What happens when you take the treatment?
This phrase loops in my head as I return to the clinic for my treatment. Ten minutes in, I trail off mid-sentence talking to the nurse ('That's the magnesium chilling you out,' she says). Afterwards I head to the hospital for more blood tests, intrigued to see what all this has done to my blood levels. The results reveal a surge in vitamin B12 (way above the lab's healthy range) and large spikes in vitamin C and zinc.
'A vitamin drip cocktail with a high dose of vitamin B12 increases blood concentration levels,' says Powers. 'But that will likely exceed the amount your kidneys can handle and you'll wee out the rest. 'In other words, such high doses are essentially pointless. As for vitamin C: 'White blood cells are saturated after taking 100-200mg orally,' says Shenkin. 'The cells don't work faster or harder because there is more of a vitamin or mineral.' Fortunately for these clinics, they don't have to answer scientists' claims, as they fall outside the Medicines and Healthcare Products Regulatory Agency's remit. Overt medical claims are policed, but promises to boost energy, immunity, weight loss or skin health are not. Alongside the unsubstantiated claims are the tantalising anecdotes of vitamin drip converts. For Kelly Marks, 42, who works in public relations in London, her first IV experience made her really relax. 'I went for a 45-minute drip and left feeling less bogged down by my worries,' she says. Emily Porter, 32, a copywriter from Devon noted the difference while running: 'I achieved a PB over 5K, which felt effortless.'
Then there are the medical professionals who, unswayed by the evidence, believe that vitamin drips do have something to offer. I asked Dr Jane Leonard, a cosmetic doctor who administers IVNT independently, why IV vitamins are superior to oral supplements. 'It's the delivery,' she says. 'A capsule has to be broken down, but IV vitamins go straight into your bloodstream, at a dose where they can have a potent effect.' Sure, but can you quantify if they're worth it? 'It's impossible to measure feeling better,' says Leonard, 'the only thing you can monitor is how you feel afterwards.'
But what if it is just a feeling? Multiple studies suggest IV therapy is primed for the placebo effect. The first clue is the cost, as the Massachusetts Institute of Technology found a higher price increases the potency of a placebo. 'The more invasive a placebo, the more effective it is, too,' adds Dr Jeremy Howick, leading placebo researcher at the University of Oxford. So what happens in your brain when you're duped by a medical placebo?
These deliver the chemical kick attributed to the treatment. My sore throat lingers for hours after the treatment and by 6pm, I'm so tired I cancel a spin class. 'You had a "low necessity belief",' explains Robert Horne, a professor in behavioural medicine at University College London. 'Because you were sceptical, the treatment probably didn't work as a placebo.' Does this idea put our IV newbies off? 'If that's the case, then I wouldn't spend the money before a 5k park run, but I'd consider it for a marathon,' says Porter.
Two weeks later I return to the lab for a second round of tests. Readings show my vitamin C has dropped to within the lab's healthy range, as expected. Both vitamin B12 and magnesium are slightly below pre-treatment levels. 'Your body is returning to homoeostasis: the level it has genetically set as its normal range for micronutrients,' says Miller. So what's my body got out of it? More concerning are my B6 levels, which, after dipping immediately following the treatment, are now over the lab's healthy threshold. 'We don't know why this happened,' says Miller - assuring me that, as a water-soluble vitamin, levels should drop down to within my normal range. My zinc levels spiked immediately and remain unusually high 10 days later.