Then there's Chantecaille's Nano Gold Energising Cream (top, second from right, HK$4,200 for 50ml), which says it uses nanotechnology to deliver the anti-ageing powers of pure gold and silk at a cellular level.

And if you really want to splash out, there's ReVive's anti-ageing serum Peau Magnifique (top left, HK$11,000 for one month's supply), which uses enzymes that require molecular biology techniques to produce.

The ultimate in pricey potions could be La Prairie's Jewelled Skin Caviar Luxe Cream, at HK$18,000 for a 50ml limited-edition version encrusted with Swarovski crystals. Granted, you're paying extra for the crystals (the regular one is HK$3,000 for 50ml), but it still makes the original cult cream La Mer's Creme de La Mer (HK$1,900 for 60ml) seem like a bargain.

Not to be outdone, La Mer's The Essence (top, second from left) sells for HK$18,000, for just 21 days' supply. It is said to contain a higher concentration of the original cream's 'miracle broth' which takes up to four months to distil.

To keep things exclusive, La Mer does not sell The Essence at its counters. The company's senior marketing executive, Maggie Ho Wing-yan, says: 'If a customer requests the product, we have a one-on-one presentation with them. They will be shown a video so that they understand the product. This is because we don't want customers to make impulsive purchases.'

Needless to say, they have a waiting list for The Essence, which includes 'quite a few' males, says Ho. 'The economy is booming and a lot of our customers can afford to buy products that are good quality to improve their skin. But if they cannot see improved effects they will quickly shift to another brand.'

She's not overly concerned about the competition.

'A lot of brands are now targeting the luxury market. But certain brands, which have never traditionally produced luxury creams, are now producing a cream that costs thousands. Our customers say they don't believe their claims because they don't think these brands have the technical support to produce such luxury products.'

So, do the pricey potions work? That depends on whose point of view you're considering, says dermatologist Henry Chan Hin-lee. 'Most skin-care products don't have evidence-based support to back up their claims,' says Chan.

'In dermatology, for a product to be considered effective, it needs to have data published in a peer-reviewed journal. But many brands won't release studies, even if they're performed. This is because if the efficacy is very good then the FDA (The US Food and Drug Administration) may deem it to be a drug and the company would have to apply for a drug licence.'

He scoffs at companies who claim they have done tests based on a sample size of 10 or 12 people which, he says, would never be taken seriously by any scientific journal. The other problem is that the concentrations of the ingredients are not known.

'Alpha and beta-hydroxyl acids, antioxidants and retinols have been proven to help reverse ageing and they're in many cheaper products that work well. Botox or laser treatments cost substantially less than the more expensive creams and total laser resurfacing (which can take years off your face) comes at a comparable price of around HK$18,000,' says Chan.

'On the whole, there is not enough medical evidence to support or discourage the use of more expensive anti-ageing creams.'

Perhaps one way to find out if an expensive cream is worth the extra cost is to apply it to one half of your face for a month, while using a good quality moisturiser on the other half. If you can see the difference, then it might be worth it.