As it pertains to fat loss steroids and almost any topic regarding performance enhancing drugs (PED’s) you will find these two hormones to be atop the list of most all discussions. Let’s be brief and concise; HGH or Human Growth Hormone is not a steroid of any form, it is a peptide hormone and belongs to a class of its own. While one of the best PED’s for body fat reduction it is not applicable to this discussion of fat loss steroids since it is not a steroid. Testosterone however, that is another story; there is no anabolic androgenic steroid on earth quite as remarkable as testosterone. While some steroids may indeed be more potent in varying degrees, on the whole and in an all-around manner Testosterone is the most effective and efficient. The question remains, how does it stack up in the fat burning category and the answer is simple; perfectly. While excess levels will not burn fat cells in the most direct sense, increased testosterone levels allow us to accomplish the previous listed function in the best manner possible.
It should be noted that in theory if one was to consistently suppress your natural estrogen levels for a long period of time, this would negatively impact your health, including your cholesterol. Due to the ability of Letrozole- to inhibit estrogen so much, this should definitely be a concern to most users. However the research that has focused on the relationship between use of letrozole and cholesterol levels is rather inconsistent in it's findings. Many studies have concluded that the compound is detrimental to both a user's HDL and LDL cholesterol levels, while other research has found no link. Obviously individuals are best served to monitor their cholesterol while using any compound via blood tests however barring that, letrozole should simply not be run for extended periods of time if at all possible. Doing so could cause serious medical complications.
Along with the issues related to blood lipids is the fact that many users complain that their libido is dramatically reduced when using the compound. This is related to the fact that estrogen is partly responsible for the regulation of an individual's sex drive. Since Letrozole- is so potent it can often drive estrogen levels too low and this inhibits a user's libido. To avoid this users can lower dosages, but some anecdotally report that even extremely low doses of the drug can cause problems. If this is the case a less potent compound such as exemestane or anastrozole may be a more appropriate option.
Due to its chemical structure nandrolone is weakly exposed to aromatase (only 20% of the aromatizing activity of testosterone). However, not estrogenic effects are its main concern: nandrolone has a potent progestogenic activity (20% of progesterone). While binding to progestogenic pituitary receptors nandrolone causes increased production of prolactin, which in effect is very similar to estrogen: its effect presents in reducing testosterone production, increasing fat mass and in gynecomastia. To prevent these side effects prolactin inhibitors (cabergoline) shall always be at hand when on nandrolones cycle.