Pharmac says it has been caught out by the unexpectedly high demand for a contraceptive implant, and a year's supply has been exhausted within the first month.
Jadelle implants, which prevent pregnancy for five years, dropped in price from $300 to $3 in August, because government drug-funding agency Pharmac had reached a deal with Bayer Pharmaceuticals.
Pharmac deputy medical director Dilky Rasiah says there was careful planning between Pharmac, clinical experts and the supplier before the subsidy was introduced, but the surge in demand was unforeseen.
Dr Rasiah says the next shipment should be available within a month.
Bayer says it is unlikely a break in supply will lead to unwanted pregnancies.
Medical director Jan Twomey says women can continue to use other forms of contraception until new supplies are available from next month.
