Drugmaker Mylan has started selling a generic version of its emergency allergy treatment EpiPen at half the price of the branded option, the cost of which drew national scorn and attracted Congressional inquiries.

The launch of Mylan’s long-promised generic alternative is expected to still generate millions of dollars in revenue for the drugmaker while also protecting its market share against current and future competition.

Mylan says it will charge $300 for the generic version of its life-saving injections, which come in a two pack.