Healthy aging supplements: overview and selection guide

Healthy aging supplements, often also called longevity supplements, are researched in relation to cellular energy, repair processes, antioxidant balance, and metabolism. They cannot stop or reverse aging and are not a substitute for a healthy diet, sufficient exercise, sleep, recovery, and appropriate medical care.

Aging is a normal and complex biological process. As we age, energy metabolism, muscle function, recovery capacity, and metabolic flexibility, among other things, can change. Researchers therefore study the potential role of specific nutrients and supplements within these processes. However, the amount and quality of evidence vary greatly by substance, dosage, study duration, target group, and measured outcome.

In this guide, you can compare frequently discussed substances such as NMN, GlyNAC, and TMG. You will read about the biological processes they are associated with, what human research does and does not yet show, why they are sometimes combined, and what to look for regarding quality, dosage, safety, and responsible use.

What are supplements for healthy aging?

Healthy aging supplements are dietary supplements being researched or used in relation to processes that may change during aging. Examples of such processes include energy metabolism, oxidative balance, methylation, muscle function, and cellular maintenance. The term longevity supplements is an informal collective name and not an officially established medical product category.

Not every supplement presented as a longevity supplement has the same effect or the same scientific foundation. Some substances are well-researched for a specific biochemical function, while there is much less evidence for noticeable health benefits or long-term effects.

It is therefore important to distinguish between a biological mechanism, a change in a biomarker, and a demonstrable health benefit. The fact that a substance is involved in a certain process does not automatically mean that extra intake improves that process in healthy people.

The World Health Organization describes healthy aging as developing and maintaining the functional ability that enables well-being in older age. Healthy aging thus goes much further than just supplement use.

Do you want to understand the underlying biological processes first? Then read our explanation of longevity at the cellular level and the practical guide on cellular energy, recovery, and balance.

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Why are healthy aging supplements being researched?

During aging, various biological processes can change. These changes do not occur in the same way for everyone and are influenced by genetic factors, diet, physical activity, sleep, stress, medical conditions, medication, and environmental factors.

Within research into healthy aging, the following are examined, among others:

  • the production and use of cellular energy;
  • the functioning of mitochondria;
  • the availability of NAD+;
  • oxidative and reductive processes;
  • the formation and recycling of glutathione;
  • methylation and homocysteine metabolism;
  • muscle function and physical resilience;
  • inflammation-related biomarkers;
  • metabolic flexibility;
  • cellular maintenance and repair processes.

These topics are scientifically interesting, but research into a biological process is not the same as proof that a supplement slows down aging. Many studies are small, last relatively short, or only measure biomarkers. Long-term research into relevant health outcomes in large groups of people is still limited for many longevity supplements.

The Netherlands Nutrition Centre provides general information about dietary supplements and emphasizes that for most people, supplements are not a substitute for a healthy and varied diet.

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Comparing NMN, GlyNAC, and TMG

NMN, GlyNAC, and TMG are different substances with different biological functions. They can therefore not be considered interchangeable supplements.

Comparison of frequently discussed healthy aging supplements
Supplement What is it? Key research area What do we know? What do we not yet know?
NMN Nicotinamide mononucleotide, an intermediate in the formation of NAD+. NAD+, energy metabolism, and age-related biomarkers. Small studies show that intake can increase measured NAD+ levels in the blood. The clinical significance, optimal dosage, and long-term effects are not yet sufficiently clear.
GlyNAC A combination of glycine and N-acetylcysteine. Glutathione, redox processes, and some functional outcomes. Small studies in older adults report changes in various biomarkers and functional measurements. Larger, independent, and longer-term studies are needed to confirm the results.
TMG Trimethylglycine, also known as betaine. Methyl group transfer and homocysteine metabolism. The biochemical function of betaine as a methyl group donor is well-described. Specific evidence for healthy aging, slowing of aging, or life extension is limited.

The table shows that these substances are viewed from different research areas. A change in NAD+, glutathione, or homocysteine does not automatically mean that someone feels better or ages demonstrably healthier.

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NMN and NAD+

NMN stands for nicotinamide mononucleotide. It is a substance that occurs in the body as an intermediate step in the formation of NAD+. NAD+ is a coenzyme involved in various cellular reactions, including reactions in energy metabolism.

