NAD⁺, Cellular Energy and Age: Why Nicotinamide Riboside Becomes More Relevant as We Age
NAD⁺ is an essential molecule for energy production and numerous repair processes in our cells. Its availability may decline with age, and nicotinamide riboside is being intensively studied as a potential precursor.
Summary
NAD⁺—short for nicotinamide adenine dinucleotide—is involved in numerous metabolic processes. This coenzyme is particularly important for mitochondrial energy production and for enzymes involved in cellular repair and stress responses.
Research suggests that NAD⁺ availability may decline over the course of a lifetime. However, the extent of this decline varies depending on the tissue, health status and measurement method.
Nicotinamide riboside, or NR, is a form of vitamin B3 and a precursor of NAD⁺. Human studies show that NR supplementation can influence NAD⁺ metabolism and increase certain NAD⁺ metabolites. Whether this produces long-term health benefits in healthy people has not yet been conclusively established.
What NAD⁺ Does in the Body
NAD⁺ is a coenzyme—a helper molecule without which important metabolic processes could not take place.
It switches between two forms: NAD⁺ and NADH. This enables it to accept and transfer electrons. The process is essential for converting nutrients into usable cellular energy.
Cellular Energy Production
NAD⁺ is involved in reactions through which mitochondria obtain energy from carbohydrates, fats and proteins. This energy is primarily provided in the form of ATP.
DNA Repair
Certain enzymes, including PARPs, require NAD⁺ to help detect and repair DNA damage.
Cellular Stress Responses
Sirtuins also require NAD⁺. These enzymes are studied in relation to metabolic regulation, stress responses and healthy ageing, among other areas.
NAD⁺ therefore performs two key functions: it supports both energy production and processes involved in cellular maintenance and adaptation.
Why NAD⁺ Metabolism Changes with Age
Preclinical research and some human studies suggest that NAD⁺ availability in certain tissues may decline over the course of a lifetime.
Several processes are being discussed as possible causes:
- Changes in the activity of enzymes that produce and recycle NAD⁺
- Higher NAD⁺ consumption through DNA repair and stress-response processes
- Chronic, low-grade inflammation
- Changes in mitochondrial metabolism
- Age-related changes in different tissues and organs
A decline of up to 50 percent between young and later adulthood is often cited. However, such a general figure cannot be applied to every person or tissue. The precise pattern has not yet been fully established scientifically.
Why Diet Alone Provides Only Limited NAD⁺
NAD⁺ itself is not absorbed directly from food in relevant quantities. Instead, the body produces it from various precursors.
These include the amino acid tryptophan and different forms of vitamin B3, such as nicotinic acid, nicotinamide and nicotinamide riboside.
Nicotinamide riboside also occurs in certain foods, but usually only in small amounts. Targeted supplementation therefore provides much more clearly defined quantities than are normally consumed through diet.
This does not automatically mean that everyone needs additional NR. Whether supplementation is appropriate depends on factors including diet, age, health status and individual goals.
Nicotinamide Riboside as an NAD⁺ Precursor
After absorption, nicotinamide riboside is converted into NAD⁺ through several enzymatic steps. The NRK pathway plays an important role in this process.
In Simplified Terms
- Nicotinamide riboside is taken up by the cell.
- NR is converted into nicotinamide mononucleotide, or NMN.
- The cell can then use NMN to produce NAD⁺.
Controlled human studies show that orally administered NR is bioavailable and can influence NAD⁺ metabolism. However, results regarding specific functional or clinical benefits have been mixed so far.
What Current Research Shows
NAD⁺ research has attracted considerable attention in recent years. However, many of the fundamental findings come from cellular and animal models. Robust long-term studies in healthy humans remain limited.
The NADage Study
The NADage study, conducted at the University of Bergen, is investigating NR in age-related frailty. This randomised phase II trial aims to determine whether longer-term supplementation can influence the intrinsic capacity of older adults.
As this is an ongoing clinical trial, no definitive conclusions can yet be drawn.
Werner Syndrome
A randomised crossover study published in Aging Cell in 2025 investigated NR in people with Werner syndrome—a rare inherited condition characterised by features of accelerated ageing.
The study reported good tolerability and changes in some of the markers examined. However, because of the rare condition and the small, highly specific group of participants, the results cannot be directly applied to healthy people.
Long COVID
A randomised study published in eClinicalMedicine in 2025 investigated NR in people with Long COVID.
NR increased measured NAD⁺ levels. However, the primary cognitive comparisons between NR and placebo showed no clear benefit. Some secondary and exploratory findings provided signals that need to be investigated further in larger studies.
Overall, the human studies available so far consistently show that NR can influence NAD⁺ metabolism. What remains unclear is the extent to which this produces noticeable or long-term health benefits in healthy people.
Who Might Find the NAD⁺ Pathway Interesting?
NAD⁺ metabolism is of particular interest to people focused on cellular energy, recovery and healthy ageing.
However, fatigue, longer recovery times or difficulty concentrating can have many different causes. They are not reliable indicators of low NAD⁺ levels and should be medically assessed if they persist.
Nicotinamide riboside should therefore not be regarded as a treatment for specific symptoms or conditions, but as the subject of a growing field of research.
What Nicotinamide Riboside Cannot Replace
Adequate Sleep
Regular, restorative sleep supports numerous repair and regulatory processes in the body.
Regular Exercise
Endurance and strength training support energy metabolism, mitochondrial function and overall physical performance.
A Balanced Diet
A varied diet provides the energy, proteins, vitamins and minerals the body needs for its daily functions.
Healthy Stress Management
Chronic stress can affect sleep, recovery and metabolism. Relaxation and intentional periods of recovery therefore remain essential.
Safety Information
- Nicotinamide riboside was generally well tolerated at the doses investigated in clinical studies.
- The product’s recommended daily intake should not be exceeded.
- Medical advice should be sought before use during pregnancy or while breastfeeding.
- People with existing medical conditions or those taking medication should consult a doctor before use.
- Persistent fatigue, concentration problems or a noticeable decline in performance should be medically assessed.
Conclusion
NAD⁺ is a central molecule in energy metabolism and is involved in numerous cellular repair and regulatory processes.
Nicotinamide riboside can serve as a precursor that the body uses to produce NAD⁺. Human studies confirm that NR supplementation can influence NAD⁺ metabolism. The potential long-term benefits for healthy people require further investigation.
Sleep, exercise, a balanced diet and healthy stress management remain the foundation. Supplementation may complement these factors, but it cannot replace them.
Nicotinamide Riboside in Unlock Tomorrow
Unlock Tomorrow combines nicotinamide riboside with six other carefully selected nutrients that support different areas of energy metabolism and normal bodily functions.
Unlock Tomorrow – An Overview of the FormulaNote: Replace href="#" with the URL of the overview article.
Sources
- NADage Study: Nicotinamide Riboside Replenishment in Aging-Related Frailty, ClinicalTrials.gov
- Shoji et al.: Nicotinamide Riboside Supplementation Benefits in Patients With Werner Syndrome, Aging Cell, 2025
- Wu et al.: Effects of Nicotinamide Riboside on NAD⁺ Levels, Cognition, and Symptom Recovery in Long COVID, eClinicalMedicine, 2025
Food supplements should not be used as a substitute for a balanced and varied diet and a healthy lifestyle. The recommended daily intake should not be exceeded. Keep out of reach of young children.
This article is intended for informational purposes only and does not constitute medical advice. If you have any health concerns, please consult a qualified medical professional.
