NAD+ Supplements: NMN vs NR vs NADH, Doses, and What the Human Trials Show

Search for NAD+ supplements and you meet a wall of confident answers. NMN is the one. NR is the one. Take it under the tongue, take a gram a day, stack it with something else. Almost all of that confidence comes from someone with a bottle to sell. This guide takes a different route. It starts with what NAD+ actually does, explains why the NMN vs NR argument is far narrower than the marketing suggests, reports which human trial endpoints moved and which did not, and finishes with a plain checklist for choosing a NAD+ supplement you can actually justify.

What NAD+ Actually Is

NAD+ stands for nicotinamide adenine dinucleotide. It is a coenzyme found in every living cell, and it has two jobs that matter for how your body makes energy.

First, NAD+ carries electrons in the reactions that turn food into ATP, the molecule cells use as fuel. Without it, cellular energy production slows down.

Second, NAD+ is consumed as fuel by two families of enzymes: sirtuins, which respond to cellular stress, and PARPs, which are involved in DNA repair. When those enzymes work, the NAD+ is used up rather than passed along.

That is why the body runs on a NAD+ balance. Cells build it from several starting materials, including niacinamide, niacin, and tryptophan, and they also recycle it through a salvage pathway. Everything in this article is about that balance.

NAD+ levels by age: what the measurement shows

One of the most direct human measurements we have comes from a 2012 study by Massudi and colleagues (R1). They measured NAD+ in human tissue from 49 people aged 15 to 77, plus newborns, and found a strong negative correlation between tissue NAD+ and age: r = -0.706 in males and r = -0.537 in females.

The same study found that PARP activity rose with age in men and moved inversely with tissue NAD+ (r = -0.639). More repair demand came with age, and less NAD+ was left over.

One caveat matters here. Those samples were pelvic skin, one tissue type, not blood or muscle, and the relationship is a correlation, not proof of cause. It tells us NAD+ declines with age in human tissue. It does not tell you how far your own levels have moved.

A biomarker changing in a predictable direction is a real finding. It is not the same thing as a change in how a person feels or functions, and that gap runs through everything below.

The NAD+ Precursors, Mapped

A NAD+ precursor is a compound the body can convert into NAD+. That is the whole category. The differences between the options come down to how many conversion steps sit between the capsule and the coenzyme, and how much human research exists for each one. If you would rather take the coenzyme itself than a precursor, a liposomal NAD+ liquid is the direct route.

NMN (nicotinamide mononucleotide)

NMN sits one structural step from NAD+. It carries the largest share of the marketing attention, and it is the form used in the 60-day trial in healthy middle-aged adults covered below. NMN is also sold on its own as a 500 mg capsule.

NR (nicotinamide riboside)

NR is a form of vitamin B3 found in small amounts in food, and it is among the best studied oral NAD+ precursors in humans. In mouse and cell models, NR raises NAD+ and activates SIRT1 and SIRT3 (R12). Those are animal and cell findings. They are mechanism work, not human outcomes, and they should always be read that way.

Niacinamide and niacin

Niacinamide and niacin sit earlier in the same pathway. They are inexpensive, widely available in general multivitamins, and used by the body for many jobs beyond NAD+ production.

NADH

NADH is the odd one out on this list. It is not a precursor in the usual sense. It is the reduced, electron-carrying form of NAD+ itself, and it gets its own section further down.

Where they overlap

Here is the part most guides leave out: at the pathway level, NMN and NR converge. The next section explains what that does to the way you should read the NMN vs NR comparison.

The Part Most Guides Skip: NMN Converts to NR First

In 2016, Ratajczak and colleagues mapped how cells actually take these compounds up (R3). They found that an enzyme called NRK1, or nicotinamide riboside kinase 1, is necessary and rate-limiting for a cell to use exogenous NR and NMN for NAD+ synthesis.

Using stable isotope labeling, they showed that NMN is metabolized outside the cell into NR. The NR is then taken up and converted into NAD+ inside the cell.

Both precursors funnel through the same rate-limiting step. That single fact explains why the two compounds keep producing such similar effects across study after study.

To be precise about the evidence: this is a mammalian cell and genetic model study. It is the mechanism that explains the overlap between NMN and NR, not a human outcome trial. Read it as mechanism, not as a result you can expect in your own body.

What this means when you are shopping

The NMN vs NR question is real, but narrower than the sales pages suggest. You are not choosing between a compound that works and one that does not. You are choosing between two compounds that reach NAD+ through a shared bottleneck.

Real differences still exist, and they are worth comparing. They show up in the dose each human trial used, the cost per gram, the stability of the raw material, and what a given manufacturer can document. The "only one of these works" framing is not one of those differences.

The practical takeaway: pick the form whose human trial record you can actually read, at a dose that trial used. That filter will beat the front of the bottle every time.

What the Human Trials Actually Found

The human data follow a consistent shape. NAD+ markers go up. Functional outcomes are mixed, and the honest papers say so in their own conclusions.

