N-terminal glutamic acid and glutamine residues can spontaneously cyclize to become pyroglutamate, or enzymatically converted by glutaminyl cyclases.

In living cells, it is derived from glutathione through the action of an enzyme, γ-glutamyl cyclotransferase.

[5] Increased levels of pyroglutamic acid in the blood, leading to excess in the urine (5-oxoprolinuria), can occur following paracetamol overdose, as well as in certain inborn errors of metabolism, causing high anion gap metabolic acidosis.

It has low toxicity and is not a skin irritant, but its use in products is limited by a high price.

In a preclinical study, additional pharmacological properties of pyroglutamic acid were revealed such as anti-phosphodiesterase type 5, anti-angiotensin-converting enzyme, and anti-urease activities.