Does NAD+ IV therapy work? The evidence is one heart failure trial

NAD+ IV therapy is a drip of nicotinamide adenine dinucleotide, a molecule every cell uses to turn food into usable energy, and longevity clinics offer it for tiredness and ageing. The human evidence for the infusion in this research comes down to one randomised trial, and it was about neither [4].

That trial enrolled 180 adults whose heart muscle had been weakened by blocked arteries, and gave them either intravenous NAD+ or a saline and glucose placebo drip for seven days on top of their usual heart medication [4].

The measure that moved was ejection fraction, the share of blood the heart's main chamber pushes out with each beat. A month later it averaged 45.4% in the infusion group against 42.4% on placebo [4]. Everyone had entered the trial below 45%, the study's cut-off for a weakened heart [4]. The gap is real. It is also about three points.

Everything else was a trend rather than a finding. Fewer people on NAD+ hit the trial's combined serious-event marker within six months, which counted death from a heart cause, heart attack, stroke or a first unplanned heart failure admission: 14.6% against 24.7% [4]. Fewer were admitted to hospital for heart failure, 13.5% against 23.6%, but those gaps were small enough that chance is a reasonable explanation for them [4]. The same goes for the blood marker that rises when the heart is strained and for the breathlessness rating patients were given. The physical size of the heart did not change at all [4].

Nothing in this evidence touches the reasons people actually book a drip. Weight, energy levels, mental sharpness and skin were not measured [4]. Reviews of the anti-ageing compounds that have reached human trials discuss NAD+ precursors, the oral building blocks the body converts into NAD+, rather than the infusion [13].

NAD+ does two jobs inside a cell. It carries electrons through the reactions that release energy from food, and it is consumed as fuel by enzymes that repair DNA and change which genes are active, among them sirtuins, proteins tied to how cells handle stress, and PARPs, which are called in when DNA breaks [7].

NAD+ levels fall with age in animals and in people, and low levels show up alongside most age-related disease: cognitive decline, metabolic disease, cancer, muscle loss, frailty [7][15]. In laboratory animals, putting NAD+ back has slowed or reversed several of those problems [7]. That chain of reasoning is what clinics are selling.

The weak link sits between the needle and the inside of a cell. NAD+ cannot be absorbed straight from food, so cells build and rebuild their own supply, and in some tissues the entire pool turns over in a matter of minutes [11]. How NAD+ and its building blocks get across into cells, and into the mitochondria where most energy is made, is still an open question in the field [11]. A higher level in the bloodstream is not the same as a higher level where it is meant to work.

In a failing heart the argument is narrower and better grounded. Damaged heart muscle cannot produce the energy it needs, and the balance between NAD+ and its spent form shifts, which alters how the genes controlling energy production behave [9]. That specific deficit is what the heart trial set out to fill [4].

One trial is one trial. It ran at a single hospital, its headline result rests on a measurement taken a month after a week of infusions, and its own authors ask for larger trials across multiple centres before anyone draws conclusions about clinical outcomes [4].

The evidence does not apply to:

• healthy adults, who were not studied at all - everyone enrolled had a weakened heart and reduced pumping strength [4]
• anyone taking a drip for energy, weight loss, hangovers or mood, none of which were measured [4]
• repeated or long-term use, since the infusions ran for seven days and follow-up stopped at six months [4]
• oral NAD+ precursors such as NMN or nicotinamide riboside, which enter the body by a different route and have their own separate trials [13]

The trial reports what happened to the heart but not what happened to the people in other respects, so this research says nothing about the safety of repeated infusions in someone who is well. Most of the remaining evidence is mechanism: reviews of what NAD+ does inside cells and in animals [7][15][11], not tests of what a drip does to a person. Those reviews are candid about it. They list among the open questions whether restoring NAD+ in ageing humans is safe, and whether it does any good [7].

Longevity clinics list NAD+ infusions next to vitamin drips, hormone panels and body composition scans, and a first appointment usually means an intake conversation followed by a cannula in the arm and a session sitting with the drip running. The service is real and easy to book. What no clinic can honestly tell you is what it will do for you, because that question has not been asked in people like you: the one trial that exists measured a heart-pumping number in patients with damaged hearts who were already on standard treatment [4]. Anyone weighing the price is choosing between a small documented effect in a disease they do not have and an undocumented one in the state they are actually in.