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.
Hypercalcemia may develop both spontaneously and as a result of androgen therapy in women with disseminated breast carcinoma. If it develops while on this agent, the drug should be discontinued. Caution is required in administering these agents to patients with cardiac, renal or hepatic disease. Cholestatic jaundice is associated with therapeutic use of anabolic and androgenic steroids. Edema may occur occasionally with or without congestive heart failure. Concomitant administration of adrenal steroids or ACTH may add to the edema. In children, anabolic steroid treatment may accelerate bone maturation without producing compensatory gain in linear growth. This adverse effect may result in compromised adult stature. The younger the child the greater the risk of compromising final mature height. The effect on bone maturation should be monitored by assessing bone age of the wrist and hand every six months. This drug has not been shown to be safe and effective for the enhancement of athletic performance. Because of the potential risk of serious adverse health effects, this drug should not be used for such purpose.