Cow snot could prevent AIDS and herpes.
A lubricant that is made from bovine mucus has been proven to beat sexually transmitted infections as human cells treated with the gel were up to 80 per cent less likely to get infected with HIV and herpes.
The researchers, from the KTH Royal Institute of Technology in Sweden, said that their "promising" creation could slow the spread of STIs if the product becomes widely available.
The main component of cow mucus is a protein called mucin which is believed to have antiviral properties.
The research team was led by the researcher Hongji Yan, who extracted mucus from cow salivary glands before turning the substance into a lubricant.
Yan said that the gel can help people "take greater control of their sexual health".
He said: "It could offer protection when condom protection is not an available option, or even as back-up protection in case of condom failure or incorrect use. It could be used in both female-to-male sex and male-to-male sex."