Walk into a chemist’s and you’ll be confronted by shelves full of skin creams boasting of their anti-ageing powers. Purists and pedants (not that I know any) will object that they cannot work by definition: unless physics is badly wrong about many quite fundamental things, it is hard to see how a tub of cream could halt the flow of time.

But can they at least undo some of the symptoms of ageing, or help reverse the wear and tear that comes with ordinary life? The short answer is that, although many of the claims are based on nothing more solid than consumer surveys or celebrity endorsements, some of the ingredients in face creams have more rigorous scientific backing behind them.

Our column this week is a nice example of the risks of too much cynicism. The professionally world-weary will tell you to “follow the money” and scoff reflexively at any claims made by private companies. As a rule of thumb, you can see the attraction: the people making the claim are the ones who stand to benefit financially if you believe it.

But like all rules of thumb, it can lead you astray. Tamoxifen was developed in the 1960s by ICI, a now-defunct British drugs and chemicals company, the sort of place people have in mind when they mutter darkly about “Big Pharma”. Nevertheless, it is very effective at treating some kinds of breast cancer. Semaglutide was developed by Novo Nordisk, which sells the stuff at a handsome profit. But it works to manage diabetes and help people lose weight, exactly as the company says it does. And some of the ingredients in cosmetics got there because clinical trials have proven that they really are effective.

Scientific scepticism is definitely healthy. If you really want to know the truth, though, there’s no substitute for looking at the data—sometimes you might be surprised by what you find.

Health information (and misinformation) is also the topic of our two latest episodes of “Babbage”. In the first, we diagnose the problems of getting your health advice from the internet; in the second episode we provide a guide on how to work out who to trust.

Do you have a skin-care routine that you swear by? Let us know at wellinformed@economist.com.

A biochemistry textbook sometimes feels like essential reading when shopping for wrinkle-reducing products. Their labels list molecules like retinoids, antioxidants, peptides and exfoliating acids. The names might be familiar, but does anyone know what they do?