What Is Longevity

Metabolic Pathways

The cellular signaling levers that pharma and lifestyle interventions target to influence aging: mTOR, AMPK, sirtuins, the NAD+ pathway, autophagy activation, and the caloric-restriction mimetics that act on them.

Topics in Metabolic Pathways

AMPK Activation

AMPK activation triggers cellular energy sensing and metabolic repair pathways linked to longevity, fat oxidation, and autophagy. Here is how it works.

Autophagy Activation

Caloric Restriction Mimetics

Caloric restriction mimetics are compounds that activate the same cellular pathways as reduced calorie intake, targeting autophagy, AMPK, and sirtuins without actual fasting.

FOXO Transcription Factors

FOXO transcription factors regulate stress resistance, autophagy, and DNA repair. Learn how these proteins connect to lifespan and metabolic health.

Glycolysis vs Oxidative Phosphorylation

Glycolysis and oxidative phosphorylation are the two core ATP-generating pathways in human cells, with distinct roles in aging, disease, and metabolic health.

IGF-1 and Growth Hormone Axis

The IGF-1 and growth hormone axis regulates cell growth, metabolism, and tissue repair. Learn its mechanisms, role in aging, and what the evidence shows.

Insulin Signaling Pathway

The insulin signaling pathway governs how cells absorb glucose and regulate growth. Learn its mechanisms, links to aging, and what influences its function.

Ketogenesis (Metabolic Pathway)

Ketogenesis is the metabolic pathway that converts fatty acids into ketone bodies for fuel. Learn the biochemistry, triggers, longevity links, and what to track.

Methionine Restriction

Methionine restriction reduces intake of a sulfur amino acid linked to aging pathways, with animal evidence of lifespan extension and metabolic benefits.

Mitochondrial Biogenesis

Mitochondrial biogenesis is the process cells use to grow and divide mitochondria, sustaining energy production and metabolic health as organisms age.

mTOR Pathway

The mTOR pathway controls cell growth, protein synthesis, and autophagy. Learn how it connects to aging, caloric restriction, and rapamycin research.

NAD+ Pathway

The NAD+ pathway governs cellular energy production, DNA repair, and aging. Learn how NAD+ declines with age and what interventions aim to restore it.

Nrf2 Pathway

The Nrf2 pathway activates your cells' internal antioxidant and detoxification defenses. Learn how it works, what activates it, and its role in aging.

PI3K-Akt Pathway

The PI3K-Akt pathway controls cell growth, metabolism, and survival. Learn how its activity shapes aging, cancer risk, and longevity interventions.

Polyamine Pathway

The polyamine pathway produces spermidine, putrescine, and spermine, small molecules that regulate cell growth, autophagy, and aging across tissues.

PPAR Pathways

PPAR pathways are nuclear receptor systems that regulate fat burning, glucose metabolism, and inflammation, with direct relevance to metabolic aging.

Sirtuins

Sirtuins are a family of enzymes that regulate DNA repair, metabolism, and stress resistance. Learn how they work, what activates them, and what the evidence shows.

Latest News in Metabolic Pathways

LifeSpan.ioFeb 23, 2026

How a Sirtuin Protects Against Brain Diseases

SIRT6, a sirtuin protein, protects against neurodegenerative diseases by maintaining nucleolar function and constraining protein synthesis, preventing the accumulation of misfolded proteins that drives age-related brain pathology. This mechanism represents a direct intervention point in proteostasis failure, a primary driver of cognitive decline.

Longevity.TechnologyFeb 18, 2026

Could PGC-1α hold the key to longevity?

PGC-1α, a transcriptional coactivator that regulates cellular energy metabolism and mitochondrial biogenesis, is emerging as a target for age-related disease intervention. Endurance Bio is advancing a small molecule (T-168) designed to upregulate PGC-1α, with Phase 2 trials underway in Parkinson's disease and potential applications across neurodegeneration, metabolic dysfunction, and frailty.

Wiley Aging CellFeb 18, 2026

SIRT6 Regulates Protein Synthesis and Folding Through Nucleolar Remodeling

SIRT6 maintains proteostasis by suppressing ribosomal gene expression and translation rates through nucleolar control. Without functional SIRT6, excessive protein synthesis overwhelms the folding machinery, leading to protein aggregation and accelerated neurodegeneration in aging models.

LifeSpan.ioApr 16, 2026

Targeting an Appetite Hormone Receptor for Stronger Muscles

Suppressing the ghrelin receptor (GHSR-1a) improves muscle function and reduces sarcopenia in aging mice through enhanced mitochondrial efficiency and altered muscle fiber composition. Pharmacological inhibition of this receptor produced similar benefits in older mice, suggesting a translatable approach to sarcopenia without extending lifespan.

Wiley Aging CellApr 16, 2026

Ghrelin Receptor Deletion or Pharmacological Inhibition Improves Muscle Function in Aging Male Mice

Blocking the ghrelin receptor improves muscle endurance and mitochondrial function in aging mice without affecting muscle mass or lifespan. Both genetic deletion and pharmacological inhibition restore markers of mitochondrial renewal, suggesting this pathway is a viable therapeutic target for age-related muscle decline.

LifeSpan.ioApr 16, 2026

Targeting an Appetite Hormone Receptor for Stronger Muscles

Inhibiting the ghrelin receptor (GHSR-1a) improves muscle strength, exercise capacity, and mitochondrial function in aging mice, reducing sarcopenia markers without extending lifespan. Pharmacological inhibition via PF-5190457 replicates these effects and represents a translatable therapeutic approach.