The nation’s health secretary says young teenagers cannot buy the Plan B morning-after pill without a prescription.

It’s a surprise move by Kathleen Sebelius overruling her own experts, who were preparing to let it be sold on drugstore shelves like condoms.

The pill can prevent pregnancy if taken soon enough after unprotected sex. Currently, only those 17 or older can buy Plan B One-Step without a prescription, if they show a pharmacist proof of age.