He took the name Hoppe-Seyler when he was adopted by his brother-in-law, a grandson of the famous theatre principal Abel Seyler.

[4][5] In 1858, he married Agnes Franziska Maria Borstein, and they had one son, Georg Hoppe-Seyler, who became a professor of medicine in Kiel.

[6] His numerous investigations include studies of blood, hemoglobin, pus, bile, milk, and urine.

He also recognized the binding of oxygen to erythrocytes as a function of hemoglobin, which in turn creates the compound oxyhemoglobin.

In 1877, he founded the Zeitschrift für Physiologische Chemie (Journal for Physiological Chemistry), and was its editor until his death in 1895.