A crystalline compound formed in the nitrogen metabolism of many mammals (excluding primates).
A cyclic compound related to hydantoin; chemical formula: C4H6N4O3.
The active compounds are allantoin and rosmarinic acid....
Oftentimes, it is not the cortisol stimulating properties which are cited for their healing properties but some other biochemical agent such as allantoin in comfrey.
Comfrey contains allantoin, a natural substance that stimulates the growth of new skin cells.
Origin
Mid 19th century: from allantois(because it was discovered in the allantoic fluid of cows) + -in1.