CBD oil side effects: what you should know

Note: this article gives a general overview of the current scientific knowledge on CBD oil side effects. It does not contain any recommendation for intake and is no substitute for medical advice. The CBD oils from MAGU are placed on the market as mouth and gum cosmetics and are to be used exclusively in accordance with the directions on the respective product.

CBD oil side effects: what you should know

CBD oil is used today for very different products. These include cosmetic care oils, orally used preparations and high-dose CBD medicines. Reports of possible side effects vary accordingly.

Anyone searching for CBD oil side effects should therefore always pay attention to which product and which type of use is involved. A large part of the available safety data comes from the medical use of purified CBD. In some cases, several hundred to well over a thousand milligrams of CBD per day were used – often together with other medicines.

These results cannot be transferred directly to every freely available CBD product. The CBD oils from MAGU are offered as cosmetics for the care of the mouth and gums. Only the use described on the respective product applies to them.

Do you take medication regularly? Check here who should not take CBD.

What is CBD?

CBD stands for cannabidiol and is a natural component of the hemp plant. Unlike THC, pure CBD does not cause the intoxication typical of cannabis. If you would like to explore the differences between cannabinoids in more depth, you will find an overview in our comparison CBD vs. HHC vs. H4CBD.

However, this does not mean that CBD has no effect on the body at all. Purified cannabidiol is used, among other things, as a prescription medicine for the treatment of certain rare forms of epilepsy. Much of what is known today about CBD oil side effects and interactions comes from these medical applications. The amounts of CBD used there differ considerably from those that come into contact with the oral mucosa during cosmetic use as intended.

Which CBD oil side effects have frequently been described?

Two of the most frequently and repeatedly described side effects of oral or medicinal CBD use are:

Tiredness and drowsiness
reduced appetite

Both reactions are also listed in the official information on the approved CBD medicine Epidyolex. How likely they are to occur depends, among other things, on the amount of CBD, the duration of treatment, individual sensitivity and medication taken at the same time. (European Medicines Agency: Epidyolex)

Drowsiness in particular was observed more frequently in the drug studies in patients who received clobazam in addition to CBD. Clobazam belongs to the benzodiazepines. CBD can increase the concentration of an active breakdown product of clobazam and thereby intensify its sedative effect.

These findings come from the medical intake of high amounts of CBD. They do not mean that the same effects are to be expected from the cosmetic use of a CBD-containing oral care oil.

What role does the amount of CBD play?

The amount of CBD used is decisive for assessing possible side effects. In drug studies, CBD was usually dosed according to body weight. Daily amounts of 10, 20 or 25 milligrams of CBD per kilogram of body weight were studied, for example.

For a person weighing 70 kilograms, this would correspond to:

10 mg/kg: 700 mg CBD daily
20 mg/kg: 1,400 mg CBD daily
25 mg/kg: 1,750 mg CBD daily

These are very high amounts used medically. They were used to treat serious illnesses under medical supervision and are not a dosage recommendation for freely available CBD products.

The official drug data also show a clear dose dependency of certain safety risks. Increases in the liver enzyme ALT to more than three times the upper limit of normal were observed in around 15 per cent of patients on 20 or 25 mg CBD per kilogram per day. At 10 mg/kg/day it was around 3 per cent. (Epidyolex summary of product characteristics: dosage and liver values)

CBD and liver values

The changes in liver values observed in drug studies occurred mainly at very high medical doses of CBD. The risk was also significantly greater when valproate and in some cases also clobazam were used at the same time.

In the controlled studies with 10, 20 or 25 mg CBD per kilogram of body weight per day, ALT increases to more than three times the upper limit of normal were observed in 23 per cent of patients who were receiving valproate and clobazam at the same time. With valproate without clobazam it was 19 per cent. With clobazam without valproate, and without either of these two medicines, it was around 3 per cent in each case.

The abnormal liver values were thus not exclusively, but very clearly, associated with high amounts of CBD and certain concomitant medications. No comparable burden can be derived from the intended cosmetic use of an oral care oil. Equally wrong would be the sweeping statement that CBD could not affect the liver under any circumstances.

CBD and interactions with medication

CBD is processed in the liver and intestine via various enzyme systems. At the same time, cannabidiol can influence how certain other active substances are broken down. This is often simplified as the CYP450 system. In fact, it is a whole group of enzymes. In the case of CBD, CYP2C19 and CYP3A4, among others, are important.

Whether an interaction is medically relevant depends on the specific medicine, its dose, the amount of CBD absorbed and individual metabolism. Combinations with medicines for epilepsy have been particularly well studied. Many of the stronger interactions and abnormal liver values were observed in studies in which CBD was used in addition to valproate, clobazam or other medicines.