Here is the verified trial set behind this article: the form tested, who was studied, the dose and duration, and what moved and what did not.

A note on that dose column: we only print milligram figures that the trial reports. Where a verified summary does not state a dose, the table says so rather than filling the gap with a guess.

What rose consistently

Every human study above that measured blood or muscle NAD+ found it went up. Trammell 2016 (R2) tested single oral NR doses of 100, 300, and 1,000 mg and saw a dose-dependent rise in the blood NAD+ metabolome.

One number from that paper gets repeated everywhere: a 2.7-fold rise in blood NAD+. It came from a pilot of one person. Treat it as a signal that the pathway responds, not as a result you should expect.

Martens 2018 (R4) found chronic NR well tolerated and effective at stimulating NAD+ metabolism in healthy middle-aged and older adults. Yi 2023 (R6) found blood NAD+ rose significantly across the graded NMN groups. Igarashi 2022 (R7) found that daily NMN safely raised blood NAD+ over 12 weeks. A 2023 review (R9) sums the pattern up: NAD+ precursors safely elevate NAD+ levels in humans.

What did not move, and why that matters

Then there are the endpoints that stayed flat. These are the ones the brand pages tend to skip.

• Muscle bioenergetics. Elhassan 2019 (R5) gave 12 older men 1 g of NR daily for 21 days. The muscle NAD+ metabolome rose, and gene expression in energy and mitochondrial pathways moved downward, yet mitochondrial bioenergetics did not change.
• Insulin-resistance markers. Yi 2023 (R6) saw NAD+ rise and walking endurance improve over 60 days in 80 healthy middle-aged adults. Markers of insulin resistance showed no notable change.
• Mobility. Igarashi 2022 (R7) reported improvements in physical mobility that were nominal, meaning small and not robust.
• Blood pressure and arterial stiffness. Martens 2018 (R4) did not report these as findings. The researchers flagged them as something future trials should assess.

Raising NAD+ is well replicated. Turning that rise into a measurable functional change is not. A study can succeed at the first and come up empty at the second, and the strongest papers report both halves.

The honest ceiling

Two current reviews say the quiet part out loud. Pandolfi 2026 (R10) notes that oral NR and NMN can increase circulating NAD+, while clinical benefits remain variable and context-dependent, and that intravenous NAD+ is less well characterized and lacks robust clinical validation.

The same review explains why more is not simply better. NAD+ responses are nonlinear, shaped by dose, age, metabolic state, and route, and constrained by feedback and saturation.

Chmielewski 2026 (R11) goes further. Across mitochondrial interventions, no approach has been shown to slow aging or extend lifespan in healthy humans, and a biomarker moving toward a younger reference value does not establish rejuvenation.

That is not a reason to ignore NAD+ supplements. It is a reason to buy one with realistic expectations: support for a pathway your cells already depend on, not a transformation. For the wider picture of what this category can and cannot do, our longevity supplements guide covers the rest of the field.

NADH Is Not the Same as NAD+

NAD+ and NADH are a redox pair. NAD+ is the oxidized form, and NADH is the reduced form that carries an electron. Cells convert between the two constantly, and both are essential to how energy moves through a cell.

That relationship is exactly why the naming gets confusing. "NAD" gets used as shorthand for NAD+, and a bottle labeled NADH is not the same product as one labeled NAD+, NMN, or NR.

NADH is a finished coenzyme rather than a precursor waiting to be converted, and it is a different molecule. A milligram of NADH is not a milligram of NMN, and the two are not interchangeable amounts even when the labels sit side by side on a shelf.

If you are considering NADH, hold it to the same standard you would apply to NR and NMN: a specific human trial, a stated dose, and a result you can look up. The verified trial set for this article covers NR and NMN, so that is the comparison we can report on with confidence.

None of that makes NADH a poor choice. It makes it a separate question, and it deserves its own evidence rather than being folded into a NAD+ article as a synonym.

What Else Moves NAD+

Supplements are one lever. The strongest human evidence in this whole area points somewhere else.

Chmielewski 2026 (R11) states that exercise provides the strongest human evidence for coordinated mitochondrial and functional adaptation. The same review describes the evidence for energy restriction, NAD+ precursors, mitophagy-supporting compounds, and mitochondria-targeted agents as heterogeneous and endpoint-specific.

If you want one intervention with a strong human record behind it, that intervention is training, not a capsule.

How to increase NAD+ levels with the things you already do

Popular protocols built on fasting, cold exposure, and light therapy get far more attention than measurement. Human NAD+ data for those approaches is thin, and the verified source set behind this article does not support a firm figure for any of them. Be skeptical of precise percentages attached to protocols nobody has measured in people.

What does follow from the mechanism is a strategy rather than a protocol: support the pathway from several directions at once. NAD+ production, mitochondrial efficiency, and the nutrients those systems depend on are related problems, which is why our guide to mitochondrial dysfunction and nutritional support treats them together. For the mitochondrial half of that strategy, an ATP-focused formula is a separate product category from a NAD+ precursor.

