His parents were the physician Johann Samuel Ackermann (1705-1762) and Eva Rosine Oberreuther (1722-1776), the daughter of the tanning master Paul Steinmüller.

[2] Johann attended the University of Jena at only fifteen years old and was taught there by Ernst Gottfried Baldinger.

The two relocated to Göttingen where he studied, apart from medicine, the classical sciences, as a student of Christian Gottlob Heyne.

Ackermann was promoted in 1775 to private lecturer at the medical faculty of Halle, where he lived for two years.

The main focus of Ackermann's scientific works lies in his historical studies of the medical sciences during the Middle Ages.