Decarboxylation of cannabidiol (CBD)

In connection with cannabinoids from the cannabis plant, the term decarboxylation or oxidative decarboxylation is often mentioned. What exactly is behind this and why this chemical reaction is necessary for the production of a high-quality CBD oil will be explained in the following article.

When it is said that hemp produces cannabinoids, this is not technically correct. This is because the plant produces so-called cannabinoid acids (carboxylic acids), which are also called inactive acid forms. They are the precursors of the actual cannabinoids.

This means that important cannabinoids like cannabidiol (CBD) and tetrahydrocannabinol (THC) are basically not present in the cannabis plant, but their acid precursor is. In the case of CBD, this is cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA). The letter A stands for the English word acid.

Do cannabinoid acids have an effect?

There are hardly any studies that have investigated the acid form of cannabinoids. A study on rodents indicates a possible therapeutic potential. Researchers were able to show in a mouse model that CBDA could be effective in the treatment of nausea and anxiety. However, research in this area is still in its infancy.

An interesting piece of information is that THCA, in contrast to the psychoactive THC, does not have an intoxicating effect. Accordingly, the consumption of raw hemp is harmless.

What is decarboxylation?

Decarboxylation (or oxidative decarboxylation) is a chemical process that occurs naturally when the plant material is exposed to the sun and air without protection. This changes the chemical structure of the carboxylic acids. Incidentally, the same happens when cannabis is smoked or vaporised.

Cannabinoids in their acid form have a carbon-oxygen-hydrogen molecular bond (-COOH) known as carboxyl. As these bonds are unstable, they are quickly broken by heat and one molecule splits off. In simple terms, this means that the acid (A) splits off, so that CBDA turns into CBD and THCA into THC - in other words, into its active form.

To avoid having to wait for the natural process, manufacturers of CBD oils, for example, decarboxylate the plant material with heat.

What has to be taken into account during decarboxylation?

Now, it can be assumed that it is sufficient to simply heat the plant material to bring about the conversion of the cannabinoids from their inactive to the active form. However, it is not quite that simple. Because the right temperature is very important here.

With regard to decarboxylation and temperature, the following rule applies: the lower the temperature and the longer the heating, the more valuable plant substances remain. Too high and too short a heat can cause CBDA to lose a lot of the CBD.

Accordingly, the challenge with decarboxylation is not to heat the cannabis material too hot, so that as few ingredients and cannabinoids as possible simply "evaporate".

Advantages of decarboxylation

The cannabis plant is not very vulnerable at the end of the cultivation cycle. Nevertheless, the plant can become contaminated with pathogens (microorganisms) during storage after harvest. Decarboxylation draws the moisture out of the cannabis flowers. As a result, the risk of contamination is minimised.

Decarboxylation of THC and CBD

With the help of low temperatures and prolonged heating, it should be possible to convert about 95 percent of the cannabinoid acids into the active form. At the same time, the degradation of THC to cannabinol (CBN) should be limited to about ten percent.

By way of explanation:
If heated for too long, the THC oxidises to the less effective cannabinoid CBN.

It is recommended to carry out the procedure for the extraction of cannabinoids as follows:

  • Heat the plant material for 10 to 20 minutes at a temperature of 100 to 110 degrees Celsius so that the residual water can evaporate.
  • Then heat again for about 60 to 120 minutes at a temperature of 100 to 110 degrees Celsius. In this way, the conversion of THCA into THC usually takes place without any problems. If CBD is of great importance, the heating should take one hour at a temperature of 120 degrees Celsius.

Many other active ingredients from cannabis, such as the terpenes, are preserved at these temperatures. Terpenes are responsible for the smell and taste of cannabis. They also have certain therapeutic benefits, or rather they support the effect of the cannabinoids, which then interact with the (body's) endocannabinoid system after use.

Process for the production of CBD oil

In order to produce a high-quality full-spectrum CBD oil, the following factors play a particularly important role:

    • Organic hemp as the starting material
    • preferably hand-harvested
    • optimal storage of the harvested hemp material
    • decarboxylation with the right temperatures/duration
    • environmentally friendly and gentle CO2 extraction
    • increasing the viscosity of the CBD extract with organic hemp oil

    On the subject of CO2 extraction: there are various methods for extracting CBD. The CO2 extraction process has proved particularly successful, as it not only extracts the cannabinoids, but also all other active ingredients from cannabis (e.g. terpenes, flavonoids, etc.), resulting in a high-quality full-spectrum product.

    Despite decarboxylation, a small part of the precursor of CBD remains. Research suggests that the simultaneous use of CBDA with CBD can even increase the bioavailability of CBD. Nevertheless, the CBD content in CBD oil should always be higher than the CBDA content. In addition, attention should also be paid to the THC content. This should not exceed the permissible value.


    How long does decarboxylation take?

    With the help of decarboxylation, the THCA, CBDA and other cannabinoid acids in the cannabis flowers can be converted into the active form THC and CBD. It is recommended to first heat the flowers at a temperature between 100 and 110 degrees Celsius for 10 to 20 minutes. Thanks to this process, the residual water can evaporate. Afterwards, the cannabis flowers should be heated again at the same temperature for 60 to 120 minutes.

    What is oxidative decarboxylation?

    Oxidative decarboxylation is a chemical reaction. Heat is used to convert the acids THCA and CBDA into the active form THC and CBD by splitting off a carbon dioxide molecule from the acid. In this process, choosing the right temperature and heating time is important. It is important to note that the cannabinoids will oxidise if the temperature is too high.

    What are the benefits of decarboxylation?

    Decarboxylation (heating) converts a cannabinoid acid (e.g. THCA or CBDA) into an active cannabinoid (e.g. THC or CBD). This process takes place automatically when smoking or vaporising cannabis. However, in order to add active cannabinoids to products (e.g. CBD oil), decarboxylation is essential.