# Acid vs neutral cannabinoids

> Acid cannabinoids (THCA, CBDA, CBGA) are the carboxylated forms the plant makes; neutral cannabinoids (THC, CBD, CBG) form when heat or time removes the carboxyl group.

- Canonical: https://genetixbay.com/knowledge/glossary/acid-vs-neutral-cannabinoids.html
- Also written: acidic cannabinoids, neutral cannabinoids, acid cannabinoids, carboxylated cannabinoids, decarboxylated cannabinoids, acid forms
- 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"

Cannabis makes its cannabinoids as carboxylic acids, marked with an "A" ([THCA](https://genetixbay.com/knowledge/glossary/thca.md), CBDA, [CBGA](https://genetixbay.com/knowledge/glossary/cbga.md), CBCA, [THCVA](https://genetixbay.com/knowledge/glossary/thcva.md)). The acids are the biosynthetic products of the trichome enzymes. Their neutral forms ([THC](https://genetixbay.com/knowledge/glossary/thc.md), [CBD](https://genetixbay.com/knowledge/glossary/cbd.md), [CBG](https://genetixbay.com/knowledge/glossary/cbg.md), CBC, [THCV](https://genetixbay.com/knowledge/glossary/thcv.md)) appear when the carboxyl group leaves as CO2 during [decarboxylation](https://genetixbay.com/knowledge/glossary/decarboxylation.md), mostly through heat, slowly through storage.

## In practice

Raw and cured flower is mostly acids; smoke, vapour and cooked products are mostly neutrals. That's why a flower COA lists both and why labels report calculated "total THC". The distinction also drives lab method choice: HPLC measures the acids and neutrals separately at room temperature, while GC heats the sample, converts most acids in the inlet and reports neutrals unless the sample is derivatised first.

## Units and formula

Neutral = acid × conversion factor: about 0.877 for THCA to THC and CBDA to CBD, 0.878 for CBGA to CBG and 0.867 for THCVA to THCV (molecular weight ratios).

## Don't confuse with

- **Total THC**: a calculated combination of acid and neutral.
- **Degradation products** (CBN, CBL): formed by oxidation or light, not by decarboxylation alone.

## Related terms

[Decarboxylation](https://genetixbay.com/knowledge/glossary/decarboxylation.md), [THCA](https://genetixbay.com/knowledge/glossary/thca.md), [THC](https://genetixbay.com/knowledge/glossary/thc.md), [Total THC](https://genetixbay.com/knowledge/glossary/total-thc.md), [Gas chromatography](https://genetixbay.com/knowledge/glossary/gas-chromatography.md), [HPLC](https://genetixbay.com/knowledge/glossary/hplc.md)

## Read more

- [Buyer beware: potency labels, strain names and other claims that don't hold up](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md)

## Sources

1. 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.
2. ElSohly MA, Slade D. 2005. Chemical constituents of marijuana: the complex mixture of natural cannabinoids. Life Sciences 78(5):539-548.
3. Hanuš LO, Meyer SM, Muñoz E, Taglialatela-Scafati O, Appendino G. 2016. Phytocannabinoids: a unified critical inventory. Natural Product Reports 33(12):1357-1392.