Women like to be drunk or tipsy before hopping into bed with a partner because it makes them feel more confident, a new study has revealed.

A UK survey of 3000 women aged between 18 and 50 found nearly 50 per cent said they preferred sex after having a couple of drinks because it helped them be more adventurous.

Four out of 10 had been tipsy when sleeping with a partner for the first time, and 75 per cent of women liked to drink before having sex with their boyfriend or husband, the Australian Herald Sun reported.

The study also found women, on average, had slept with eight men but were drunk with at least five and on two occasions couldn't remember the man's name the next day.

Fourteen per cent of women in a relationship said they can't sleep with their partner without a few glasses of wine beforehand, while six per cent said they had never had sex sober.

Wellington-based sexologist Michelle Mars said it was common for Kiwi women to have a few drinks before sex, but it was important not to rely on the influence of alcohol to have a good time between the sheets.

"Alcohol lowers inhibitions generally, so it is no surprise that people drink before they have sex," said Mars.

"One or two drinks will lower your inhibitions but more than that will act as a central nervous system depressant, which is not good for sex."

What it really takes to feel good in the bedroom, Mars said, is not alcohol, but aiming to be more confident your own sexual ability and body image.

While women will drink in order to feel less self-conscious, men will almost always already think you're sexy.

"What men like and what women think men like are two very different things. Every woman has wondered, 'does my bum look big in this?' while many men have told me they love big bouncy arses.

"I think women and men can learn to be more confident about their sexuality.

"We tend to think that sex is all about how you look but there is so much more to it than that - being relaxed and confident in your sexual self is going to make you a much better lover."

Kathryn Lakeland of Femfresh, which conducted the study, told the Herald Sun the results showed women lacked confidence.

"The fact alcohol plays an integral role in their love lives shows that women are looking for a boost in their self-esteem when it comes to their bedroom antics," she said.

"But in doing so many women will be losing self-control, and this is when drunken one-night stands are more likely to occur."

* Sexologist's perfect cocktail

Sexologist Michelle Mars says when it comes to alcohol, more is definitely not merrier when paired with sex.

Mars and her business partner, Blair Bishop, recommend a drink lower in alcohol to stay relaxed without getting dehydrated or too tipsy.

"If you want to have good sex on the first night, it's better not to drink too much," said Mars. "A champagne cocktail like the following, or a lower alcohol beer will do the trick."

Michelle Mars' sexy champagne cocktail:

Put one to two tablespoons of clear, not cloudy, apple juice concentrate into the bottom of a champagne glass.

Add half a cup of soda water.

Top up with quarter cup of dry champagne.

The apple juice stops you getting that acidic feeling you get from too much alcohol, but the champagne will help you feel relaxed and slightly more uninhibited.