Recombinant insulin-based products are the number 3 best selling class of biologics, with total sales in 2005 estimated at $7.21 billion.

Recombinant human Insulin, made by extracting the gene for insulin from a human cell, inserting it in yeasts or bacteria and growing them in a vat, have been on the market for more than two decades.

In newer insulins, called recombinant human insulin analogs, the genetic material is modified to make the drugs faster acting or longer acting.

The leading recombinant human insulins are: