The government has rejected over-the-counter sales of morning-after birth control, for now.
The Food and Drug Administration cited concern about young teens' use of the pills.
The FDA has been under intense political pressure from both sides on whether to lift the prescription requirement for emergency contraception.
Conservatives contend that could encourage unsafe sex.
Backers argue that easier access to the pills could prevent thousands of abortions.
The FDA says there isn't yet proof that teens younger than 16 could safely use the pills without a doctor's guidance.
The government has left the door open for Barr Laboratories to try again.
It must provide data showing young teens could use the pills safely without a prescription or offer details on how the product could be sold over-the-counter and with prescriptions for those 16 and under.