AMPK

The cell's low energy sensor, activated when ATP falls, which switches metabolism from building to burning and turns on repair processes.

What it senses

AMPK monitors the ratio of AMP and ADP to ATP, which is a direct readout of whether a cell is running short on energy. When energy falls, AMPK activates, increases glucose uptake and fat oxidation, promotes mitochondrial biogenesis, and inhibits mTORC1, which permits autophagy.

Functionally it is the counterweight to mTOR. One says build, the other says conserve and repair.

What activates it in practice

Exercise is the strongest and best documented activator in humans, particularly sustained work that depletes muscle energy stores. Energy restriction does it. Metformin activates it indirectly, and berberine appears to share part of that mechanism.

This is the pathway invoked in most supplement marketing about metabolic health. Activation in a cell culture dish is easy to demonstrate and tells you very little about what a capsule does in a person.

The honest limit

AMPK activation is a mechanism, not an outcome. Metformin has extensive human outcome data in diabetes, and the question of whether it benefits people without diabetes is what the TAME trial was designed to answer and has not yet resolved.

For everyone else the reliable AMPK intervention is training. It is also the one with mortality data behind it.

Baseline does not sell AMPK activators. The mechanism is here because it is the honest explanation behind a lot of supplement copy.

References

  1. Herzig S, Shaw RJ. AMPK: guardian of metabolism and mitochondrial homeostasis. Nat Rev Mol Cell Biol. 2018.
  2. Foretz M, et al. Metformin: from mechanisms of action to therapies. Cell Metab. 2014.
  3. Barzilai N, et al. Metformin as a tool to target aging. Cell Metab. 2016.