The approval is subject to Mylan’s divestiture of several products after the consummation of the offer.
Mylan is offering $75 in cash and 2.3 ordinary shares for each Perrigo share. Mylan officially started its formal offer in September this year.
Mylan agreed to sell the rights and assets related to seven generic drugs in order to settle FTC charges that its proposal to buy Perrigo would be anticompetitive.
The settlement requires Mylan to sell the drugs to New Jersey-based pharmaceutical firm Alvogen Group.
Mylan executive chairman Robert Coury said: "We are delighted to have received FTC clearance, making our offer for Perrigo now unconditional other than the one final step, which now rests solely in the hands of Perrigo shareholders."
Perrigo has however called the Mylan proposal inadequate. Its investors have until 13 November to accept the offer.
Headquartered in Ireland, Perrigo manufactures over-the-counter products and supplies infant formulas for the store brand market.
Mylan manufactures and markets about 1,400 different products to retail, wholesale, government and institutional customers.
The company, which employs about 30,000 people, markets products in around 145 countries and territories.