He settled in Paris in 1734 and opened a medical practice which attracted patients from the aristocracy and royal family.

With the help of Fontenelle, a distant relation, he entered the French Academy of Sciences in 1742 where his particular research interest was the application of chemistry to medicine.

Thereafter he spent increasing amounts of time at court, being granted an apartment in the Louvre and having rooms at Versailles.

In 1742 Malouin described, in a presentation to the Royal Academy, a method of coating iron by dipping it in molten zinc (i.e. hot-dip galvanizing).

In 1776 he was appointed professor at the Royal College where he occupied the Chair of Medicine until his death in January 1778 in Versailles.