Sweeping lists of supposedly prohibited combinations are therefore of little help. Anyone who uses CBD orally independently of cosmetic products and takes medication regularly should have the specific combination checked by a doctor or pharmacist. This information is not a recommendation to ingest MAGU’s mouth and gum cosmetics.

CBD and diazepam

Diazepam belongs to the benzodiazepines and has a calming, anxiety-relieving and muscle-relaxing effect. Among other routes, it is processed via the enzyme CYP2C19. CBD can inhibit this enzyme and thereby possibly influence the concentration of diazepam.

In addition, the calming effects of both substances can overlap. Tiredness, drowsiness, light-headedness and impaired reactions can be more pronounced as a result. Diazepam is explicitly named in the drug information on CBD as a possible CYP2C19 substrate. (Epidiolex: information on possible drug interactions)

How relevant this interaction is in an individual case depends on the diazepam dose, the amount of CBD absorbed and individual metabolism. Anyone using diazepam or another benzodiazepine should therefore seek medical advice before additionally using CBD orally.

CBD and alcohol

With CBD and alcohol, too, a nuanced view is necessary. Alcohol can cause tiredness, light-headedness and impaired reactions. As orally ingested CBD can also make you drowsy, these effects can be intensified. The drug information on Epidiolex explicitly points out that alcohol and other depressant substances can increase the drowsiness and sedation caused by CBD.

In addition, there are experimental indications of possible cell-protective properties of CBD:

Hamelink et al. (2005): In a rat model, CBD reduced alcohol-induced neurodegeneration in the hippocampus and entorhinal cortex in a dose-dependent manner; at 40 mg/kg by around 60%. Animal experiment, no evidence in humans.
Yang et al. (2014): In mice and liver cell models, CBD influenced alcohol-induced fat deposits and oxidative stress. Also preclinical.

It must not be concluded from these results that CBD protects people from alcohol-related brain or liver damage. There is no corresponding clinical evidence. CBD therefore neither makes drinking alcohol safer nor cancels out the impairment caused by alcohol.

Who should be particularly careful?

Particular caution is advisable with intended oral use of CBD if medication is being taken at the same time. This applies above all to medicines with a calming effect or a narrow therapeutic range.

People with known liver disease should also seek medical advice before oral use. The reason for this is the dose-dependent changes in liver values that were observed with very high medical amounts of CBD.

There are insufficient safety data for pregnancy and breastfeeding. For children and adolescents, too, findings from medically supervised epilepsy treatment cannot be transferred to general use of freely available CBD products. For MAGU’s mouth and gum cosmetics, the information on the respective packaging applies.

Is CBD addictive?

According to the assessment of the World Health Organization, there is no evidence of abuse or dependence potential for pure CBD. CBD causes neither the intoxication typical of THC nor a comparable consumption experience. (WHO: Cannabidiol – Critical Review Report)

In its assessment, the WHO also concluded that, according to the knowledge at the time, pure CBD does not pose a relevant public health problem. This assessment refers to cannabidiol itself and not automatically to every product sold under the name CBD oil. What matters, therefore, is whether the actual composition of a product matches its declaration – which is why we have our CBD oils analysed externally (Quality & certificates of analysis).

CBD in addiction research

CBD is not only being studied because of its lack of dependence potential. There is also research into whether cannabidiol could influence cue-induced desire – so-called craving – in certain addictive disorders.

Hurd et al. (2019): In an exploratory, randomised, placebo-controlled study of abstinent people with heroin dependence, CBD (400 or 800 mg on three consecutive days) reduced craving triggered by heroin-related cues, and the associated anxiety, more than placebo. Part of the effect was still measurable seven days later. However, the study does not prove that CBD treats opioid dependence or prevents relapses.
Mongeau-Pérusse et al. (2021): In people with cocaine dependence, 800 mg CBD daily reduced neither craving nor the relapse rate significantly compared with placebo.
Hindocha et al. (2018): After a single dose of 800 mg CBD, reduced attention to cigarette cues was observed. However, subjective craving and withdrawal symptoms were not reduced.

CBD is therefore being researched as a possible approach for individual aspects of addictive disorders. However, it is currently not a generally established or approved addiction therapy. These studies, too, used very high orally administered amounts of CBD and are unrelated to the cosmetic purpose of our oral care oils.

Does CBD get you “high”?

Pure CBD does not cause intoxication typical of THC. The prerequisite, however, is that the composition of the product used actually matches the declaration. For the legal classification of other cannabinoids, see our article on THCA and the legal situation in Austria.

