allantoin

noun

al·​lan·​to·​in ə-ˈlan-tə-wən 

: a crystalline oxidation product C₄H₆N₄O₃ of uric acid used to promote healing of local wounds and infections

Examples of allantoin in a Sentence

Recent Examples on the Web

Rich in minerals like magnesium and calcium, the water helps hydrate and balance skin, while panthenol, allantoin, and betaine soothe and support the moisture barrier. — Christa Joanna Lee, Allure, 7 Oct. 2026

But this serum is especially great for balancing sebum levels and keeping blemishes in check thanks to its high concentration of niacinamide (15%) paired with acne-fighting zinc PCA and soothing allantoin. — Sarah Y. Wu, Glamour, 7 Oct. 2026

Its conditioning blend of sensitive skin-friendly ceramides, fatty acids, cholesterol, and allantoin helps restore the skin barrier and stave off dryness all day long. — Kiana Murden, Vogue, 25 Sep. 2026

Hyaluronic acid and allantoin add hydration and reinforce the skin barrier. — Lauren Jarvis-Gibson, Fort Worth Star-Telegram, 26 Aug. 2026

Word History

Etymology

borrowed from German Allantoin, from Allantois allantois + -in -in entry 1; so called because it was found in the allantoic fluid of cows

Note: The term was introduced by Justus von liebig in "Ueber einer neuen Apparat zur Analyse organischer Körper und über die Zusammensetzung einiger organischen Substanzen," Annalen der Physik und Chemie, 2. Folge, 21. Band (1831), p. 34.

First Known Use

1837, in the meaning defined above

Rhymes for allantoin

• aileron
• antiphon
• autobahn
• carillon
• castellan
• celadon
• cephalon
• cynodon
• denouement
• deuteron
• echelon
• epsilon

Medical Definition

allantoin

noun

al·​lan·​to·​in ə-ˈlan-tə-wən 

: a nitrogenous compound C₄H₆N₄O₃ that occurs in many organisms as a product of the oxidative degradation of purine, is often synthetically manufactured, and is used as an ingredient in various topical products (such as skin cream, shampoo, and makeup) especially to soothe irritated skin, relieve dryness, and promote healing

Note: In humans, allantoin is formed by the oxidation of uric acid and is excreted in the urine.

… a uric acid–specific enzyme that catalyzes the oxidation of uric acid to allantoin, an inert water soluble purine metabolite, thereby lowering serum uric acid.

—Gerald G. Briggs, Rheumatology News