NMN is researched because NAD+-related processes can change during aging. In several human studies, an increase in the measured NAD+ level in the blood was observed after NMN intake. However, an increase in this biomarker does not prove that NMN slows aging, prevents diseases, or extends human lifespan.

A randomized, double-blind, and placebo-controlled study investigated daily NMN intake in healthy older men. The researchers reported an increase in NAD+ levels in the blood, but not all investigated functional outcomes changed clearly.

View the original human NMN study in npj Aging.

Read more within Every Day Better about:

Important when evaluating NMN research

  • Check how many participants took part in the study.
  • Look at how long the research lasted.
  • Note the daily amount used.
  • Check whether a biomarker or a noticeable health outcome was measured.
  • See if the research has been independently repeated.
  • Do not automatically adopt research dosages as personal usage advice.

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GlyNAC and glutathione

GlyNAC is a combination of glycine and N-acetylcysteine, usually abbreviated as NAC. Glycine and cysteine are involved in the formation of glutathione. Glutathione is an endogenous substance that plays a role in redox processes and various enzymatic reactions.

GlyNAC is researched because the availability of glycine, cysteine, and glutathione can vary among some groups. Small human studies in older adults reported changes in various biomarkers and some functional outcomes. However, these studies were limited in size and duration.

A randomized study divided 24 older adults into a GlyNAC group and a placebo group. The intervention lasted sixteen weeks. Because each group consisted of only twelve older participants, the results cannot simply be translated to all adults.

View the placebo-controlled GlyNAC study in The Journals of Gerontology.

Infographic about how GlyNAC works that shows how GlyNAC works: glycine and NAC support the production of glutathione and antioxidants as we age.

Infographic showing how GlyNAC works: glycine and NAC support the production of glutathione and antioxidants during aging.

GlyNAC combines glycine and NAC, two substances involved in the formation of glutathione.

It is more accurate to say that glycine and NAC are involved in the formation of glutathione than to claim that GlyNAC causes proven protection, detoxification, or cellular repair. Such broader health outcomes have not been conclusively demonstrated.

Read more within Every Day Better about:

For the exact ingredients and amount per capsule, view the product information for the GlyNAC capsules 60 × 600 mg.

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TMG, betaine, and methylation

TMG stands for trimethylglycine and is a form of betaine. TMG can function as a methyl group donor in the body. Via the enzyme betaine-homocysteine methyltransferase, betaine is involved in the conversion of homocysteine to methionine.

Methylation is a collective term for biochemical reactions in which a methyl group is transferred between molecules. These reactions are involved in various metabolic processes. This does not mean that more methylation is automatically better or that everyone needs extra methyl group donors.

TMG is researched in relation to, among others:

  • homocysteine metabolism;
  • the conversion of homocysteine to methionine;
  • methyl group transfer;
  • specific metabolic biomarkers;
  • sports and performance-related outcomes.

The biochemical function of betaine is well-described, but specific evidence that TMG slows aging or extends lifespan is lacking. It is therefore better to describe TMG based on its concrete role in methyl group transfer and homocysteine metabolism.

Infographic about TMG, betaine, methyl group transfer, and homocysteine
TMG is a methyl group donor involved in homocysteine metabolism.

For betaine, there is a European health claim regarding normal homocysteine metabolism. Such a claim may only be used when the product and the recommended daily amount meet the official conditions. To check this, consult the EU Register of Nutrition and Health Claims.

Read more within Every Day Better about:

For the exact ingredients and amount per capsule, view the product information for the TMG capsules 60 × 500 mg.

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Can you combine NMN, GlyNAC, and TMG?

NMN, GlyNAC, and TMG have different biological backgrounds, but that does not prove that a combination is extra effective. The individual human studies on these substances usually did not study them as a single combined supplement routine.

The term synergy stack suggests that an enhancing or synergistic effect has been demonstrated. Without direct comparative studies, terms like combination, routine, or stack are more accurate.

Why are these substances combined anyway?

The combination is mainly based on theoretically different research areas:

  • NMN is discussed in relation to NAD+ and energy metabolism.
  • GlyNAC is discussed in relation to glycine, NAC, glutathione, and redox processes.
  • TMG is discussed in relation to methyl group transfer and homocysteine.

