Arecoline is the primary active ingredient in areca nut.

Arecoline is an alkaloid found in areca nut. IARC evaluated arecoline separately because evidence about the whole nut does not automatically establish what one component can do.

Areca nut itself is a complex mixture. The carcinogenic components of this mixture have not been fully identified.

Arecoline is classified as possibly carcinogenic to humans.

IARC classified arecoline as possibly carcinogenic to humans (Group 2B) in its 2020 evaluation. Strong evidence about mechanisms relevant to cancer included genetic damage, disruption of DNA repair and oxidative stress.

This evidence came primarily from studies in human primary cells and experimental systems.

The classification differs from areca nut itself.

Areca nut, a mixture containing arecoline, is classified as Group 1, carcinogenic to humans. Arecoline was evaluated separately and classified as Group 2B. These groups describe the strength of evidence; they are not a ranking of the risk posed by particular pouch products.

For arecoline, IARC found inadequate human evidence and limited animal evidence. Mechanistic findings were central to its evaluation. This does not establish the long-term effects of a particular pouch formulation.

A hazard classification is not a measured probability.

The IARC explanation of hazard and risk distinguishes evidence that an agent can cause cancer from the likelihood of cancer at a particular level of exposure. A classification alone does not calculate that likelihood for a specific pouch formulation.

Individual risk depends on exposure amount, frequency, duration, and the specific product used. A Group 2B classification for an ingredient does not establish the measured risk profile of a particular pouch product.

This article does not establish a pouch product's composition, long-term health effects, or safety. The separate guide to pouch label units explains what information a package number needs. Nicotine pouch health risks and evidence limits concerns a different substance and should not be treated as an assessment of arecoline.