A birth control gel that is applied to the skin could offer woman an alternative to the Pill, say experts presenting latest trial data.
Used once daily, it delivers hormones to prevent a pregnancy in the same way as oral contraceptives do.
Early studies show the gel is effective and well tolerated, with none of the typical side effects associated with the Pill, like weight gain and acne.
The Nestorone gel is being developed with drug firm Antares Pharma.
Researchers told the American Society for Reproductive Medicine how they hope to bring the product to market if clinical trial results continue to be positive.
The gel can be applied to the abdomen, thighs, arms or shoulders and is quickly absorbed, with no residue.
Experts say it is also suitable for women who are breastfeeding, unlike the combined Pill which can interfere with milk supply.
Dr Ruth Merkatz from the not-for-profit Population Council research centre in New York led the latest study, which involved 18 women in their 20s to 30s.
The research found the optimum dose of the gel was 3mg a day.
Over the course of seven months, none of the women using the treatment fell pregnant. Hormone studies showed the gel suppressed the production of eggs by the ovary.
Dr Merkatz said: "From this small study we found it was effective.
"It's in early stage development but if we move on, we will obviously test it in many, many more women."
The researchers say it could offer an alternative to the Pill, which is used by over 3m women in the UK alone.
Natika Halil, director of information at the Family Planning Association, said: "Any contraceptive system that increases the choice of methods available to women and helps to prevent unwanted pregnancies is welcome.
"Our research shows that there are approximately two million women using a contraceptive method that they are unhappy with, so they will benefit from improved choices and options.
"This product won't suit everyone and will only be for women comfortable (with) putting it on their skin and having their contraceptive cover that way."
Simon Blake, chief executive of sexual health charity Brook, said: "Obviously this is still in the very early stages of development but anything that can help young women has got to be a good thing.
"Clearly what young women need is more choice."