# CBDA

> CBDA (cannabidiolic acid) is the acid cannabinoid made by CBDA synthase from CBGA; it dominates hemp-type and CBD-type cannabis and decarboxylates to CBD.

- Canonical: https://genetixbay.com/knowledge/glossary/cbda.html
- Also written: CBD-A, cannabidiolic acid
- Glossary category: Cannabinoids and terpenes · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

CBDA, cannabidiolic acid, is the form in which the plant stores [CBD](https://genetixbay.com/knowledge/glossary/cbd.md). [CBDA synthase](https://genetixbay.com/knowledge/glossary/cbda-synthase.md) cyclises [CBGA](https://genetixbay.com/knowledge/glossary/cbga.md) into CBDA in the [trichome head](https://genetixbay.com/knowledge/glossary/trichome-heads.md), competing with [THCA synthase](https://genetixbay.com/knowledge/glossary/thca-synthase.md) for the same CBGA supply. [Decarboxylation](https://genetixbay.com/knowledge/glossary/decarboxylation.md) by heat or time turns CBDA into CBD.

## In practice

Plants with two functional CBDA synthase alleles and no functional THCA synthase make mostly CBDA; plants with one of each tend toward a balanced 1:1 profile. A breeder crossing a THCA-type with a CBDA-type parent typically sees a mix of THC-type, balanced and CBD-type offspring in the F2, roughly following simple Mendelian ratios at that locus, though real data are messier. Feeding, light or stress do not switch a plant from [THCA](https://genetixbay.com/knowledge/glossary/thca.md) to CBDA.

## Units and formula

1 g of CBDA can yield at most [0.877](https://genetixbay.com/knowledge/glossary/total-thc.md) g of CBD. Total CBD = CBD + 0.877 × CBDA.

## Don't confuse with

- **CBD**: the neutral product of decarboxylation.
- **CBGA**: the shared precursor of both CBDA and THCA.
- **THCA**: the alternative product of the same precursor, from a different enzyme.

## Related terms

[CBD](https://genetixbay.com/knowledge/glossary/cbd.md), [CBDA synthase](https://genetixbay.com/knowledge/glossary/cbda-synthase.md), [CBGA](https://genetixbay.com/knowledge/glossary/cbga.md), [Chemotype ratio](https://genetixbay.com/knowledge/glossary/chemotype-ratio.md), [Total CBD](https://genetixbay.com/knowledge/glossary/total-cbd.md)

## Read more

- [Chemotype inheritance: how THC and CBD synthase alleles pass on](https://genetixbay.com/knowledge/breeding/chemotype-inheritance.md)

## Sources

1. Taura F, Sirikantaramas S, Shoyama Y, et al. 2007. Cannabidiolic-acid synthase, the chemotype-determining enzyme in the fiber-type Cannabis sativa. FEBS Letters 581(16):2929-2934.
2. Wang M, Wang YH, Avula B, et al. 2016. Decarboxylation study of acidic cannabinoids: a novel approach using ultra-high-performance supercritical fluid chromatography/photodiode array-mass spectrometry. Cannabis and Cannabinoid Research 1(1):262-271.