longevity-glossary

Vitality Supplements · Reference

Longevity Glossary

Every key longevity and supplement term, defined in plain English. From NAD+ and NMN to sirtuins, autophagy, senolytics, berberine and GLP-1 — a clear, evidence-led reference from a UK supplement manufacturer.

Last updated June 2026 · Vitality Supplements Editorial Team · 40+ terms
Educational reference — food supplement information, not medical advice
UK manufactured ISO/IEC 17025 batch tested 40+ terms defined Evidence-referenced
In short
What is this glossary?
A plain-English reference to the longevity, NAD+ and supplement-science terms you'll meet across our guides — grouped into NAD+ and its precursors, the cellular mechanisms of ageing, metabolic terms, key actives, and supplement-quality concepts. Each definition is concise and links to a deeper guide where we have one. These are food supplements in the UK with no authorised health claims; this page is educational only.
Section 01

NAD+ & its precursors

The molecules at the centre of the cellular-energy and longevity conversation.

NAD+ Nicotinamide Adenine Dinucleotide
A coenzyme found in every living cell, essential for converting food into cellular energy and for DNA-repair and signalling processes. NAD+ levels are understood to decline with age, which is why "raising NAD+" is a central longevity theme. See: What is NAD+? · Increase NAD+ naturally
NMN Nicotinamide Mononucleotide
A direct precursor to NAD+ — a molecule the body can convert into NAD+. NMN is the most-studied NAD+ precursor in the supplement space. See: What is NMN? · Best NMN supplement UK
NR Nicotinamide Riboside
Another NAD+ precursor and a form of vitamin B3. NR sits one step further back than NMN in the NAD+ pathway; the two are often compared. See: NMN vs NR
NMNH Reduced NMN
The reduced form of NMN. It is a newer, less-researched precursor that has attracted interest for its potential to raise NAD+, though human data are limited. See: NMN vs NMNH
Nicotinamide Niacinamide
A form of vitamin B3 and a building block within the NAD+ salvage pathway. It is widely used in nutrition and skincare.
Niacin Vitamin B3
The classic form of vitamin B3, a recognised dietary nutrient that contributes to normal energy-yielding metabolism and feeds into NAD+ production.
NAD+ salvage pathway
The recycling route cells use to regenerate NAD+ from breakdown products such as nicotinamide, rather than building it from scratch. It is the main day-to-day source of cellular NAD+.
Section 02

The cellular mechanisms of ageing

The biology researchers point to when they talk about how and why we age.

Sirtuins
A family of enzymes (SIRT1–SIRT7) involved in DNA repair, metabolism and cellular stress responses. Sirtuins require NAD+ to function, which links them to the NAD+ longevity story.
AMPK AMP-activated protein kinase
A cellular energy sensor sometimes called a "metabolic master switch." When activated, it shifts cells toward energy production and maintenance. It is the main pathway associated with berberine.
mTOR mechanistic target of rapamycin
A central regulator of cell growth and protein-building. Dialling mTOR up favours growth; dialling it down is associated with maintenance and autophagy — a balance much discussed in longevity research.
Autophagy
The cell's self-cleaning process, in which damaged proteins and worn-out components are broken down and recycled. It is one of the most discussed longevity mechanisms and is associated with fasting and with spermidine.
Mitophagy
A specialised form of autophagy that clears out damaged mitochondria, helping maintain a healthy cellular power supply.
Cellular senescence
A state in which cells stop dividing but resist dying, accumulating with age. These "zombie cells" can release inflammatory signals, which is why clearing them is an active research area.
Senolytics
Compounds studied for their potential to selectively clear senescent cells. Plant flavonoids such as fisetin and quercetin are the most-discussed natural candidates; human evidence is still emerging.
Telomeres
Protective caps at the ends of chromosomes that shorten each time a cell divides. Telomere length is one of several markers studied in relation to biological ageing.
Mitochondria
The "powerhouses" of the cell that generate most cellular energy (ATP). Mitochondrial function is closely tied to NAD+, CoQ10 and overall vitality.
Oxidative stress
An imbalance between reactive oxygen species (free radicals) and the body's antioxidant defences. Antioxidants such as glutathione and CoQ10 are studied in this context.
Hallmarks of ageing
A widely cited scientific framework describing the core biological processes that drive ageing — including genomic instability, telomere attrition, loss of proteostasis, mitochondrial dysfunction and cellular senescence.
Section 03

Metabolic & blood-sugar terms

The vocabulary around metabolism, appetite and the "nature's Ozempic" conversation.

