Lisa Markwell: A boob job in a jar? What a waste of science

I'm no scientist, but a cream that increases your bust size.... Come on, how gullible do you think we are? As Rodial Boob Job, which costs £125 for a 100ml pot, goes on sale, there will be some women queuing up to hand over the cash, possibly inspired by the photograph of pneumatic Scarlett Johansson accompanying the news stories. We're told she's a devotee.

I can't say I've spent a great deal of time studying Ms Johansson's form, but I'll bet her enviable figure is down to youth rather than Rodial's products.

The manufacturers of Boob Job claim that if you rub this cream into the chest in a circular motion for 56 days, your bust size will go up half a cup. What I say is: if you rub any cream – up to and probably including goose fat – into your chest for six weeks, you'll see firmer skin and fewer wrinkles. Myrrh resin and wheat proteins, indeed.

Beauty products with wild claims are nothing new – "Bathe in ass's milk and get skin like a baby's bottom"; "Try our new lead and arsenic face powder for a complexion like a cadaver... because you're worth it". But it's surprising that women in their droves are still willing to pay a lot of money for unproven products.

My girlfriends love to play "spot the disclaimer" on beauty product advertising. When the voiceover says something like "Voted the most trusted eye cream", quickly look for the tiny writing at the bottom of the screen that says "... by 70 per cent of a sample group of 37 women". It's only up there for a split-second.

Then there's the story of the soap factory from which economy brand-less bars are dispatched, along with "designer" bars. The ingredients are the same, the difference is only in the final buffing-up and embossing of the posh one.

Busts are in fashion, which may further boost Boob Job's ubiquity. Many of us are mightily tired of hearing about how we should "get the Mad Men look" (big bosoms, tiny waist, a bit of a hip) when the overwhelmingly prevalent body is pear-shaped. Emulating Mad Men's Joan Holloway is simply not an option, but there will be those willing to spend north of a hundred quid on the promise of a perky Sixties-style décolletage to try and offset the broadness of beam.

Any woman who has admired another's skin/hair/figure will know that these things are determined, to an enormous degree, by genetics – and nothing to do with lotions, potions or dynamic exercise bands.

I worked for a glossy women's magazine a few years ago when a lip gloss with "plumping" action was launched, promising pillowy lips without having to resort to injections of cosmetic filler (a favourite procedure of various television personalities). We all smeared it on with gay abandon only to realise too late that it a) stung and b) resulted in a swollen effect hitherto obtained by getting smacked in the mouth. And that's never been a good look.

It appears that an ingredient has been developed in a laboratory somewhere which swells the skin, and it is being utilised in beauty products. As cosmetic surgery becomes commonplace, so develops an increasing market in products that promise similar results without having to resort to the knife.

It's all rather dispiriting when what would make women feel a lot better about their bosoms would be more laboratories devoted to research into eradicating breast cancer. But then, that's not terribly glamorous, is it?