Keep moving, take a formula you can justify, and give it months rather than days. The Agape catalog is built around that layered approach rather than single-ingredient promises.

How to Choose an NAD+ Supplement

If you decide to buy, the label is where most of the value is won or lost. Here is a short checklist.

1. Pick a form with a readable trial record. NR and NMN both have human studies behind them, and both funnel through the same enzyme step. Choose the one whose trial you can actually open.
2. Match a dose that appears in a trial. The human studies above used single NR doses from 100 to 1,000 mg, 1 g of NR daily, and graded NMN up to 900 mg daily. A product that quietly underdoses the form it names gives you no way to compare your experience with any published result.
3. Check the delivery format against the ingredient. A capsule, a liposomal liquid, and an oral spray each present a compound differently. Ask what the format is for, and whether the label states how much active compound is in each serving.
4. Confirm third-party testing. Independent third-party testing is the difference between a label and a verified label.
5. Read the serving size, not the front of the bottle. Two products can both say NAD+ and differ by an order of magnitude in what one serving delivers.
6. Compare price per gram of the actual compound. Cost per bottle tells you nothing when bottle sizes and doses differ.

So what can the best NAD+ supplement realistically do? It can deliver a compound your cells already use, in a form and a dose that someone has studied. It cannot do the work that your training, sleep, and diet are doing.

That is the standard the Agape team applies when curating this category: a documented form, a documented dose, and documented testing. If you want to see how that plays out across a full range of mitochondrial formulas, the mitochondria collection is the place to start, and an ATP-focused companion is a separate category entirely, which the ATP Fuel and ATP 360 comparison explains.

One last note on scope. This article is about energy metabolism. If your interest is brain and memory support instead, the brain and memory hub is a better starting point, because that goal has its own evidence base and its own ingredients.

Four products carried by Agape cover the forms this article describes: a liposomal liquid, an NMN capsule, an oral spray, and a mitochondrial formula. Prices are current at the time of publication.

What We Recommend

References

1. Massudi H, Grant R, Braidy N, Guest J, Farnsworth B, Guillemin GJ. Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS One. 2012. DOI 10.1371/journal.pone.0042357. PMID 22848760
2. Trammell SA, Schmidt MS, Weidemann BJ, Redpath P, Jaksch F, Dellinger RW, Li Z, Abel ED, Migaud ME, Brenner C. Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nature Communications. 2016;7:12948. DOI 10.1038/ncomms12948. PMID 27721479
3. Ratajczak J, Joffraud M, Trammell SA, Ras R, Canela N, Boutant M, Kulkarni SS, Rodrigues M, Redpath P, Migaud ME, Auwerx J, Yanes O, Brenner C, Canto C. NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells. Nature Communications. 2016;7:13103. DOI 10.1038/ncomms13103. PMID 27725675
4. Martens CR, Denman BA, Mazzo MR, Armstrong ML, Reisdorph N, McQueen MB, Chonchol M, Seals DR. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications. 2018;9(1):1286. DOI 10.1038/s41467-018-03421-7. PMID 29599478
5. Elhassan YS, Kluckova K, Fletcher RS, Schmidt MS, Garten A, Doig CL, et al. Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome and induces transcriptomic and anti-inflammatory signatures. Cell Reports. 2019;28(7):1717-1728.e6. DOI 10.1016/j.celrep.2019.07.043. PMID 31412242
6. Yi L, et al. Chronic nicotinamide mononucleotide supplementation elevates blood NAD+ and improves walking endurance in healthy middle-aged adults. GeroScience. 2023. DOI 10.1007/s11357-022-00705-1. PMID 36482258
7. Igarashi M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. npj Aging. 2022. DOI 10.1038/s41514-022-00084-z. PMID 35927255
8. Irie J, et al. Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men. Endocrine Journal. 2020. DOI 10.1507/endocrj.ej19-0313. PMID 31685720
9. Song Q, et al. NAD+ metabolism and interventions: a review. Advances in Nutrition. 2023. DOI 10.1016/j.advnut.2023.08.008. PMID 37619764
10. Pandolfi S, Ghezzi C, Bjorklund G, Metalla M, Paone FM, Chirumbolo S. NAD+ biology and supplementation: from mechanisms to clinical perspectives. Molecular Biology Reports. 2026;53(1). DOI 10.1007/s11033-026-12351-3. PMID 42489969
11. Chmielewski PP. Mitochondrial homeodynamics in ageing: mechanisms, resilience, and interventions. Biogerontology. 2026;27(5). DOI 10.1007/s10522-026-10506-0. PMID 42720714
12. Canto C, Houtkooper RH, Pirinen E, Youn DY, Oosterveer MH, Cen Y, et al. The NAD+ precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet-induced obesity. Cell Metabolism. 2012;15(6):838-847. DOI 10.1016/j.cmet.2012.04.022. PMID 22682224

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