Berberine
A plant alkaloid researched for metabolic support, working mainly through the AMPK pathway. It is the most-discussed natural metabolic ingredient. See: What is berberine? · Berberine benefits
Dihydroberberine DHB
A more bioavailable derivative of berberine, absorbed more efficiently so smaller doses can be used. See: Dihydroberberine vs berberine
GLP-1 Glucagon-like peptide-1
A gut hormone released after eating that supports blood-sugar regulation and signals fullness. GLP-1 medications mimic it; "natural GLP-1 support" means diet and ingredients that work with your own response. See: Natural GLP-1 supplements · Berberine & GLP-1
Insulin sensitivity
How responsive your cells are to insulin. Greater sensitivity means the body manages blood glucose more efficiently — a key theme in metabolic health.
Blood glucose
The amount of sugar circulating in the blood. Keeping it stable, rather than spiking and crashing, underpins steady energy and metabolic wellbeing.
Metformin
A prescription medicine for blood-sugar management, often referenced in longevity discussion because, like berberine, it engages the AMPK pathway. Berberine is a food supplement and is not a substitute for prescribed medication.
Section 04

Key actives & ingredients

The compounds you'll see across longevity and wellness stacks.

Resveratrol
A polyphenol found in grapes and red wine, often paired with NMN because it is studied alongside the sirtuin pathway. Trans-resveratrol is the more bioavailable form.
Quercetin
A plant flavonoid with antioxidant properties, studied both for general wellbeing and as a senolytic candidate, frequently alongside fisetin.
Fisetin
A flavonoid found in strawberries and apples, among the most-discussed natural senolytics in current longevity research, though human data remain limited.
Spermidine
A polyamine found in foods such as wheat germ and aged cheese, studied for its association with autophagy. A trending longevity ingredient in 2026.
CoQ10 Coenzyme Q10
A compound central to mitochondrial energy production and a fat-soluble antioxidant. Levels naturally decline with age.
Ubiquinol
The active, reduced form of CoQ10, generally considered more bioavailable than ubiquinone, particularly relevant for older adults.
Glutathione
Often called the body's "master antioxidant," a molecule central to neutralising oxidative stress and supporting cellular detoxification.
TUDCA Tauroursodeoxycholic acid
A bile acid studied for its role in liver and cellular health, of growing interest in the longevity and gut-health space.
PQQ Pyrroloquinoline quinone
A compound researched in relation to mitochondrial support, sometimes combined with CoQ10 and NMN.
AHCC Active Hexose Correlated Compound
A mushroom-derived compound (from shiitake mycelia) widely researched for immune support. See: What is AHCC? · AHCC benefits
Section 05

Supplement science & quality

The terms that separate a trustworthy supplement from a poor one.

Bioavailability
The proportion of an ingredient that is actually absorbed and available for the body to use. Two products at the same dose can differ hugely in bioavailability.
Phytosome
A delivery technology that binds a plant compound to a phospholipid to improve absorption — used, for example, in berberine phytosome formulas.
Liposomal
A delivery format that encloses an ingredient in tiny lipid spheres (liposomes) to protect it through digestion and improve uptake.
Certificate of Analysis COA
A lab document verifying a batch's identity, potency and purity (including contaminant testing). A COA available on request is a key trust signal. Vitality provides a COA on request for every batch.
ISO/IEC 17025
The international standard for the competence of testing laboratories. Batch testing by an ISO/IEC 17025-accredited lab — as Vitality uses — is a strong marker of reliable results.
GMP Good Manufacturing Practice
A quality framework governing how supplements are produced, ensuring consistency, cleanliness and accurate labelling.
Third-party testing
Independent laboratory testing carried out by an organisation separate from the manufacturer, providing an unbiased check on quality and purity.
Food supplement
The UK regulatory category for products like NMN, berberine and AHCC. Food supplements are not medicines and cannot carry unauthorised health claims.
Half-life
The time it takes for the level of a compound in the body to fall by half — useful for understanding dosing frequency and timing.
Common questions

Glossary FAQ

NAD+ is the active coenzyme cells use; NMN and NR are precursors the body converts into NAD+. NMN is one step closer to NAD+ than NR. See What is NAD+? and NMN vs NR.
A senolytic is a compound studied for its potential to clear senescent ("zombie") cells that accumulate with age. Fisetin and quercetin are the most-discussed natural candidates; the evidence in humans is still early.
Because the dose on the label isn't the dose your body uses. A poorly absorbed ingredient at a high dose can deliver less than a well-absorbed one at a lower dose — which is why forms like phytosome, liposomal and dihydroberberine exist.
Look for independent (third-party) batch testing, ideally by an ISO/IEC 17025-accredited lab, a Certificate of Analysis available on request, clear dosing, and transparent UK manufacturing.
No. In the UK, ingredients like NMN, berberine and AHCC are sold as food supplements, not medicines, and carry no authorised health claims. Always consult a healthcare professional before starting any supplement.

Explore the guides

Every term here links to a deeper, evidence-led guide. Start with our most-read pillars on NAD+, NMN and berberine.

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About this reference. This glossary is compiled and maintained by the Vitality Supplements Editorial Team, a UK food-supplement manufacturer. Every batch we produce is independently tested by an ISO/IEC 17025-accredited laboratory, with a Certificate of Analysis available on request.

Definitions are for general education about food supplements and longevity science and are not medical advice. The ingredients described are sold as food supplements in the UK and carry no authorised health claims. Always consult a qualified healthcare professional before starting any supplement, particularly if you are pregnant, breastfeeding, taking medication or managing a health condition. References available on our research references page.