[6] In aqueous solution, this monohydrate exists in equilibrium with a hemiacylal dimer form:[7] In isolation, the aldehyde structure has as a major conformer a cyclic hydrogen-bonded structure with the aldehyde carbonyl in close proximity to the carboxyl hydrogen:[8] The Henry's law constant of glyoxylic acid is KH = 1.09 × 104 × exp[(40.0 × 103/R) × (1/T − 1/298)].

[16] Glyoxylate is produced via two pathways: through the oxidation of glycolate in peroxisomes or through the catabolism of hydroxyproline in mitochondria.

While at first considered a waste of energy and resources, photorespiration has been shown to be an important method of regenerating carbon and CO2, removing toxic phosphoglycolate, and initiating defense mechanisms.

[23] One of the key conditions of diabetes pathology is the production of advanced glycation end-products (AGEs) caused by the hyperglycemia.

In a study, glyoxylate levels were found to be significantly increased in patients who were later diagnosed with Type II diabetes.

[23] The elevated levels were found sometimes up to three years before the diagnosis, demonstrating the potential role for glyoxylate to be an early predictive marker.

Glyoxylate is involved in the development of hyperoxaluria, a key cause of nephrolithiasis (commonly known as kidney stones).

[7] In general, glyoxylic acid undergoes an electrophilic aromatic substitution reaction with phenols, a versatile step in the synthesis of several other compounds.

The sequence of reactions, in which glyoxylic acid reacts with guaiacol the phenolic component followed by oxidation and decarboxylation, provides a route to vanillin as a net formylation process.

[28] Glyoxylic acid enters the composition of cosmetic creams used for “Brazilian” hair-straightening treatment.

Glyoxylic acid is used in cosmetic products in replacement of formaldehyde to avoid skin irritation by this latter.

[29] After transcutaneous absorption, glyoxylic acid contained in hair-strengthening creams causes calcium oxalate nephropathy.