NAD+
NAD+ UK: Injections, IV Drips, NMN, NR and What the Evidence Shows
The plain-English guide to NAD+: what it is, why scientists link it to ageing, and what the human evidence actually shows for NAD+ injections, IV drips and the supplements NMN and NR.
Important before you read this guide
NAD+ is a natural molecule that every cell in your body needs. That part is not in doubt. What is in doubt is whether NAD+ drips, injections or supplements do what they are sold to do. We could find no NAD+ product licensed as a medicine in the UK for anti-ageing, energy or longevity. This guide explains the science and the evidence. It is not medical advice, a dosing guide or a recommendation to use any NAD+ product.
What is NAD+?
NAD+ stands for nicotinamide adenine dinucleotide. It is a coenzyme, which means a helper molecule that other parts of the cell need in order to work. It is found in every living cell.
Your body makes NAD+ itself, mainly from vitamin B3 (niacin) in foods such as meat, fish, eggs and wheat flour, and also from tryptophan, an amino acid in protein. The NHS explains that vitamin B3 helps the body release energy from food.
According to a 2021 review in Nature Reviews Molecular Cell Biology, NAD+ has two main jobs:
- Energy. When your cells break down food, NAD+ picks up electrons and becomes NADH. NADH carries them to the mitochondria, the parts of the cell that make energy. NAD+ and NADH are simply two forms of the same molecule, switching back and forth.
- Cell maintenance. Enzymes involved in repairing DNA and controlling genes, including the sirtuins and PARPs, use NAD+ up as they work. So the body has to keep making more.
NAD+ is often sold alongside peptides and searched for as a “NAD+ peptide”. It is not a peptide. Peptides are short chains of amino acids, as our guide to peptides explains. NAD+ is a different kind of molecule, built from vitamin B3 and building blocks similar to those in DNA and RNA.
Why is everyone talking about NAD+?
Two things came together. First, in the 2010s, laboratory studies found that raising NAD+ in older mice improved several measures of their health. Some of these became high-profile papers about ageing.
Second, a fast-growing wellness industry now sells NAD+ in many forms: IV drips, injections, nasal sprays, patches and capsules. These are often marketed for energy, focus, recovery, skin and “longevity”, and promoted heavily on social media.
The science of NAD+ is genuinely important. But the commercial claims go much further than the human evidence. The rest of this guide explains where that gap is.
Does NAD+ decline with age?
Probably, in some parts of the body. But the human evidence is less clear-cut than adverts suggest.
The strongest evidence comes from animals. In people, the studies are smaller. A 2015 brain-scan study of healthy volunteers found lower NAD+ and higher NADH in older brains. A 2019 study of blood samples from people aged 20 to 87 found lower NAD+ levels in older people’s blood plasma.
However, a 2020 review by University of Pennsylvania researchers points out that human data are limited, and that measuring NAD+ accurately in specific tissues and cells is still difficult. Scientists also do not yet know how low NAD+ has to fall before it actually causes problems.
So “NAD+ falls in some tissues as we age” is a fair summary. “Your NAD+ has halved and needs topping up”, which you may see in adverts, goes well beyond the evidence.
NAD+, NMN and NR: how are they different?
These three names are often used as if they mean the same thing. They do not.
- NAD+ is the molecule your cells actually use. It is sold as IV drips, injections, patches, nasal sprays and capsules.
- NMN (nicotinamide mononucleotide) is a building block, or “precursor”, one step away from NAD+. Your cells turn it into NAD+. It is sold as a supplement.
- NR (nicotinamide riboside) is another precursor and a form of vitamin B3. The body turns it into NMN and then into NAD+. It is sold as a supplement.
- Niacin and nicotinamide are the everyday forms of vitamin B3 in food and multivitamins. They are also turned into NAD+.
This matters because almost all the human research is on NMN and NR swallowed as supplements. Very little is on NAD+ itself. So evidence about NMN or NR cannot tell you whether an NAD+ drip or injection works. They are different products, taken in different ways.