On our CBD oils, the THC content is stated as a precaution as below 0.2 per cent. In the current laboratory analyses of our oils, no THC was detected. Scientifically speaking, this means that the THC content was below the limit of detection or quantification of the respective analytical method. An absolute concentration of exactly 0.0000 per cent cannot be proven analytically. “THC not detected” is therefore the more accurate wording than “0% THC”.

What role does product quality play?

Good product quality does not automatically prevent every individual reaction. However, it reduces avoidable risks from contamination, incorrect concentration information or a composition that deviates from the declaration.

What matters is a transparent list of ingredients, a clear intended purpose, understandable directions for use and external laboratory analyses. With claims such as “THC-free”, it should also be clear which limit of detection the statement refers to.

At MAGU we use 100% Austrian hemp and have our CBD products analysed externally. In the current analyses of our CBD oils, no THC was detected.

CBD as mouth and gum cosmetics

Cosmetic products may be expressly intended for use on the teeth and the oral mucosa. Their purpose may include cleaning, protecting or caring for the oral cavity (EU Cosmetics Regulation).

The CBD oils from MAGU are placed on the market as cosmetic products for the care of the mouth and gums. They are neither medicines nor food supplements and are not offered for the treatment of diseases. Information from studies with orally administered, high-dose CBD is not a recommendation to ingest our oils, to increase the amount used or to aim for a therapeutic effect with them.

Frequently asked questions about CBD oil side effects

Which CBD oil side effects are common?

Tiredness or drowsiness and reduced appetite are among the frequently described side effects of oral and medicinal CBD use. A particularly large amount of safety data comes from drug studies with high CBD doses and simultaneous use of other medicines.

Why are the amounts of CBD used in studies important?

In medical studies, 10 to 25 mg CBD per kilogram of body weight per day were often used. For a person weighing 70 kg, this corresponds to 700 to 1,750 mg CBD daily. Results from this dose range cannot simply be transferred to other products and uses.

Can CBD put a strain on the liver?

Very high CBD doses used medically can increase liver values. The risk was significantly greater at 20 or 25 mg/kg and when valproate was taken at the same time. These data cannot be transferred to the intended cosmetic use of an oral care oil.

Can CBD make you tired?

Yes. Tiredness and drowsiness are among the repeatedly described effects of oral or medicinal CBD use. Together with alcohol or sedative medication, this effect can be stronger.

Can CBD affect appetite?

Reduced appetite has been regularly reported in clinical studies with medically used CBD. How strong the effect is depends on the group of people, the amount of CBD and concomitant medication.

Is CBD compatible with diazepam?

CBD can influence the breakdown of diazepam. In addition, the calming effects can overlap. An oral combination should therefore be clarified medically.

Is CBD compatible with alcohol?

CBD and alcohol can intensify tiredness and light-headedness. Preclinical studies provide indications of possible protective effects of CBD against certain alcohol-related damage – however, such protection has not been proven in humans.

Can CBD help with addiction?

CBD is being studied as a possible approach for addictive disorders. One clinical study showed a reduction in craving triggered by heroin-related cues. In cocaine dependence, no significant reduction was found. CBD is currently not a generally established addiction therapy.

Can CBD be addictive?

According to the WHO’s assessment, there is no evidence of relevant abuse or dependence potential for pure CBD.

Do MAGU CBD oils contain THC?

On the products, the THC content is stated as below 0.2 per cent. In the current laboratory analyses, no THC was detected – which means the value was below the limit of detection or quantification of the analytical method.

Does the medical information also apply to the CBD oils from MAGU?

No. The medical data described come mainly from studies with orally administered, very high-dose CBD. The CBD oils from MAGU, by contrast, are cosmetic products for the care of the mouth and gums and are to be used in accordance with the directions on the product.

Conclusion: putting CBD oil side effects into perspective

According to the WHO’s assessment, CBD has no relevant dependence potential. Tiredness or drowsiness and reduced appetite are among the repeatedly described side effects of oral or medicinal use.

Other medically important safety findings were studied mainly at very high amounts of CBD and often together with other medicines. This is particularly clear with liver values: the higher risk rates come from studies with 20 or 25 mg/kg/day – for 70 kg this corresponds to 1,400 to 1,750 mg CBD daily.

Interactions must also be considered in the right context. CBD can intensify the calming effect of alcohol and benzodiazepines and influence the breakdown of individual medicines. Experimental indications of protection against alcohol-related damage are interesting, but so far are not proof of a protective effect in humans.

A clear distinction applies to our CBD oils: they are offered as mouth and gum cosmetics and are to be used exclusively in accordance with the cosmetic use described on the respective product.