The fact that these research areas differ from each other does not mean that everyone needs all three supplements. Using more supplements is not automatically better.

Points of attention when combining

  1. Determine what concrete goal you want to achieve with a supplement.
  2. Check if multiple products contain the same ingredients or related substances.
  3. Preferably do not add multiple new supplements at the same time.
  4. Follow the recommended amount on the label.
  5. Do not automatically adopt dosages from scientific studies.
  6. Discuss combining supplements with a doctor or pharmacist if using medication or having medical conditions.

For a practical explanation of the different processes, read our guide on cellular energy, recovery, methylation, and hydration.

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Healthy aging per life stage

Age alone is no reason to use NMN, GlyNAC, TMG, or any other longevity supplement. Health status, diet, lifestyle, medication, medical history, and any demonstrated deficiencies are usually more relevant than a fixed age limit.

Younger adults

For younger and healthy adults, sleep, complete nutrition, exercise, sufficient recovery, and stress management remain the most important principles. A supplement without a clear goal may be unnecessary.

Middle age

Changes in energy, recovery, or resilience can have many different causes. It is wise not to automatically attribute persistent complaints to aging, mitochondria, or a lack of NAD+.

Older adults

At an older age, the chance of medication use, interactions, and changes in kidney or liver function increases. A simple routine with a clear reason for use is then preferable to combining many different supplements.

For some vitamins and minerals, there are specific age- or risk-related supplementation recommendations. These official recommendations are separate from commercial longevity routines. For this, view the current supplement advice from the Netherlands Nutrition Centre.

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How do you choose a supplement for healthy aging?

A good choice does not start with the most popular supplement, but with the question of what goal you have, what evidence exists for it, and whether the product is appropriate in your situation.

1. Check the exact substance

The label must clearly state which substance and which form the product contains. General terms such as longevity blend, anti-aging complex, or cellular support say little when the exact ingredients and amounts are not stated.

2. View the amount per recommended daily dose

Do not just look at the amount per capsule. Check how many capsules or scoops the manufacturer recommends as a daily amount and calculate the total daily intake.

3. Compare the product with the research

Check whether the scientific research investigated the same substance form, amount, duration of use, and target group. A study with animals, cells, or a very specific patient group cannot automatically be translated to healthy adults.

4. View which outcome was measured

A change in a biomarker is different from an improvement in health, functioning, or quality of life. Therefore, do not just look at the conclusion in a marketing text, but also at what researchers actually measured.

5. Check warnings and usage instructions

A transparent supplement states the ingredients, amount per daily dose, warnings, batch code, expiration date, and the responsible company.

6. Check the legal status and permitted claims

Scientific interest in a substance does not automatically mean it is permitted as a dietary supplement or that every health claim may be used. If in doubt, consult official information from the European Commission, EFSA, and the NVWA.

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Quality and laboratory testing

Laboratory tests can help to check the identity, content, and purity of a product. The value of a certificate of analysis depends on the parameters investigated, the test method used, the laboratory, and whether the certificate actually belongs to the batch being sold.

A useful certificate of analysis can contain information about:

  • the identity of the substance investigated;
  • the measured content;
  • microbiological quality;
  • heavy metals;
  • other possible contaminants;
  • batch number and test date;
  • the analysis method used;
  • the performing laboratory.

A COA or laboratory test does not prove that a supplement has a health benefit. The document only provides information about the product properties investigated.

See how Every Day Better makes certificates and laboratory information available.

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Safety and responsible use

The fact that a substance is natural, endogenous, or scientifically researched does not automatically mean that extra intake is safe or necessary for everyone. Side effects, interactions, incorrect dosages, and quality differences remain possible.

Before use, ask for advice from a doctor, pharmacist, or other qualified healthcare professional in case of:

  • pregnancy or breastfeeding;
  • use by children or young people;
  • medication use;
  • a chronic or acute medical condition;
  • a kidney or liver disease;
  • a planned surgery or medical treatment;
  • unexplained or persistent physical complaints;
  • the simultaneous use of multiple supplements.

Follow the recommended amount on the product label. Stop use in case of unexpected complaints and discuss these with a healthcare professional if necessary.

