It’s expensive and hurts a bit, and it sounds like the kind of thing Keith Richards would do, and for all those reasons I would never have considered a vitamin injection, until they got wildly popular. This is life as a late adopter: waiting until you’re the last person standing with the snooty remarks, then having to be the last to take them all back.

Injections have gone mass market and you can get them for £40, or a booster for £10 (getadrip.co.uk). People are getting pre-hangover group deals, where you get potassium, saline, anti-nausea, anti-acid, calcium, bicarb and paracetamol all shot into your bum before your first drink. The evidence of those who have done it (I know two) is that hangovers are dark and unknowable things, and you can never get to the root of what makes them milder or worse. Still, no one had a hangover afterwards: if it wasn’t the injection, then that is some powerful placebo.

I had the classy version at Nosh Detox, a bit more expensive (£89) and not for a hangover, because I am an adult, not a superannuated 90s slacker who won’t grow up. It was a digestion booster, a cluster of eight B vitamins (1, 2, 3, 5, 6, 7, 9 and 12). They’re good for everything: skin, hair, not having a stroke, metabolism and digestion. Immediately afterwards, I was stricken with a cold, so they’re no good for that (it’s possible I had its beginnings before I went and should have asked for the vitamin C package, but this is no time for regrets).

It doesn’t hurt like hell, but it does hurt more than, say, a yellow fever injection, or anything else that goes into your arm. That’s the only immediate effect: a minor, virtuous pain in the butt.

Now, it is incredibly hard to measure your metabolism. But a week later I was – and I know you will struggle to believe this – two kilograms lighter. It makes little sense to me, because I cannot understand the mechanism, but there it is. I have a friend who says that the vitamin D shot makes you feel as though you’ve been on holiday for a week, and that makes a bit more sense, given that D would be the vitamin you’d miss most after an eight-month winter. But all these things are so marginal, so subjective. Who truly knows how shiny their hair is? Doesn’t everyone’s skin look better when they’re in a good mood? I feel on shaky territory here, since you can’t believe or not believe in a vitamin. They simply are.

But the business of taking them in massive amounts in one go, or even taking supplements at all, rather than eating what you need in the manner of early man, requires quite a lot of faith. Yet even having never shaken the sense that I was in the land of more money than sense, it still, if digestion boosting is the euphemism I know it for – yes, I mean weight loss – seems to work.

What I learned

Junior doctors have been doing this for years, apparently – they hook themselves up to a glucose drip to get rid of a hangover.