Scientists have designed a novel long-acting contraceptive that can be self-administered by women using a painless microneedle skin patch.

The research, published in the journal Nature Biomedical Engineering, may pave the way for a new family planning option, particularly in developing nations where access to healthcare can be limited.

Long-acting contraceptives now available provide the highest level of effectiveness, but usually require a healthcare professional to inject a drug or implant a device.

Short-acting techniques, on the other hand, require frequent compliance by users and therefore are often not as effective.

In animal testing, an experimental microneedle contraceptive patch provided a therapeutic level of contraceptive hormone for more than a month with a single application to the skin.

When the patch is applied for several seconds, the microscopic needles break off and remain under the surface of the skin, where biodegradable polymers slowly release the contraceptive drug levonorgestrel over time.

Originally designed for use in areas of the world with limited access to health care, the microneedle contraceptive could potentially provide a new family planning alternative to a broader population.

Long-acting contraceptives are now available in formats such as patches that must be worn continuously, intrauterine devices (IUDs) that must be placed by trained healthcare professionals, and drugs injected with hypodermic needles.

If the microneedle contraceptive patch is ultimately approved for use, it could become the first self-administered, long-acting contraceptive that does not involve a conventional needle injection, researchers said.

Like other long-acting contraceptive techniques, the microneedle contraceptive patch would disrupt the menstrual cycles of women using it.

Testing with rats evaluated only the blood levels of the hormone and did not attempt to determine whether it could prevent pregnancy.

The researchers aim to develop a patch that could be applied once every six months.