You’re training consistently, sleeping reasonably well, eating quality food. But there are days where the output doesn’t match the effort. The engine feels like it’s running at 80%, and the usual explanations don’t quite cover it.
Most people put it down to stress, age, or the reality of a busy life. But there’s something else that happens inside every cell in your body, every day, that most people who train seriously have never looked at.
What Energy Actually Is, at the Cellular Level
The energy you do (or don't) feel starts with what your cells can produce. Before the espresso hits, before a training session gets you going, your body is running a continuous biochemical process inside trillions of cells: converting what you eat into a usable form of energy called ATP. Every heartbeat, every muscle contraction, every decision runs on it.
Two molecules sit at the heart of that process. NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell, involved in the transfer of electrons during energy metabolism. Think of it as part of the machinery that converts nutrients into fuel your cells can actually use. NAD+ is involved in hundreds of biochemical reactions in the body, acting as a coenzyme for the enzymes that drive energy metabolism and other core cellular processes.
CoQ10 (Coenzyme Q10) is a fat-soluble molecule found in the mitochondria, the structures responsible for producing the vast majority of your body’s energy. It acts as an electron carrier in the mitochondrial electron transport chain, enabling the final steps of ATP synthesis, and is naturally concentrated in the tissues with the highest energy demands: heart, skeletal muscle and brain.¹
They work on the same system from different angles, each contributing to a different part of the energy metabolism pathway.
The Research on NR and NAD+ in Humans
NAD+ is a large molecule that doesn’t cross cell membranes well when taken directly as a supplement. The research points instead to precursors, compounds the body can absorb and convert into NAD+ itself. Nicotinamide Riboside (NR) is one of the most studied.
Clinical studies have shown that nicotinamide riboside (NR) can increase NAD+ levels in humans.² ³ What is still being explored is how these changes relate to specific, measurable health outcomes in otherwise healthy adults.
CoQ10 and the Tissue It Protects
CoQ10’s role in cellular energy production is well established. Peer-reviewed research has documented that CoQ10 biosynthesis and tissue concentrations can decrease with age, with observed reductions particularly in heart and skeletal muscle.⁴ CoQ10 is one of several components involved in the mitochondrial electron transport chain, the process by which cells generate ATP.⁵
Reflex NAD+ includes 100mg of CoQ10 alongside the NAD+ precursor NR. These components are involved in different aspects of cellular metabolism, reflecting their distinct biochemical roles.
The Vitamins and Minerals That Complete the Formula
Reflex NAD+ is completed with a set of vitamins and minerals that carry authorised health claims on the GB Nutrition and Health Claims Register.⁶
Vitamin B12 contributes to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. Pantothenic acid (Vitamin B5) contributes to normal energy-yielding metabolism and to normal mental performance. Biotin contributes to normal macronutrient metabolism and to the maintenance of normal hair. Vitamins C and E contribute to the protection of cells from oxidative stress, and copper contributes to normal energy-yielding metabolism and the normal function of the immune system.
None of these are filler. Each is in the formula because of what the evidence supports, and because a formula designed for someone already running a considered supplement stack should be comprehensive rather than minimal.
Who This Is For
Reflex NAD+ is built for men in their late 30s to 50s who are already doing the right things — training regularly, eating well, running a considered stack — and want to support the cellular processes working behind the scenes. It’s not a quick fix. It’s for someone who understands that the body is a system and that supporting it at the cellular level is part of a longer strategy, not a shortcut.
One capsule daily, at whatever time suits you.
A Note on What the Science Does and Doesn’t Say
We’re a supplement brand that thinks honesty is part of the product. So here it is: the science on NAD+ supplementation in healthy adults is promising and growing, but it isn’t complete. Peer-reviewed human trials have indicated that NR can increase NAD+ levels. Whether those raised levels translate into specific, measurable health outcomes in people who are otherwise healthy is an area of active and ongoing research.
What the science does support, through authorised health claims and peer-reviewed evidence, is the role of the supporting ingredients in energy metabolism, mental performance and cellular protection. That’s the foundation this formula is built on.
