T Nation


Tell me about metformin. How does it work? I use 4 tabs a day. It gives me an incredible pump during my workouts. It also seems to decrease the apetite. Why is this?

The primary therapeutic effect of metformin is thought to be decreased gluconeogenesis in the liver. In addition, your “pump” is the result of metformin’s ability to improve utilization of glucose in skeletal muscle and adipose tissue by increasing cell membrane glucose transport. I’m not certain why your appetite is reduced, but my guess would be that the reduction in blood glucose levels alleviates the various effects that carbohydrates have on the appetite.

Depends on who you ask ,some say it sensitises insulin receptors on muscle cells , others say it slows the rate of which your liver releases glucose into your circulation, maybe it’s a little of both.The pumps I don’t know , but your appetite is reduced from lowering your insulin levels.

Metformin doesn’t directly affect insulin levels, i.e., it may indirectly do through the lowering of blood glucose levels, but only if those levels were elevated to begin with. It may also indirectly lower insulin levels through its effect on insulin sensitivity, but again only if those levels were elevated to begin with. In any event, the presence of insulin does not have a significant effect on the appetite; rather, it’s the effect of carbohydrates on certain neuroreceptors as well as on the production of certain neurotransmitters. (An example of this is the fact that diabetics – who essentially suffer from an absence of insulin – almost always display a markedly increased appetite after the onset of the disease.)

Good point!