Guide
The hallmarks of ageing, explained
8 min read · last reviewed 22 August 2026
In 2013, researchers proposed a framework organising the biology of ageing into a set of interconnected hallmarks — updated in 2023 to twelve. It is genuinely useful scientific scaffolding. It is also, increasingly, a marketing device: targets a hallmark has become a way of sounding evidence-based without offering evidence. Both halves of that are worth understanding.
The twelve, briefly
The 2023 framework groups the hallmarks roughly by depth: primary hallmarks are causes of damage; antagonistic hallmarks are responses to damage that become harmful in excess; integrative hallmarks are where the damage lands.
- Genomic instability — accumulating DNA damage.
- Telomere attrition — the shortening of chromosome ends with cell division.
- Epigenetic alterations — drift in how genes are switched on and off. This is what epigenetic-clock age tests measure.
- Loss of proteostasis — declining quality control of proteins.
- Disabled macroautophagy — reduced cellular recycling; the hallmark spermidine research targets.
- Deregulated nutrient sensing — the pathways calorie restriction, rapamycin and metformin act on.
- Mitochondrial dysfunction — declining cellular energy production.
- Cellular senescence — damaged cells that stop dividing but linger, secreting inflammatory signals; the target of senolytics.
- Stem cell exhaustion — declining tissue repair capacity.
- Altered intercellular communication — the breakdown of signalling between cells and tissues.
- Chronic inflammation — low-grade, persistent inflammatory activation.
- Dysbiosis — deterioration of the gut microbial ecosystem.
What the framework is for
The hallmarks give researchers a common language and testable criteria: an ageing process should worsen with age, accelerate ageing when experimentally aggravated, and — ideally — slow ageing when targeted. They organise an otherwise sprawling field, and they are why you can meaningfully connect a supplement to a mechanism at all.
How marketing misuses it
Targets a hallmark of ageing is a mechanism claim, not an outcome claim. Thousands of compounds plausibly touch a hallmark in a dish; almost none have been shown to change anything measurable in a person. On this site, hallmark tags describe an intervention's proposed mechanism — they carry no evidential weight, and the claim-by-claim grades sit deliberately separate from them. If a product's strongest argument is the hallmark it targets, that is the tell: the human evidence is missing.