The action of insulin is counterregulated by glucagon, epinephrine (adrenaline), norepinephrine (noradrenaline), cortisol, and growth hormone.
[1] In healthy people, counterregulatory hormones constitute a principal defense against hypoglycemia, and levels are expected to rise as the glucose falls.
As an example, the exercise-induced reduction in blood glucose is counterregulated by increases in levels of epinephrine, norepinephrine, cortisol, and growth hormone.
The rise in blood concentrations of these counterregulatory hormones is dependent upon both exercise intensity and duration, and is proportional to the rate of glucose uptake by the contracting skeletal muscle.
[2] In the reproductive system, inhibins and follistatin counterregulate activins, to control follicle-stimulating hormone and so the release of gonads.