Popular contraceptive pill Levlen ED is being rationed amidst fears of a shortage.
The government's drug-buying agency Pharmac confirmed it was "working ... to manage a supply issue" of the birth control pill.
"The supplier has some stock, but there is a risk of a shortage prior to re-supply in late March," Pharmac director of operations Lisa Williams says.
Pharmac has requested the pill be rationed and dispensed in monthly amounts rather than three-month supplies, to ensure patients have "sufficient" supply.
Lisa says Pharmac had "several" safeguards in place to ensure medicine was supplied to New Zealand.
Its contracts with suppliers require it to hold a minimum of two months' stock, she says.
New Zealanders faced a similar shortage in December 2017, when stocks of Ava 30ED and Levlen 30ED were affected.