CHICAGO — Don't expect to see morning-after pills for all ages on drugstore shelves anytime soon. A federal appeals court decision allowing girls of any age to buy emergency contraception without a prescription won't immediately change access.

Labels first need to be revised to remove age restrictions, and the government could file another appeal to block moving the products from behind pharmacy counters.

Doctors, reproductive health specialists, manufacturers and pharmacists struggled Thursday to make sense of the appellate ruling that allows the original two-pill version of emergency contraception to be sold immediately without restrictions. Theoretically that means girls of any age could buy the pills without a prescription and without providing identification — just like aspirin, ointments and most other over-the-counter medicines.

But the ruling doesn't lift restrictions on newer one-pill versions, which means pharmacists and pharmacy clerks will have to be clear on the differences among five or so available versions.

Some basic questions and answers:

Q: How quickly will there be a change?

A: No one knows. The government has two weeks to file another appeal. Labels for pills affected by the ruling currently restrict over-the-counter sales to girls 17 and older. Younger girls need to have a prescription.

Q: What are pharmacies and manufacturers doing?

A: Pharmacies and manufacturers said Thursday they were reviewing the ruling. Manufacturers could seek label changes, or the Food and Drug Administration could reach out to manufacturers to speed the change. They could also try to bypass the FDA by relabeling and shipping the drugs with a copy of the court order.

Q: Didn't the FDA recently rule on morning-after pills?

A: Yes, the agency announced last month that one brand — Plan B One-Step pills — could be sold without a prescription to those 15 and older. The manufacturer, Teva Women's Health, plans to begin those sales soon. This week's court ruling won't change that. Also, against objections from conservatives, the FDA had planned to remove age restrictions on over-the-counter sales for emergency contraceptives two years ago. But Health and Human Services Secretary Kathleen Sebelius overruled that decision in late 2011.

Q: Who uses morning-after pills?

A: The biggest users are women in their early 20s. A government report earlier this year said 14 percent of women aged 15 to 19 who've had sex have ever used emergency contraception, versus 23 percent of those aged 20 to 24. Only about 13 percent of teens have had sex by age 15, according to data from the Guttmacher Institute, a nonprofit group that focuses on reproductive issues.

Q: What's available and how much does it cost?

A: There are several one-pill versions in the U.S.; the only two-pill version still being made is a generic, according to reproductive rights groups. Costs for one- and two-pill versions are generally around $30 to $50, with generics at the lower end of that range.

Q: What's the advice for teens?

A: To prevent pregnancy, the American Academy of Pediatrics recommends using condoms plus birth-control pills or IUDs, or abstinence. The academy also endorses morning-after pills, but they don't work quite as well — about 90 percent effective. The American College of Obstetricians and Gynecologists says the IUD and other implants are the most effective way for teens to avoid pregnancy, and says both are safe and nearly 100 percent effective.

Q: What's the history behind the court case?

A: A federal district judge in New York ruled in April in favor of a reproductive rights group's lawsuit seeking over-the-counter access without age restrictions for emergency contraceptives. The Department of Justice appealed and a federal appellate court is considering that objection. The government sought to block over-the-counter sales while the appeal is being considered, but a three-judge panel rejected part of that request on Wednesday.

Q: How does the emergency contraception work?

A: Pills affected by the ruling contain progesterone, the same hormone found in many birth control pills, but at higher doses. They are to be used as soon as possible within 72 hours of unprotected sex. The two-pill version was initially recommended to be taken 12 hours apart; it was later determined that taking them simultaneously was easier and as effective. The pills block ovulation and fertilization of an egg.

Q: How many of these pills are sold?

A: Sales for the first four months of this year: Levonorgestrel (progestin pills): $2.7 million; Plan B One-Step: $22.1 million; Next Choice 1 Dose: $35.6 million; My Way one pill: $76,000. That's according to IMS Health, a health data firm.