What does the research actually show?
It helps to separate the evidence into five levels. Each level is harder to reach than the one before, and the marketing often skips straight from the first to the last.
1. The biology is real
Nobody disputes that NAD+ is essential. Without it, cells cannot produce energy or repair DNA. That is why it is such an attractive target for research.
2. Animal studies are promising, but mixed on lifespan
In a 2016 study, giving NMN to mice for a year reduced several signs of age-related decline. A separate 2016 study reported that NR increased lifespan in mice.
But other results were less encouraging. Vitamin B3 in the form of nicotinamide improved aspects of health but not lifespan in mice. The US National Institute on Aging’s Interventions Testing Program, which tests anti-ageing compounds in genetically varied mice, found that NR did not extend lifespan in either males or females.
Results in mice also often fail to carry over to people.
3. NMN and NR raise NAD+ levels in human blood
This is the most consistent human finding. In a 2018 trial in healthy middle-aged and older adults, NR raised NAD+ levels in blood cells and was well tolerated. A 2023 trial in 80 healthy middle-aged adults found that NMN raised blood NAD levels.
A 2026 systematic review of 33 human studies found that NMN and NR consistently raised NAD-related markers in blood. (A systematic review pulls together all the relevant studies on a question.)
But blood is not the same as the inside of your muscles, brain or skin. In a 2019 trial in older men, NR raised NAD-related markers in muscle but did not change how well the muscle’s mitochondria produced energy.
4. Clinical benefits in humans are mixed and mostly small
Raising a marker in the blood is not the same as making people healthier. When trials look at real health measures, the results are patchy:
- In a 2021 trial in 25 women with prediabetes, NMN improved how well their muscles responded to insulin. This was a small, short trial in one specific group.
- In a 2018 trial in 40 men with obesity, NR did not improve insulin sensitivity.
- A 2024 analysis of 19 trials found reductions in total cholesterol and triglycerides but no effect on other measures of metabolic health, and rated the evidence low to very low quality.
- A 2025 analysis found that NMN did not improve muscle mass, grip strength or walking speed in older adults.
- A 2026 analysis of NMN trials found no clear effect on weight, blood sugar or cholesterol, apart from a slight fall in one blood pressure reading.
The 2026 systematic review summed it up: effects on health outcomes were varied and often absent, and whether NAD+ boosting works for anti-ageing or wellness remains inconclusive.
5. There is no evidence that any of them extend human life
No study has shown that NAD+, NMN or NR helps people live longer. A trial able to show this would need to run for many years, and none has been done.
Some small trials report changes in “epigenetic clocks”, which are blood tests that estimate biological age. For example, a 2024 trial of NR reported a small change in these clocks. These tests are research tools. A change in one is not the same as ageing more slowly or living longer.
NAD+ injections and IV drips: what is actually known?
Clinics offer NAD+ as an IV drip, which can run for several hours, or as an injection under the skin or into a muscle. The key question is simple: does NAD+ put into the bloodstream get into your cells and do anything useful there?
The only published study we found that tracked what happens to infused NAD+ in people was a 2019 pilot study. It found that blood NAD+ levels did not rise for the first two hours of a six-hour drip. The researchers concluded it was being rapidly removed from the blood, and the breakdown products they measured suggested enzymes were breaking it down. Some was later passed out in urine.
That study did not measure whether NAD+ reached the inside of cells, and it did not look at any health outcome. The 2026 systematic review found no trials with health outcomes that tested NAD+ drips or injections for anti-ageing or wellness.
Research is only just starting. Trials registered on ClinicalTrials.gov include a study comparing how well injected NR and NAD+ are tolerated and a planned trial of an NAD+ injection for blood vessel ageing. The registry lists the first as still recruiting and the second as not yet recruiting, and neither has posted results.
