademies.org/hmd/About-HMD/Leadership-Staff/HMD-Staff-Leadership-Boards/Board-on-Population-Health-and-Public-Health-Practice.aspx]
(14) Evaluating the Effects of Gamma-Irradiation for Decontamination of Medicinal Cannabis [https://www.ncbi.nlm.nih.gov/pubmed/27199751]
(15) ‘Fake pot’ causing zombie like effects is 85 times more potent than marijuana [https://edition.cnn.com/2016/12/16/health/zombie-synthetic-marijuana/]
(16) Cannabis contaminanten https://www.rijksoverheid.nl/documenten/rapporten/2016/01/18/cannabis-contaminanten
(17) Steep Hill, ACCL Find Pesticides in Over 50% of Cannabis Samples [https://cannabisindustryjournal.com/news_article/steep-hill-accl-find-pesticides-in-over-50-of-cannabis-samples/]
(18) Random testing, million-dollar fines: Canada’s cannabis pesticide crackdown [https://www.leafly.com/news/industry/random-testing-million-dollar-fines-canadas-cannabis-pesticide-crackdown]