First, shave your body. Then immerse yourself in turpentine. And when the stinging stops, allow leeches to feast on your blood.

It sounds like a particularly refined form of torture. But Demi Moore swears by it, as a way of looking healthy and far younger than her 45 years.

The secret, says Miss Moore, is an extremely alternative beauty therapy.

Scroll down for more...

Sucker: During an interview with David Letterman yesterday, Demi Moore revealed she is a fan of 'leech therapy'

In New York to promote her new film Flawless, Moore told U.S. talk show host David Letterman: "I feel like I've always been someone looking for the cutting edge of things that optimise your health and healing.

"I was in Austria doing a cleanse and part of the treatment was leech therapy. These aren't just swamp leeches though - we are talking about highly trained medical leeches.

"These are not some low-level scavengers - we're talking high-level blood suckers."

Miss Moore, whose husband Ashton Kutcher is only 30, said she went to the leech doctor to "detoxify my blood".

Leech therapy has a long history - ancient Egyptian doctors once considered them a cure-all.

Today, they are sometimes used in plastic and reconstructive surgery to assist in the reattachment of severed body parts.

"They have a little enzyme that when they are biting down in you it gets released in your blood and generally you bleed for quite a bit - and your health is optimised.

"It detoxifies your blood - I'm feeling very detoxified right now.

"I did it in some woman's house lying on her bed. We did a little sampler first, which is in the belly button.

Scroll down for more...

Detox: Demi received the treatment as part of a 'cleanse' while visiting Austria

"It crawls in and you feel it bite down on you and you want to go, 'You b*****d'. Then you relax and work on your breathing just to kind of relax.

"You watch it swell up on your blood, watching it get fatter and fatter - then when it's super drunk on your blood it just kind of rolls over like it's stumbling out of the bar."

Miss Moore explained how she prepared herself for the leeches. "You have to do a turpentine bath first - that's part of the therapy," she said.

Thirsty: the actress says the little critters left her feeling 'revitalized'

"The other thing I found out is that leeches don't like hair so if you are hairy be prepared to do some shaving or waxing - they much prefer a Brazilian."

The actress said she is convinced the therapy worked and she will be returning to Austria for more sessions.

"You first feel worse then you feel better. But I'm going back - I only got four leeches and I feel a bit cheated."

Another key to Miss Moore's youthful looks, which she failed to mention on the show, is the £220,000 she spent on a head-to-toe makeover five years ago.

She was reported to have had liposuction to her hips, thighs and stomach, breast implants, brow lifts, collagen injections, knee surgery, a breast lift, her teeth veneered and laser whitened, chemical skin peeling and a long course of exercise coaching.

The actress became famous in the 1990s with films including Ghost, in which she starred opposite Patrick Swayze, and Indecent Proposal with Woody Harrelson and Robert Redford.

She and Willis, now 53, split in 1998 after 11 years together. They have three daughters, Rumer, 19, Scout, 16, and Tallulah Belle, 14.

Miss Moore and Kutcher, star of movies such as Dude, Where's My Car?, married in September 2005.