Quick answer: NAD+ is a molecule every cell needs for energy production and repair, and levels appear to fall in some tissues with age. Swallowed NAD+ is largely broken down in the gut, which is why many products use precursors such as nicotinamide riboside (NR) or nicotinamide mononucleotide (NMN), or a liposomal format. Human studies show precursors can raise blood NAD+ levels, but evidence for noticeable health benefits is still limited. Liposomal NAD+ is expensive and largely unproven.
What is NAD+?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in all living cells. It shuttles electrons in the reactions that turn food into energy and is used by enzymes involved in DNA repair and cell signalling, including sirtuins and PARPs. Your body makes NAD+ from vitamin B3 (niacin and nicotinamide) and from the amino acid tryptophan.
Why the interest?
Animal studies found that NAD+ levels decline with age and that boosting them improved several markers of metabolic health and ageing in mice. These findings drove a wave of supplements. Translating mouse results to people has proven much harder.
The forms on the market
| Form | What it is | Human evidence |
|---|---|---|
| Niacin / nicotinamide (vitamin B3) | Classic NAD+ building blocks | Long history; niacin causes flushing at high doses |
| Nicotinamide riboside (NR) | A B3 form converted to NAD+ | Several trials show increased blood NAD+; clinical effects modest or unclear |
| NMN | A direct precursor one step from NAD+ | Small trials show increased NAD+ and some metabolic signals |
| NAD+ (oral) | The molecule itself | Large molecule largely broken down during digestion |
| Liposomal NAD+ | NAD+ in phospholipid spheres | Very limited independent human data |
What human studies found
- NR raises NAD+: a 2016 study in Nature Communications (Trammell and colleagues) showed oral NR increased blood NAD+ in a healthy volunteer and in a dose-dependent way in follow-up work.
- NR in older adults: a 2018 trial (Martens and colleagues, Nature Communications) found 1,000 mg a day of NR for six weeks was well tolerated and raised NAD+ levels, with only tentative signs of effects on blood pressure and arterial stiffness.
- NMN in prediabetes: a 2021 study in Science (Yoshino and colleagues) found 250 mg a day of NMN for ten weeks improved muscle insulin sensitivity in a small group of overweight or obese postmenopausal women with prediabetes.
Overall, precursors raise NAD+ in blood. Whether that translates into more energy, slower ageing or disease prevention in humans has not been shown.
Is liposomal NAD+ worth it?
In theory, liposomes could protect NAD+ from breakdown in the gut (see Liposomal Absorption Explained). In practice, we found little independent, peer-reviewed human evidence that liposomal NAD+ raises tissue NAD+ more than NR or NMN, and premium liposomal NAD+ products can cost around $100 or more a month in Canada. If you want to try an NAD+ approach, discuss it with a health professional and consider products with published human data and an NPN.
Safety
- NR and NMN were generally well tolerated in short trials; reported side effects include nausea, bloating and headache.
- Long-term safety data are limited.
- NAD+ boosting influences cell growth pathways. People with cancer or a history of cancer should talk to their oncologist before using these products.
- High-dose niacin can cause flushing, liver problems and blood sugar changes; it should only be used under medical supervision.
Lifestyle factors that support NAD+
Regular exercise, adequate sleep, a diet with enough protein and B3 (poultry, fish, peanuts, whole grains, legumes) and limiting alcohol all support normal cellular energy metabolism, with far more evidence than any supplement.
Frequently asked questions
Is NMN or NR better?
Both raise NAD+ in small studies. There is no conclusive head-to-head evidence that one is clinically better.
Do NAD+ IV drips work?
IV NAD+ is offered by some clinics, but strong clinical evidence is lacking, and infusions can cause discomfort, nausea and flushing. It should only be given by a licensed professional.
Will NAD+ give me more energy?
Human trials have not shown consistent improvements in perceived energy or physical performance in healthy people.
Sources
- Trammell SAJ, et al. Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nature Communications, 2016.
- Martens CR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications, 2018.
- Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science, 2021.
- National Institutes of Health, Office of Dietary Supplements. Niacin fact sheet.
This article is for general information only and is not medical advice. See our medical disclaimer.