For what NAD+ drips cost in the UK and what clinics offer, read our article on whether NAD+ IV drips are worth £550 a session.
What about NAD+ supplements you swallow?
Capsules containing NAD+ itself are widely sold. There is very little human research on them. Cells mainly make their NAD+ from smaller building blocks, as the 2021 review describes, which is why most scientists study NMN and NR instead. We found no good evidence that swallowing NAD+ raises NAD+ inside your cells.
Energy, exercise, brain and skin: do the claims stack up?
These are the benefits most often promised. Here is what the human studies of NMN and NR show. Remember, none of these tested NAD+ drips or injections.
- Energy and tiredness. In a 2022 trial in 108 older adults, NMN taken in the afternoon improved a leg-strength test and drowsiness scores, although drowsiness also improved in one of the placebo groups. A 2024 trial in 60 older adults found no difference on its main walking test, though walking speed and sleep scores were better on some other measures.
- Exercise. A 2021 trial in 48 amateur runners reported improved aerobic capacity with NMN over six weeks. It was small and short, and we found no larger trial confirming it.
- Metabolism and weight. As above, the large analyses show small or no effects.
- Brain. In a 2024 trial in 20 older adults with memory problems, NR more than doubled blood NAD+ but did not change memory and thinking scores. In a small 2022 trial in 30 people with Parkinson’s disease, NR was well tolerated and raised NAD levels in the brain, with mild improvement in some patients. Larger trials are needed.
- Skin. We found no good-quality human trials showing that NAD+ drips, injections or supplements improve skin ageing. If skin is your interest, our GHK-Cu guide covers another popular anti-ageing ingredient.
- Longevity. There is no human evidence, as explained above.
Is NAD+ safe?
For NMN and NR taken by mouth, trials lasting weeks to months have generally found them well tolerated. A 2026 analysis of NMN trials found no increase in side effects or liver problems, and a 2019 trial of NR found no difference in side effects compared with placebo.
Long-term safety over years is not known. The 2021 review lists whether restoring NAD+ in older people is safe as one of the big open questions.
For NAD+ drips and injections, safety has not been established in proper trials. Any treatment given through a drip or needle also carries its own risks, such as infection or irritation where the needle goes in.
NR is a form of vitamin B3 and NMN is closely related. The NHS warns that high doses of a different form of B3, nicotinic acid, can cause skin flushing and, over time, liver damage. The 2019 NR trial reported no flushing, but the long-term effects of high doses of any of these compounds are not well studied. If you are pregnant or breastfeeding, have a long-term condition or take any medicines, speak to your GP or pharmacist before taking any NAD+ product.
Is NAD+ treatment legal and approved in the UK?
The answer depends on the product.
- Drips and injections. We could find no NAD+ product on the MHRA’s database of licensed medicines (MHRA products database, checked September 2026). As far as we can tell, no NAD+ drip or injection holds a UK licence for anti-ageing, energy, longevity or any other use. Unlicensed does not automatically mean illegal: UK prescribers can order unlicensed medicines, known as “specials”, for individual patients, as MHRA guidance explains. But it does mean no UK regulator has assessed these products’ quality, safety or effectiveness for these uses. A product presented as treating or preventing disease is regulated as a medicine, as the MHRA explains.
- Advertising. The Advertising Standards Authority has warned that health claims for IV drips need proper evidence and that prescription-only injections cannot be advertised to the public. In a February 2026 ruling, it found that anti-ageing claims for NAD+ patches, which contained NMN, had not been substantiated and were misleading.
- NR supplements. NR (as nicotinamide riboside chloride) is authorised by the Food Standards Agency as a novel food for use in food supplements in Great Britain.
- NMN supplements. NMN has not been authorised as a novel food in Great Britain, and an application to the Food Standards Agency is still being assessed. The FSA says that regulated products, which include novel foods, require authorisation before they can be sold in Great Britain.
