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.
As we discussed above, Dianabol carries a strong aromatizing nature, and is a C17-aa anabolic steroid; as such, its side-effects will revolve around these factors. As an aromatizing steroid, this means there can be a testosterone to estrogen conversion, and if estrogen levels go to high it can lead to some complications. When estrogen levels increase, the hormone can attach to the receptors and cause gynecomastia (male-breast enlargement) and it can also promote excess water retention and high blood pressure; Dbol is notorious for promoting high blood pressure. Needless to say, if you already suffer from high blood pressure you should not touch this steroid, but if it's healthy you'll need to ensure it stays this way. For this reason, in-order to combat and avoid these estrogenic side-effects of Dbol, the use of an Aromatase Inhibitor (AI) is often advised. It shouldn't be too hard to see how this can help; after all, an AI inhibits aromatase, but it goes a step further by reducing the body's total estrogen levels. Of course, and this cannot be overstressed, you must keep your doses at a responsible level; most will need at least 20mg per day for any anabolic promotion, with a maximum dosing of 50mg per day. It should be noted; if you've never used this steroid before, you should not start with a high end dose; start low and see how you respond.