Flowers and chocolate used to be the best options for men angling for a night of passion.
But there's another way to put the spark back into their love life giving their partner's ankle a little electric shock.
Doctors have discovered a key nerve in women's bodies that can heighten their desire.
It runs from the soles of the feet to the bottom of the spine, but is most easily accessible at the ankle, where it can be zapped with electricity. Women given a small electric shock there with a tiny needle experience no more than a mild tingling sensation.
However it has been found to also boost blood supply apparently acting like a female version of Viagra. Doctors pioneering the therapy believe that it could help women whose sex lives may have lost their drive.
Tested on laboratory rats, it improved the blood flow of most within 25 minutes, and American researchers are now giving volunteer women a three-month course of weekly treatments lasting half an hour.
Tim Bruns, a biomedical engineering expert who is leading the research at the University of Michigan, said: We are really hopeful this could help many women who suffer with sexual dysfunction.
Some studies say 10 % of adult women have arousal disorder but others report it's as high as 28 %.'
Scientists became interested in the ankle therapy after women having it to cure bladder problems also reported improvements in their sex lives.
Many said they were more interested in sex. This may be because the tibial nerve running through the ankle meets the nerves which supply the pelvis within the spinal cord.
A zap to the ankle may therefore boost blood flow to a more intimate area, creating the same effect as a night of passion. It offers an alternative to drugs, which have mixed results and can have side-effects. The research on rats, published in the Journal of Sexual Medicine, showed three out of four saw significant improvements in blood flow.
The same US researchers are running a trial on 30 women with so-called arousal disorder.
The results are expected to be released later this year.
Professor Bruns said: If the stimulation is repeated multiple times, it could lead to better blood flow and stronger nerve connections to the genitalia. This would improve the symptoms of genital arousal disorder.' Up to 45 % of women are believed to have a dysfunction that lowers their sex drive.