The Center for Reproductive Rights, which brought the case, argued that there was no scientific proof that girls younger than 17 could not safely use the drug without supervision.

It said that politics had more to do with limiting access to the pill. US social conservatives have argued that widening the pill's availability would promote sexual activity among younger girls.

In 2011, the FDA said it had concluded that the "morning after" pill could be safely used by girls of child-bearing age.