What does “Irradiation” mean?

Treatment of cannabis material with ionising radiation to reduce microbial contamination.

Irradiation in plain English

Treatment of cannabis material with ionising radiation to reduce microbial contamination.

Cannabis flower is a plant product that can carry moulds and bacteria, which matters greatly for patients whose immune systems are compromised. Irradiation is a standard decontamination method used across the food and pharmaceutical industries.

It does not make the product radioactive. There is debate about whether it alters terpene content, and correspondingly little clinical evidence that any such change affects outcomes.

Frequently asked questions

What does irradiation mean?

Treatment of cannabis material with ionising radiation to reduce microbial contamination.

Sources and further reading

Every factual statement on this page is drawn from the following public sources. Links open in a new tab and are not affiliated with Flora House.

  1. NICE guideline NG144: Cannabis-based medicinal products
  2. NHS: Medical cannabis (and cannabis oils)
  3. MHRA: The supply, manufacture, importation and distribution of unlicensed cannabis-based products for medicinal use

Patient guide · Written by the Flora House editorial team · Last reviewed: 8 September 2026