Several studies suggest that CBD is non-toxic in non-transformed cells and does not induce changes on food intake, does not induce catalepsy, does not affect physiological parameters (heart rate, blood pressure and body temperature), does not affect gastrointestinal transit and does not alter psychomotor or psychological functions. Also, chronic use and high doses up to 1,500 mg/day of CBD are reportedly well tolerated in humans. Based on recent advances in cannabinoid administration in humans, controlled CBD may be safe in humans and animals. However, further studies are needed to clarify these reported in vitro and in vivo side effects.
There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Despite its molecular similarity to THC, CBD only interacts with cannabinoid receptors weakly at very high doses (100 times that of THC), and the alterations in thinking and perception caused by THC are not observed with CBD. The different pharmacological properties of CBD give it a different safety profile from THC.
A review of 25 studies on the safety and efficacy of CBD did not identify significant side effects across a wide range of dosages, including acute and chronic dose regimens, using various modes of administration.xli CBD is present in nabiximols which, is approved throughout most of Europe and in other countries. Because of this, there is extensive information available with regard to its metabolism, toxicology, and safety. However, additional safety testing among specific patient populations may be warranted should an application be made to the Food and Drug Administration.
Source: National Institute on Drug Abuse (USA)
THC SAFETY – Side effects and warnings
Cannabinoids are likely safe when used for specific conditions at the recommended doses for the recommended amount of time. Side effects have mostly been linked to THC, the active ingredient in Cannabis sativa. Dizziness is a common side effect. Marijuana may have effects on almost every organ system in the body, including the central nervous, heart, endocrine, and immune systems.
Use cautiously with alcohol. Combining alcohol and CBD may cause significantly low blood alcohol levels compared to alcohol alone, though similar effects may occur. Marijuana may increase the risk of bleeding. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
Marijuana may affect blood sugar levels. Caution is advised in people with diabetes or blood sugar problems, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary. Marijuana (THC included) may cause low blood pressure.
Use cautiously in people who have liver disease or those using agents toxic to the liver. Use cautiously in people who are taking barbiturates, antipyrine, or central nervous system (CNS) depressants. Marijuana may interfere with the way the body processes certain agents using the liver’s cytochrome P450 enzyme system. As a result, the levels of these agents may be increased in the blood and may cause increased effects or potentially serious adverse reactions. People using any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
Use cautiously in people who are on estrogen therapy. Use cautiously in people who have immune disorders or those taking agents that may affect the immune system. Use cautiously in people who are taking p-glycoprotein-regulated drugs. Use cautiously in people who have a history of drug abuse or addiction. Marijuana may be addictive.
Use cautiously in people who have or are at risk of eye problems. Marijuana may cause eye problems and dry eyes, and it may increase eye pressure. Use cautiously when consuming foods or supplements that contain cannabis seeds or oil. These products may contain a high level of THC that may trigger a positive drug screen. Use cautiously in people who are at risk of seizure or those using antiseizure drugs. Marijuana may cause seizures.
Use cautiously in people who have or are at risk of heart disease. Marijuana may cause abnormal heartbeat, disrupted blood flow to organs (kidney, spleen), heart attack, and heart failure.
Use cautiously in people who have or are at risk of musculoskeletal disorders. Marijuana may cause bone problems, increased risk of side effects linked to musculoskeletal or connective tissue disorders, falls, muscle problems (pain, twitching, or weakness), numbness, recurrence in multiple sclerosis, reduced coordination, restlessness, and speech disorders.
Use cautiously in all otherwise healthy people who are not taking any medications. Marijuana may cause disorientation, dizziness, headaches, fatigue, a feeling of intoxication, lightheadedness, and reduced attention.
Avoid in women who are pregnant, breastfeeding, or trying to get pregnant. Marijuana may have serious risks and may cause low birthweight or abnormalities in the baby. Avoid long-term use in people who have or are at risk of lung problems, such as asthma or byssinosis (a disease caused by breathing dust). Marijuana may cause bronchitis, coughing, lung cysts, phlegm, reduced lung density, and wheezing. Avoid using cannabis products that have been obtained illegally. These products may contain unknown and possibly harmful ingredients, such as the animal tranquilizer PCP.
Pregnancy and Breastfeeding: avoid using marijuana in women who are pregnant, breastfeeding, or trying to get pregnant. Research strongly suggests that marijuana may have serious risks for the child, including abnormalities, cancer, development problems, increased leukemia risk, low birthweight, and reduced attention skills. Cannabis may affect the mother’s judgment and ability to care for the child, and it should not be smoked around infants or children. Cannabis may be passed to babies through breast milk.
Source: Mayo Clinic (USA)