The hallmarks of aging explained simply

What are the hallmarks of aging?

The hallmarks of aging are a shared checklist of the fundamental things that go wrong as we age. Proposed in an influential 2013 review, they gave the whole field a common language: instead of arguing about what aging "is," scientists could point to specific, measurable processes and ask which interventions affect them.^[1] Each hallmark had to meet a bar — it should appear with age, accelerate aging when worsened, and slow aging when repaired.

The original nine hallmarks

The 2013 framework grouped the drivers of aging into nine categories. In plain language:

• Genomic instability — accumulating damage to your DNA.
• Telomere attrition — the protective caps on chromosomes shortening over time.
• Epigenetic alterations — changes in how genes are switched on and off (the basis of epigenetic clocks).
• Loss of proteostasis — the cell's protein quality-control system breaking down.
• Deregulated nutrient sensing — pathways like mTOR and insulin signaling drifting out of balance.
• Mitochondrial dysfunction — the cell's power plants becoming less efficient.
• Cellular senescence — "zombie" cells that stop dividing but linger and cause inflammation.
• Stem cell exhaustion — the body's repair reserves running down.
• Altered intercellular communication — cells signaling each other in increasingly disruptive ways.

The 2023 update: twelve hallmarks

A decade later, the same authors revisited the framework and expanded it to twelve, reflecting a decade of new evidence.^[2] The three additions are disabled macroautophagy (the cellular cleanup system failing), chronic inflammation — often called "inflammaging" — and dysbiosis, an unhealthy shift in the gut microbiome. Importantly, the update did not overturn the original nine; it broadened the map. The hallmarks are also described as interconnected, so worsening one tends to drag others down with it.

Well-established scientific framework

How the hallmarks connect to interventions

The reason this framework is useful to anyone thinking about longevity is that it turns a vague goal into targets. Interest in autophagy — and in fasting and mTOR inhibition as ways to stimulate it — maps directly onto the proteostasis and disabled-autophagy hallmarks; we unpack that in our guide to autophagy and fasting. Interest in senolytics targets the cellular-senescence hallmark by trying to clear those lingering "zombie" cells. Nutrient-sensing pathways are exactly what drugs like rapamycin and metformin act on. In other words, the compounds people debate are usually credible only insofar as they plausibly touch one of these hallmarks.

Why the framework matters

The hallmarks are a map, not a menu of proven cures. No single supplement addresses all twelve, and hitting a hallmark in a mouse is not the same as extending human healthspan. Still, the framework is the best way to judge a longevity claim: ask which hallmark a compound targets and how strong the human evidence is. That lens is exactly how we sort our roundup of the best longevity supplements by evidence, and it is the backbone of everything on the Rapamycin.store home page.

Frequently asked questions

What are the hallmarks of aging?

They are a set of biological processes that together drive aging. The original 2013 framework named nine; a 2023 update expanded it to twelve. Each hallmark is a distinct type of damage or dysfunction that accumulates over time and contributes to age-related decline.

How many hallmarks of aging are there?

Originally nine, proposed in 2013. In 2023 the same group expanded the list to twelve by adding disabled autophagy, chronic inflammation, and disruption of the gut microbiome (dysbiosis).

Why do the hallmarks of aging matter?

They give researchers a shared map of what aging is, so interventions can target specific mechanisms rather than vague 'anti-aging' goals. A compound is more credible when it plausibly addresses one of these hallmarks.

Can the hallmarks of aging be reversed?

Some can be slowed or partly improved in animal studies by targeting specific mechanisms, but reversing aging in humans is not established. The framework describes drivers of aging; it does not promise they can be undone.

What is the difference between the 9 and 12 hallmarks?

The 2023 version keeps the original nine and adds three: disabled macroautophagy (impaired cellular cleanup), chronic inflammation ('inflammaging'), and dysbiosis (an unhealthy gut microbiome). The update reflects newer evidence rather than replacing the old model.