In 1906, two chemists in London were studying juice pressed from yeast when they noticed something odd. A substance in it, sturdy enough to survive heating, made sugar ferment faster. They called it cozymase. One of them, Arthur Harden, later shared a Nobel Prize for the fermentation work. The longevity molecule, in other words, was first spotted in the chemistry of bread and beer.

We call it NAD+. Your cells use this coenzyme to turn breakfast into energy, and it helps run their DNA repair crews. Levels fall with age in animal studies. A century after the yeast, the molecule has become the unofficial mascot of longevity culture, complete with its own clinics and influencers. You can buy more of it three ways, and each comes with a very different receipt.

Line the receipts up against the research and the order flips. The cheapest route has the most human evidence that it raises NAD+, and the trendiest has almost none.

NAD+ IV bag, nasal spray and supplement bottle lined up on receipts, comparing NAD+ IV vs supplement costs

The short answer: In the NAD+ IV vs supplement comparison, the capsule has the stronger human evidence. Oral nicotinamide riboside (NR) has several placebo-controlled trials showing it raises NAD+ in the blood. IV NAD+ rests on one small pilot that measured plasma, and NAD+ nasal spray has no published trial in healthy people. No route has shown it slows ageing.

  • University of Colorado Boulder trial: daily NR raised NAD+ in white blood cells by about 60% over six weeks
  • A 2019 Australian IV pilot gave 11 men NAD+ over six hours; plasma levels stayed flat for two hours
  • Yearly cost: about $6,000 for monthly $500 drips in Vaughan, Ontario, against about $607 for NR capsules
Route Human evidence it raises NAD+ How sure are we What nobody has shown yet
IV drip One small pilot in men, measuring blood plasma Emerging Whether any of it reaches your cells, and for how long
Nasal spray No published trial in healthy people Unsupported Absorption, dose and effect
Capsule of a precursor (NR or NMN) Several placebo-controlled trials; NR has the most Established for blood levels (NR); Emerging (NMN) That a higher blood level changes how you feel or age

Receipt one: a $500 sofa afternoon. Does an NAD+ IV beat a supplement?

For that price, a mobile IV company in Vaughan, Ontario, will come to your home with a single bag of NAD+. There are package deals if one afternoon is not enough. You settle into the sofa with a cushion under your elbow, the television on mute, while the drip starts very slowly.

Woman resting on her living-room sofa during an at-home NAD+ IV drip as a nurse adjusts the line

Slowly is the point. A clinic in Toronto and Oakville warns on its own website that NAD+ run too quickly "can cause temporary chest tightness, flushing, or nausea." You rarely find a sentence like that on a menu of luxury treatments.

What the bag does once inside comes mostly from one Australian pilot. Eleven men received NAD+ over six hours. For the first two, their plasma levels did not move, because the body cleared it as fast as it arrived. By the end, levels had climbed, and some of the surplus was already leaving in their urine.

The pilot measured a spike in the blood and never checked whether any of it reached the cells you are paying to reach.

Receipt two: US$125 a month for your nose

This receipt arrives by email from a US telehealth company. You answer an online questionnaire between meetings, a provider signs off, and a compounded NAD+ nasal spray is posted to your door for use once or twice a day. The pitch is that the nose offers a shortcut to the brain, and with it, focus.

White laboratory mouse sniffing a small NAD+ nasal spray bottle on a lab bench

Its fine print is more candid than the pitch. In the seller's own words, the FDA has not reviewed or approved compounded products "for any use for safety, efficacy, or quality."

A PubMed search this month found no published trial of NAD+ nasal spray in healthy people. The closest study, from July, used mice whose sense of smell had been wiped out with a zinc compound. Researchers sprayed NAD+ up their noses, and their sense of smell improved. That is excellent news for anosmic mice and no news at all about your 3 p.m. slump.

Receipt three: which NAD+ supplement has the evidence?

The last receipt is the dullest. A bottle of 90 nicotinamide riboside (NR) capsules costs $151.79 at Viva, or $50.60 for a month at one a day. There is no nurse, no subscription and no mouse, only a bottle that lives in the cupboard beside the good olive oil.

These capsules rarely contain NAD+ itself. They carry a precursor, a smaller building block that your cells assemble into NAD+ on site. NR has the longest trial record. Its close cousin NMN has fewer trials, and at least one of the main ones was funded by companies that make it.

At the University of Colorado Boulder, healthy adults in late middle age and beyond, postmenopausal women among them, took NR daily for six weeks and a placebo for another six. NAD+ inside their white blood cells rose by about 60%. They took more than the label's one capsule a day, which is a conversation for your doctor before you copy them. A higher number on a blood test is a real result, and it still says nothing about your energy on a Tuesday afternoon.

Tru Niagen nicotinamide riboside 300 mg capsules

TRU NIAGEN 300 mg (90 capsules), $151.79

Niagen, the patented form of nicotinamide riboside, in one capsule with breakfast. It is the least glamorous receipt in this story and the one you can keep paying without wincing.

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A looser, cheaper bet sits on the same shelf, pairing a little vitamin B3 with plant compounds.

Younited NAD Activator capsules with resveratrol, quercetin and niacin

YOUNITED NAD Activator (90 veg capsules), $61.49

Niacin, a form of vitamin B3, with resveratrol, pterostilbene, apigenin and CoQ10, taken three capsules with a meal. Buy it as a broad antioxidant formula with a B3 backbone, since this exact blend has not been put through a trial of its own.

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The year-end statement

Add up twelve months of NAD+ IV versus supplement costs. Monthly drips at the Vaughan price come to $6,000 a year, and four bottles of capsules come to $607. No route has yet shown, in a long-term human trial, that it slows ageing. Until one does, the difference buys a great many afternoons on your own sofa with the television on mute.

Kitchen cupboard shelf holding an NAD+ supplement bottle beside olive oil and a sourdough loaf

This article is general information and does not replace advice from your doctor or pharmacist.

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Frequently asked questions

Does nicotinamide riboside cause flushing like niacin?

Not in the largest dose-finding trial. Among 140 healthy overweight adults taking up to 1,000 mg of NR daily for eight weeks, nobody reported flushing, and side effects were no more common than on placebo. Its authors included consultants to ChromaDex, which makes Niagen.

Will NR give me more energy?

Nobody has shown that it does. A University of Birmingham team gave twelve older men 1 g of NR daily for three weeks, then took muscle biopsies. NAD+ by-products rose in the muscle, but the mitochondria worked no better than on placebo.

Can I take an NAD+ supplement with other medication?

Check first. The Younited formula's label asks you to consult a practitioner if you take prescription drugs, and advises caution with blood thinners or blood pressure medication. It also says to avoid it before surgery and during pregnancy or breastfeeding.

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