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.
Sustanon 250 is a potent combination of four esters; testosterone propionate, testosterone phenylpropionate, testosterone decanoate and testosterone isocaproate. All four esters have different half lives; propionate has a half life of one day, phenyl propionate has a half life of 1 to 2 days, the half life of isocaproate is 4 to 5 days and that of decanoate is 7 to 8 days. The esters having short half life release quickly in the body but wear off quickly too thereby needing frequent doses. The esters with a long half cycle stay in the body for long but take time to become active. The different half cycles make Sustanon 250 quite useful and the users require just one dose per week. This is one of the reasons users buy Sustanon 250.