- The NHS. We could find no NHS service or NICE guidance that offers or recommends NAD+ therapy for ageing, energy or longevity (searched September 2026).
The bottom line
NAD+ is one of the most important molecules in the body, and research into it is serious science. Levels probably fall in some tissues with age, and NMN and NR can raise NAD+ markers in human blood.
But that is where the solid evidence stops. Health benefits in human trials have been small, inconsistent or absent. We found no trials showing that NAD+ drips or injections improve ageing, energy or wellness, and no evidence that any NAD+ product helps people live longer. The gap between the biology and the sales pitch is large.
For more background, read our guide to peptides in the UK, our look at SS-31 and MOTS-c, two other compounds marketed for mitochondria and ageing, and our article on NAD+ IV drips in the UK.
Frequently asked questions
What is NAD+ in simple terms?
NAD+ is a helper molecule found in every cell. Your cells need it to turn food into energy and to repair DNA. Your body makes it, largely from vitamin B3 in your diet.
Does NAD+ decline with age?
Studies suggest NAD+ falls in some tissues as people get older, including the brain and blood. But human data are limited, and scientists do not yet know how much of a fall actually matters for health.
Are NMN and NR the same as NAD+?
No. NMN and NR are building blocks that the body turns into NAD+. Most human research is on NMN and NR taken as supplements, so it does not show whether NAD+ drips or injections work.
Do NAD+ injections or IV drips work?
There is no good evidence that they do. We found no published trials showing that NAD+ drips or injections improve ageing, energy or wellness. A small pilot study found that infused NAD+ was rapidly removed from the blood.
Can NAD+ slow ageing or help you live longer?
This has not been shown in people. Some mouse studies were promising, but a major US testing programme found that NR did not extend lifespan in mice. No human study has shown that NAD+, NMN or NR extends life.
Does NAD+ give you more energy?
NAD+ is essential for making energy inside cells, but that does not mean extra NAD+ makes you feel more energetic. Small trials of NMN on tiredness have shown mixed results, and we found no trials of NAD+ drips or injections for energy.
Is NAD+ safe?
NMN and NR supplements have been well tolerated in short trials. Long-term safety is unknown. The safety of NAD+ drips and injections has not been established in proper trials.
Is NAD+ treatment approved in the UK?
We could find no NAD+ product licensed as a medicine in the UK. NR is authorised as a novel food for use in supplements, but NMN has not been authorised as a novel food in Great Britain.
Is NAD+ a peptide?
No. Peptides are short chains of amino acids. NAD+ is a different kind of molecule made from vitamin B3, even though it is often sold alongside peptides.
About this page
Page reviewed 30 September 2026. Sources checked include systematic reviews and meta-analyses in Ageing Research Reviews (2026), Nutrients (2026), the Journal of Cachexia, Sarcopenia and Muscle (2025) and Hormone and Metabolic Research (2024), human trials of NMN and NR, the 2019 intravenous NAD+ pilot study, the US Interventions Testing Program, ClinicalTrials.gov records, the MHRA products database and borderline products guidance, Food Standards Agency novel food records, Advertising Standards Authority guidance and rulings, NHS guidance on vitamin B3 and a search of NICE guidance. This guide is for information purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting, stopping or changing treatment.
Key facts at a glance
- NAD+ is a helper molecule found in every cell. It is essential for turning food into energy and for repairing DNA.
- It is made in the body, largely from vitamin B3 in food. It is not a peptide.
- NMN and NR are building blocks that the body turns into NAD+. They are not the same thing as NAD+.
- Human trials show NMN and NR can raise NAD+ levels in blood. Clear health benefits have not been shown consistently.
- We found no published trials showing that NAD+ drips or injections improve ageing, energy or wellness.
- No study has shown that NAD+, NMN or NR helps people live longer.
- We could find no NAD+ product licensed as a medicine in the UK. NMN has not been authorised as a novel food in Great Britain.
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