CBD means cannabidiol and is the second most abundant cannabinoid in cannabis. Scientists have been studying CBD since the 1970s, together with its counterpart THC, bringing the medical potential of cannabis and the hypothetical risks when used recreationally face-to-face. But during all this time we have been gathering more and more evidence that CBD can offer similar or even better medical benefits than THC but without THC's added psychoactive effects.
Even the World Health Organization believes that CBD has great therapeutic potential. Their recent cannabidiol critical review report stated that CBD is a promising treatment for several medical pathologies: it is generally well tolerated, it has a good safety profile, and does not seem to have dependence potential or other health-related risks.
There is hardly any scientific evidence for any dangerous secondary effects related to CBD. Experience seems to indicate that CBD has no negative impact on humans, although some mild negative effects can appear in isolation.
This is what science has to say about this:
1- Mouth dryness
Mouth dryness is a common occurrence amongst people who use CBD or any other cannabinoids. Recent studies have discovered that the submandibular gland, which produces over 60% of the total saliva, has cannabinoid receptors. Anandamide is an endocannabinoid that causes mouth dryness, just like phytocannabinoids such as CBD. Anandamide interacts with these receptors and stops saliva secretion by blocking the signals from the nervous system to produce saliva, something that can be easily overcome by drinking a lot of water or other hydrating liquids.
2- Drowsiness
CBD does not normally produce any feelings of drowsiness. However, CBD's effect on humans varies from person to person. In most cases, CBD causes a wake-inducing effect, making users more alert and energetic, but it can also produce the opposite effect in some. As a precaution, reducing the dosage may be a good option.
3- Dizziness or lightheadedness
This is a rare and rather temporary secondary effect. CBD-induced dizziness normally occurs when the dosage is higher than necessary. This can easily happen with vaping, as controlling this consumption method requires a certain level of skill. Lightheadedness can be easily controlled by drinking a caffeinated beverage like tea or coffee, which will help the body recover its normal balance.
4- Drop in blood pressure
This is usually the reason why some people experience lightheadedness. While there is evidence that CBD can help heart disease and diabetes sufferers by lowering their blood pressure, this cannabinoid can have a negative impact on people with normal blood pressure. According to some scientific studies, higher doses of CBD can produce a slight drop in blood pressure. This is the reason why people with low blood pressure, or those who are taking medication for it, should avoid CBD consumption and always consult a doctor before use.
5- Diarrhea and change in appetite
In 2017, a clinical study was published on epilepsy patients and their reaction to CBD oil as a form of treatment. In the course of their research, scientists discovered that these patients experienced some common side effects, such as diarrhea and changes in both weight and appetite. However, it was concluded that "in comparison with other drugs, used for the treatment of this medical condition, CBD has a better side effect profile."
6- Effect on patients with movement disorders
In a study published in the International Journal of Neuroscience in 2009, patients who were treated with daily oral doses of 100-600 mg of CBD oil, along with standard medication, showed signs of improvement. But when the dose was higher than 300 mg per day, symptoms such as hypokinesia (decreased speed of bodily movement) and resting tremor were noticed. This reveals the negative impact that CBD oil can have on Parkinson's Disease sufferers. However, a later study published in the Journal of Psychopharmacology suggested that the use of CBD actually improves the quality of life of patients with Parkinson's Disease. This proves that a lot more research on this is needed in order to obtain a definitive conclusion regarding the benefits and/or negative impact on these patients.
7- Interaction with pharmaceutical drugs
CBD has been found to impede the activity of certain enzymes in the liver, such as the cytochrome P450 enzyme system (particularly the enzyme CYP3A4), which metabolizes pharmaceutical drugs destined for human consumption. The use of CBD alongside pharmaceutical drugs that inhibit these enzymes could pose a health risk, as CBD can increase or decrease the levels of these medications in the blood stream, which could in turn damage the liver. Here you can find a list of pharmaceutical drugs that may interact with CBD oil.
8- Reproductive problems
Natural cannabinoids are produced and used as chemical messengers. One of their most important functions is helping our body to coordinate conception and pregnancy. For now, the method of how they regulate our ability to reproduce is still a mystery. Some evidence suggests that regular cannabis users have slightly lower fertility rates, although more thorough studies generally agree that this is minimal, and is more likely to be caused by THC rather than CBD.
9- Immune system issues
CBD is known as an immunomodulator because it can help regulate and influence the function of hyperactive immune systems. However, there is growing concern that this could be detrimental for patients with weakened immune systems, for instance HIV sufferers. Even though we do not have evidence to prove this theory, research has shown that cannabis helps alleviate pain and other HIV-related symptoms, without causing serious side effects. And when marijuana is taken for the treatment of HIV-specific symptoms like hepatic fibrosis, cannabinoids do not seem to have a damaging effect on patients.
Although current research studies suggest that CBD could be more useful than detrimental for the treatment of immunodeficient patients, like with other aspects of this cannabinoid, more research is still needed to scientifically prove its side effects and find possible solutions.