When Megumi Ota needed the morning-after pill in Japan, she couldn't get a prescription in time under a policy activists call an attempt to "control" women's reproductive rights.

"I wanted to take it but couldn't over a weekend," when most clinics are closed, she told AFP.

Unable to arrange an appointment in the 72 hours after sex when the drug is most effective, "I just had to leave it to chance, and got pregnant."

Emergency contraception cannot be bought without a doctor's approval in Japan and is not covered by public health insurance, so can cost up to US$150.

It's also the only medicine that must be taken in front of a pharmacist to stop it being sold on the black market.

Abortion rights are just as restrictive, campaigners say, with consent required from a male partner, and a surgical procedure the only option because abortion pills are not yet legal.

A government panel was formed in October to study if the morning-after pill should be sold over the counter, like in North America, most of the EU and some Asian countries.

But gynaecologists have raised concerns, including that it could increase the spread of diseases by encouraging casual, unprotected sex.