Chemicals and Drugs

Free Radicals

Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.

MeSH Record

Classification

Related Concepts

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See Also

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Synonyms

1 entry terms
  • Free Radical

MeSH Record

Aspects Covered

24 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, agonists, analysis, antagonists & inhibitors, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, economics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, urine.

MeSH Record

Indexing Annotation

IM GEN only; usually NIM with coord IM

MeSH Record

History Note

76(67)

MeSH Record

Previous Indexing

  • Chemistry (1966)
  • Chemistry, Physical (1966)
  • Electron Spin Resonance (1966)

MeSH Hierarchy

Tree Numbers

  1. D01w.339w
  2. D02w.389w

AMA Style

References

  1. National Library of Medicine. Free Radicals. Medical Subject Headings (MeSH). 2026. Unique ID D005609. http://id.nlm.nih.gov/mesh/2026/D005609
  2. Free Radicals. In: Wikipedia. https://en.wikipedia.org/wiki/Radical_(chemistry)
  3. Free Radicals. In: Wikidata. https://www.wikidata.org/wiki/Q185056