I have been taking Isocort for about three years and didnt think it was working as II still have what appears to be severe adrenal fatigue.
When I stopped taking it because it did not appear to be helping, I began to develop very severe fatigue. Now that I have been on it a week or so, that fatigue has lessened.
It seems to me that the answer is it helps somewhat, but not nearly enough to resolve cortisol insufficiencies.