Very good question. But there is one aspect to consider, which I left out to avoid a too complicated post. High Cortisol AND high T4 (or high T3 in case you are taking T3) boost overall metabolism, which boosts testosterone metabolism (simply put, T-sensitivity, see below). So, here is the slow motion of what happens by boosting a male’s cortisol:
Step 1. Suppose that you increase cortisol.
Step 2. This causes a reduction in T levels. Your libido decreases by 10 points of an arbitrary scale. Overall change in libido at this point = -10.
Step 3. Your hypothalamus, realizing this drop in T, reduce E2 or SHBG in an attempt of your body to reach the (degraded) homeostasis that was present before increasing cortisol. Your libido increases by 10 points. Overall change in libido at this point = -10 + 10 = 0.
Step 4 (the critical one). Your body, realizing an increase in cortisol, may or may not increase the production of T4, in an effort to have enough thyroid hormone to match the higher level of cortisol – because T3 and cortisol work together to increase metabolism.
Step 4a: if your body increases the production of T4 by a sufficient amount to match the extra cortisol, then your overall metabolism increases, resulting in extra energy. Also, according to chilln, an increase in overall metabolism boosts T metabolism, effectively resulting in a higher sensitivity of the androgen receptor to T. This is also partially confirmed by awor, who said that T3 increases the gene expression of the receptor. Therefore, your libido increases by, let’s say, 5 points. Overall change in libido = -10 + 10 +5 = +5.
Step 4b: if your body does not increase the production of T4 by a sufficient amount to match the extra cortisol (pretty common case), then you will have symptoms of high cortisol or low pregnenolone, depending on which method you used to boost cortisol.
So, if you end up being in case 4b, which is pretty common, then you will not benefit from a higher cortisol. But, if you end up being in case 4a (which is guaranteed, if you take a thyroid medication), then you will improve.
For hypogonadal men (i.e. with low Total Testosterone), the reasoning is the same. It depends on what their hypothalamus decides to do in step 4.
Agreed. But, increasing T without boosting cortisol and thyroid hormones adequately can be detrimental, as shown by many of this board’s members. On the other hand, most of those who concurrently boosted overall metabolism and testosterone levels have been successful.