[ uh-lan-toh-in ]
/ əˈlæn toʊ ɪn /

noun Biochemistry, Pharmacology.

a white powder, C4H6N4O3, produced by oxidation of uric acid and the major excretory product of purine degradation in many vertebrates: used medicinally to heal skin ulcers and in lotions, lipsticks, etc., for its soothing effect.

Origin of allantoin

1835–45; allanto(is) + -in2; so named because it is found in the fluid of the allantois Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for allantoin

/ (ˌælənˈtəʊɪn) /


a substance derived from the secretions of snails and contained in some plants, used in skin care products and valued for its soothing properties

Word Origin for allantoin

C19: from allantois
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for allantoin

[ ə-lăntō-ĭn ]


A substance present in allantoic fluid, amniotic fluid, and fetal urine.
A crystalline oxidation product of uric acid produced in vertebrate purine metabolism and used medicinally to promote tissue growth.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.