The capsule of compounds, based on extract of crushed grape seeds, has been hailed by celebrities such as the French actress Isabelle Adjani and Princess Caroline of Monaco, who claim that it puts a break on advancing years by combating skin damage from sun, pollution and smoking, and smoothing out wrinkles to keep them young.
The supplement, Oligomeri Pro Anthocyanidolic capsules, or OPC, is claimed to have an antioxidant effect 50 times more powerful than vitamin E and 25 times more powerful than vitamin C. It is said to work by blitzing the body with antioxidants, currently the fastest-growing sector of the health supplement market.
No disease or infirmity seems too big a challenge for antioxidants. They can, it's claimed, delay or prevent the onset of cancer and heart disease, slow down the ageing process, extend life span, boost fertility, reduce memory loss and keep the skin young. These compounds are produced by the body and also occur naturally in many foods, including broccoli, tomatoes, nut oil and spinach.
In the body, they protect cells from being attacked by free radicals, which are produced naturally by metabolising cells, and can damage DNA.
The question is whether taking supplements containing antioxidants can boost the body's capacity to fight off the ill-effects of ageing, or whether they are merely excreted - as expensive urine. Experts are still unsure.
There is also concern that much of the research work that has been done with antioxidants has been done either in the laboratory, or on animals.
"The concept is a valid one but there has not been the scientific scrutiny that they really do produce the benefits in humans that are claimed. Most of the systemic, internal studies on antioxidants have been done on animals," says Professor Nick Lowe, a dermatologist at the Cranley Clinic in London. "There you can show decreases in risks of skin cancer and other cancers with some mixtures, but I think it is rather a leap of faith to believe you are therefore going to get improvements in humans.
"We did a study when I was at the University College of Los Angeles, which lasted eight years, where we looked at using beta carotene as an antioxidant. We wanted to see if there was any reduction in skin cancer when you supplemented diets with beta carotene compared to placebo. We found no benefits. There have also been studies on bowel cancer, but to my knowledge there has not been a published study on the systemic effects of antioxidants on ageing in the human skin. Many of the activities of antioxidants are presumed from how they work in the test-tube."
As we get into our thirties and forties the levels of antioxidants, like many other things, start to diminish. It's believed that production of the enzymes that neutralise the free radicals can be encouraged by supplements, and by eating food containing antioxidants.
One man who is in no doubt about the value of taking antioxidants is Professor Lester Packer, head of the Packer Laboratory at the University of California. He says that they can both prevent disease and extend life span.
"Thousands of studies have now confirmed that antioxidants can help prevent numerous diseases and will not only enhance life, but in all probability extend it. There is overwhelming scientific evidence demonstrating that those of us who eat a diet rich in antioxidants and take antioxidant supplements will live longer, healthier lives," he enthuses.
There are scores of different types of antioxidants, but Professor Packer and his team have identified a number of key players - vitamins C and E, lipoic acid, glutathione, and a special molecule he calls COQ10.
"What we have found here is that these work together to bolster and strengthen the entire defence system. When combined they greatly enhance the activity of one another," he says.
OPC, from Laboratoires Caudelie in Paris, is designed to increase the body's levels of antioxidants by the use of grape seed polyphenols mixed with borage and primrose oil.
Many people regularly take antioxidant supplements, and many more have changed their diets to include food rich in natural antioxidants. But it is still not known whether synthetic antioxidants are as good as the real thing.
"We know how antioxidants work and from animal studies we know they are beneficial, but there is still a debate on the benefits of taking antioxidant internally to combat free radical damage. For many people the jury is till out," says John Lovell, a cell biologist.
Professor Packer, however, practises what he advocates with daily diet boosters. And that, he says, is why he is still a full-time scientist at 71.