Decarboxylation

Decarboxylation is the chemical reaction in which acidic cannabinoids lose a carboxyl group, usually through heat or time, and become their neutral forms.

In the living hemp plant, cannabinoids exist mostly as acids: CBDA rather than CBD, THCA rather than THC. Heating during drying, extraction or manufacturing drives carbon dioxide off the molecule and converts the acid to the neutral compound. The same change happens slowly at room temperature over long storage.

The reaction matters for reading test results in two ways. First, the same sample can show different numbers depending on whether the method heats it, which is why total THC and total CBD figures apply a conversion factor to the acid forms. Second, a product described as raw or acidic will show high CBDA and low CBD on its certificate, and that is expected rather than a sign of a problem. Whether the acid or neutral form is preferred is a formulation choice, and research comparing the two is limited.