"The total workforce is expected to be reduced by approximately 1,300 employees before the end of 2018 and the majority of these reductions have been implemented as of 1 November 2018," the Danish company said in a statement.
The costs related to the layoffs helped push down the company's earnings, with net profit sliding 8 percent year-on-year to 9 billion kroner (€1.2 billion, $1.4 billion) in the third quarter. Sales rose by 4.3 percent to 27.6 billion kroner.
The firm said the restructuring aimed "to accelerate the expansion and diversification of its pipeline and to enable increased investment in transformational biological and technological innovation."
Novo Nordisk alone supplies nearly half of the insulin to diabetes sufferers across the globe.
Rising obesity has led to a surge in diabetes cases, but the costs of some of the new treatments have posed difficulties for the firm, particularly in the United States where some private insurers have balked at the price tags.
Novo Nordisk said its insulin sales fell by 8 percent in local currencies in North America in the first nine months of the year, noting lower prices due to rebates.