In addition, read the information from the NVWA on dietary supplements and the points of attention from the Netherlands Nutrition Centre.

The information on this page is intended solely for general and educational purposes. The content is not a diagnosis, treatment, or personal medical advice.

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Every Day Better product information

Do you want to view the ingredients, composition, usage information, and amount per capsule or serving? Then use the product pages below. The product pages are intended for concrete product information and are separate from the general explanation and comparison in this guide.

NMN product information

GlyNAC product information

TMG product information

Hydration and electrolytes

ORS is primarily a product for fluid and electrolyte balance and is therefore not positioned in the same way as NMN, GlyNAC, or TMG.

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Frequently asked questions about supplements for healthy aging

What are supplements for healthy aging?

Healthy aging supplements are dietary supplements being researched or used in relation to processes that may change during aging. Examples include NMN, GlyNAC, and TMG. The term longevity supplements is an informal collective name and not a medical product category.

Are longevity supplements the same as anti-aging agents?

No. Supplements cannot stop or reverse aging. The term longevity is used for research and strategies regarding healthy functioning during aging, but should not be interpreted as a guarantee of life extension.

Which supplements are often mentioned in connection with healthy aging?

NMN, GlyNAC, and TMG are frequently discussed. NMN is researched in relation to NAD+, GlyNAC in relation to glycine, NAC, and glutathione, and TMG in relation to methyl group transfer and homocysteine.

What is the difference between NMN, GlyNAC, and TMG?

NMN is an intermediate in the formation of NAD+. GlyNAC combines glycine and NAC, two substances involved in the formation of glutathione. TMG is a methyl group donor involved in homocysteine metabolism.

Which longevity supplement has the best evidence?

These substances cannot be fairly placed in a single ranking because studies measure different processes, target groups, and outcomes. For none of these substances has it been convincingly demonstrated that they slow down aging as a whole or extend human lifespan.

Can healthy aging supplements extend life?

There is no convincing evidence for this in humans. Available studies usually measure biomarkers, tolerability, or short-term functional outcomes rather than whether users actually live longer.

Can you use NMN, GlyNAC, and TMG at the same time?

These substances are researched from different biological perspectives, but there is insufficient direct research on using all three as a combined stack. A theoretical difference in function does not prove an additional health benefit.

What is a synergy stack?

A synergy stack is a marketing or usage term for a combination of supplements that theoretically complement each other. The term does not mean that a synergistic effect has been scientifically proven. Combination or supplement routine is therefore often a more accurate description.

At what age do longevity supplements become relevant?

There is no general age at which NMN, GlyNAC, or TMG becomes necessary. Health status, diet, medication, lifestyle, and any demonstrated deficiencies are more important than a fixed age limit.

How do you recognize a reliable supplement?

Look for a clear list of ingredients, the amount per recommended daily dose, usage instructions, warnings, batch information, traceable laboratory documentation, and a responsible company within the European Union.

Does a laboratory test prove that a supplement works?

No. A laboratory test can provide information about identity, content, or contaminants, but does not prove health effects or clinical benefit.

Are supplements for healthy aging safe?

That depends on the substance, amount, product quality, duration of use, combination, health status, and any medication. Being well-tolerated in a small study does not mean a supplement is safe for everyone.

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Further reading within Every Day Better

Overarching explanation

NMN

GlyNAC

TMG

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Scientific and official sources

The sources below provide further information on healthy aging, dietary supplements, NAD+, NMN, GlyNAC, and European regulations regarding health claims.

  1. World Health Organization. Healthy ageing and functional ability.
  2. Netherlands Nutrition Centre. Dietary supplements.
  3. National Institutes of Health, Office of Dietary Supplements. Dietary Supplement Fact Sheets.
  4. Igarashi M. et al. Chronic nicotinamide mononucleotide supplementation elevates blood NAD+ levels in healthy older men.
  5. Kumar P. et al. Supplementing Glycine and N-Acetylcysteine in Older Adults.
  6. European Commission. EU Register of Nutrition and Health Claims.
  7. European Commission. Novel food information and authorisation.
  8. Netherlands Food and Consumer Product Safety Authority. Nutrition claims and health claims.
  9. Netherlands Food and Consumer Product Safety Authority. Information on dietary supplements.

Last substantive check: July 10, 2026.