If you've been researching NAD+ supplements, you've probably seen two acronyms come up over and over: NMN and NR. Both are sold as ways to raise NAD+ levels in your body. Both have published human research behind them. Both have ardent supporters and outspoken critics.
This guide explains what each one actually is, what the human evidence shows for each, and how to decide which is right for you. We'll be upfront — Ivvion makes NMN, not NR. We'll explain why we made that choice. You can take it or leave it.
A 60-second primer on NAD+
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell of your body. It powers cellular energy production and activates the enzymes responsible for DNA repair and cellular maintenance. The amount of NAD+ in your tissues declines steadily from young adulthood onward; by age 50 it's roughly half of what it was at 25.
You can't take NAD+ directly — the molecule is too large to absorb through the gut intact. So supplement researchers have focused on precursors: molecules your body can convert into NAD+.
The two leading precursors on the market are NMN and NR. Both work. The differences are technical, and worth understanding before you spend money on either.
What is NR?
NR stands for nicotinamide riboside. It's a form of vitamin B3 that the body converts into NAD+ through a multi-step pathway: NR → NMN → NAD+.
NR was the first NAD+ precursor to reach the consumer supplement market in a serious way, starting around 2013 when ChromaDex licensed it under the brand name Niagen. Most premium NR supplements use Niagen as their raw material.
The case for NR rests on three things. First, NR has been on the market longer than NMN, which means more cumulative human safety data. Second, NR is smaller than NMN, which some researchers have argued makes it easier to absorb. Third, NR has been through multiple peer-reviewed human trials demonstrating that it raises NAD+ in blood.
The case against NR rests on one thing. NR has to be converted into NMN before it becomes NAD+. So if your body's conversion machinery for that step is slow or impaired (which it can be in older adults), you may be getting less of the active molecule than you think.
What is NMN?
NMN stands for nicotinamide mononucleotide. It's one biochemical step closer to NAD+ in the conversion pathway: NMN → NAD+ directly.
NMN reached the consumer market later than NR, gaining real traction around 2018–2020. The most well-studied branded form of NMN is Uthever®, manufactured under pharmaceutical-grade conditions and used in most of the human clinical trials referenced below.
The case for NMN rests on three things. First, it's the direct precursor to NAD+, skipping a conversion step. Second, the most recent and physiologically meaningful human trials (improvements in insulin sensitivity, walking speed, aerobic capacity) have been on NMN, not NR. Third, the absorption story has been resolved by newer delivery technology — sublingual and liposomal NMN formulations get the molecule into the bloodstream effectively.
What the human studies actually show
NR — the major human trials:
Martens et al, 2018, Nature Communications. University of Colorado Boulder. 24 healthy adults aged 55–79 given 1,000 mg/day of NR for 6 weeks. NR group showed increased NAD+ in blood and reduced systolic blood pressure. Small trial, modest effects.
Conze et al, 2019, Scientific Reports. 140 healthy overweight adults given 100–1,000 mg of NR for 8 weeks. NR raised NAD+ levels dose-dependently. No clinically meaningful changes in metabolic markers.
Remie et al, 2020, American Journal of Clinical Nutrition. Maastricht University. 13 overweight insulin-resistant men given 1,000 mg of NR for 6 weeks. NR raised NAD+ but did not improve insulin sensitivity or other metabolic markers.
NMN — the major human trials:
Yoshino et al, 2021, Science. Washington University in St Louis. 25 postmenopausal prediabetic women given 250 mg of NMN per day for 10 weeks. Roughly 25% improvement in muscle insulin sensitivity versus placebo.
Igarashi et al, 2022, npj Aging. Keio University, Japan. 108 healthy older adults given 250 mg of NMN daily for 12 weeks. Improvements in walking speed and grip strength.
Liao et al, 2023, Journal of the International Society of Sports Nutrition. Recreational runners given 300 mg of NMN daily for 6 weeks. Improvements in aerobic capacity.
Honest caveats
These are still small trials. None of them is a 10,000-person mega-study. The effect sizes are modest. The long-term effects of multi-year supplementation are still being studied. Direct head-to-head trials of NMN vs NR are vanishingly rare.
How to choose between NMN and NR
Pick NR if: you want the option with the longest cumulative human safety record. You've taken NR before and felt good results.
Pick NMN if: you want the precursor with the strongest recent human-trial evidence on downstream physical outcomes. You can afford to choose a premium liposomal delivery system if absorption is a concern.
Pick neither (yet) if: you're under 35 and healthy. Food, sleep, exercise, and not being chronically over-stressed do more for your NAD+ than any pill.
Why Ivvion makes NMN and not NR
We chose NMN for three reasons. First, the recent human evidence on NMN is the strongest in the category. Second, the delivery technology problem has been largely solved by liposomal formulations. Third, the Uthever® supply chain is well-established and pharmaceutical-grade.
If you've decided NMN is for you: Ivvion NMN Essential — clinical-trial-dose NMN using Uthever® raw material. Ivvion NMN Elite — higher-strength NMN with LipoAvail™ liposomal delivery. Both backed by a 30-day money-back guarantee. £10 off your first bottle with code WELCOME10.
Food supplement. Not a medicine. Does not diagnose, treat, cure or prevent any disease. Consult a healthcare professional if you are pregnant, breastfeeding, on medication, or have a medical condition. Last updated: 21 May 2026.