The Bottom Line
Energy isn’t just about sleep, and it isn’t just about what you eat. It starts at the cellular level, with the processes that convert nutrients into something your body can actually use. Reflex NAD+ is built to support those processes: NR as a NAD+ precursor, CoQ10 involved in the mitochondrial electron transport chain and a set of vitamins and minerals with authorised health claims for energy metabolism, mental performance and cellular protection.
If you want to go deeper into the science, the research cited below is a good starting point.
And if you've made it this far, as you've probably guessed we will be launching our NAD+ product very soon, watch this space.
Frequently Asked Questions
What is NAD+ and why does it matter?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell. It plays a central role in energy metabolism, helping cells convert nutrients into usable energy and is involved in hundreds of metabolic reactions. It is one of the most studied molecules in cellular biology because of this central role. Because of this, it has become an area of significant interest in longevity and performance science.
Why take NR rather than NAD+ directly?
NAD+ is a large molecule that doesn’t cross cell membranes well when taken as a supplement, which limits its usefulness in that form. Nicotinamide Riboside (NR) is a precursor — a compound the body can absorb and convert into NAD+ itself. Clinical studies have shown that NR supplementation can increase NAD+ levels in humans.² ³
What does CoQ10 add to the formula?
CoQ10 works in the mitochondria, acting as an electron carrier that enables the final stages of ATP production. It’s naturally concentrated in tissues with high energy demands — heart, muscle and brain — and peer-reviewed research has documented that tissue levels can decrease with age.⁴ Including CoQ10 alongside NR means the formula contains ingredients that are each involved in different stages of the same metabolic pathway.
What do Vitamin B12 and Pantothenic Acid contribute?
Vitamin B12 contributes to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. Pantothenic acid (Vitamin B5) contributes to normal energy-yielding metabolism and to normal mental performance. Both are authorised claims on the GB Nutrition and Health Claims Register.⁶
Does NAD+ decline with age?
This is an area where the science is more nuanced than it’s often presented. A May 2026 study published in Nature Metabolism found that NAD+ levels in whole blood do not appear to change systematically with age in healthy adults, which challenges the widely repeated claim that decline is universal and inevitable. What the evidence does indicate is that NR supplementation raises NAD+ levels in humans, and that CoQ10 tissue concentrations can decrease with age. We’d rather tell you what the science actually says than repeat a simplified version of it.
Is Reflex NAD+ a medicine?
No. Reflex NAD+ is a food supplement. It is not intended to diagnose, treat, cure or prevent any disease or medical condition. If you have a health condition or are taking medication, consult your GP before use.
References
1. Crane, F.L. (2001). Biochemical Functions of Coenzyme Q10. Journal of the American College of Nutrition, 20(6):591–598. DOI: 10.1080/07315724.2001.10719063
2. Dellinger, R.W. et al. (2017). Repeat dose NRPT increases NAD+ levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study. npj Aging and Mechanisms of Disease. DOI: 10.1038/s41514-017-0016-9. PMC5701244.
3. Bagga, P. et al. (2024). Acute nicotinamide riboside supplementation increases human cerebral NAD+ levels in vivo. Magnetic Resonance in Medicine, 92(6):2284–2293. DOI: 10.1002/mrm.30227. PMC11436296.
4. Hernández-Camacho, J.D. et al. (2018). Coenzyme Q10 Supplementation in Aging and Disease. Frontiers in Physiology, 9:44. DOI: 10.3389/fphys.2018.00044. PMC5807419.
5. Hernandez-Camacho, J.D. et al. (2019). CoQ10 and Aging. Nutrients. PMID: 31083534. DOI: 10.3390/nu11051088.
6. UK Government. Great Britain Nutrition and Health Claims (NHC) Register. gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register
This article is for informational purposes only and does not constitute medical advice. Reflex NAD+ is a food supplement and is not intended to diagnose, treat, cure or prevent any disease. Food supplements should be used alongside a varied, balanced diet and healthy lifestyle, not as a substitute for either. If you are pregnant, breastfeeding, taking medication or have a medical condition, consult your GP before use. Keep out of reach of children.
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