ade by GENEXPHARMA. (This item ships from Canada!)
2.5mg x 40 tablets.
Letrozole is a third generation aromatase inhibitor. Like most aromatase inhibitors it was developed to fight breast cancer by inhibiting aromatization via the aromatase enzyme. It is similar to arimidex, however letrozole is much more potent in it’s ability and is used primarily when other treatments such as selective estrogen receptor modulators have failed to produce results. This is why the majority of the research about letrozole has been conducted on post-menopausal women, but of course some of the findings can be translated over for the benefit of athletes.
In terms of how these effects can be used to the benefit of bodybuilders and strength athletes, letrozole is primarily used to ward any estrogenic side effects caused by the administration of anabolic steroids. Letrozole has been show to have the capability of reducing the level of estrogen in users’ bodies by up to 96-98%. This would seemingly be enough in itself to make the compound a desirable one with which steroid users would be interested in. However letrozole also has been shown to increase the amount of lutenizing hormone, follicle stimulating hormone, and sex hormone binding globulin in users (1). When you combine these attributes with the fact that it will help protect against gynocomastia, water retention and other estrogenic side effects letrozole obviously can fulfill many users’ needs.
There are some animal studies that have suggested that letrozole can help to reduce or even eliminate pre-existing gynocomastia as well (2). Of course there are some limits to this research as it has never been conducted using human subjects but it does demonstrate that there may be a mechanism by which this could occur. Anecdotally some users have reported that they have experienced a reduction in their own pre-existing gynocomastia, but of course these reports have their limits as they were not conducted with the scientific controls in place.
Interestingly, it takes approximately 60 days to get a steady blood plasma level of letrozole once administration of the drug begins (3). This may necessitate that a user begin using the compound prior to beginning their cycle if they wish for the effects to be at full strength once their cycle begins. This may also hinder the ability of the compound to respond quickly if a user begins administration of the drug to counteract some side effects that have appeared quickly.