Would you use a patch of 100 tiny needles over the contraceptive pill?

A patch filled with tiny needles can inject up to 60 days’ worth of hormonal contraceptives. Women could apply the patch at home, making it a potentially hassle and pain-free alternative to injections or implants.

Mark Prausnitz at the Georgia Institute of Technology and his colleagues created the patch, which contains 100 microneedles, each around half a millimetre long and 0.01 millimetres wide at the tip. When the patch is applied, the needles come off the patch, break the skin and sit under the surface.

Each needle contains a small dose of the hormonal contraceptive levonorgestrel, which is slowly released as the microneedle degrades over a period of up to 60 days.

Normally, long-acting contraceptives need to be administered by professionals, but this could be self-administered, says Prausnitz. The patch could be used once a month, rather than every day like with the pill.

The team tested the patch on rats and found that more than 90 per cent of the microneedles detached after 50 seconds on average.

To see how well the patch would work with people, the team tested it on 10 women using a placebo patch that didn’t contain any levonorgestrel. The microneedles detached from the patch to enter the body just as well as they did in rats.

All the women said they would opt for the patch over a monthly injection of hormones, while only one would stick with a daily pill.

Chenjie Xu at Nanyang Technological University, Singapore, says the next step should be to test a version of the patch with a hormonal contraceptive in people. It is important to know if the work in rats translates to humans, he says.