Femara (Letrozol) is a type II (non-steroidal) third generation aromatase inhibitor. Medically, this medicine is used in treatment of certain type of breast cancer in women after menopause. It’s also helpful to stop the cancer from returning. Sometime increased no of estrogens (natural hormones) become the reason of certain types of breast cancers and this medication decreases the production of amount of estrogens. Therefore, it helps to slow or reverse the growth of these breast cancers. A given tumor must be diagnosed first as estrogen receptor positive or estrogen receptor unknown in order to prescribe it for the patients. In the world of bodybuilders and athletes, this drug reduces or eliminates overload estrogens due to the use of aromatizing steroids. Background Letrozol was produced by the pharmaceutical company Novartis and originally sold under the brand name Femara and it was patented on July 25th, 1997.Action Letrozol is known as a type II aromatase inhibitor. It means, in simplest terms, that it gets attached to the aromatase enzyme and stops it from converting androgens to estrogens. If we explain it in some complex and technical way, the activity of aromatase enzymes converts the androgens into estrogens. What do the Latrozol is that it binds to the heme of the relevant cytochrome P450 unit and inhibits the production of estrogens. Technical Data Letrozol at present is the strongest aromatase inhibitor available. In women suffering from breast cancers, this medication has the ability to reduce estrogen levels by 98% or more than it, which is the wonderful effect of it in this matter and there are so many other advantages of it for women beyond the elimination of the estrogens. In one male test subject, Letrozol reduced the quantity of estrogen levels to undetectable levels (2). Another clinical study was done on a young and an elderly men about the efficiency of the drug and found an amazing result. The intravenous administration of Letrozol reduced the estrogen levels by 46% in young men and 62% in elderly men. It raises the levels of testosterone in male subjects. The efficiency of Letrozol was studied in men and it was found that it increases the LH levels to a 339 and 323% in the young and 323% in the elderly men and testosterone by 146 and 99%, respectively. Letrozol was also able to produce a peak LH response to GRH (Gonadatropin). In a similar study, 45% testosterone level was increased only by the 0.02 g of Latrozol only after 2 days. According to one study on men, that the same twenty micrograms of Latrozol was enough to reduce estrogen levels by roughly a third. It has a half life of 2-4 days and for getting steady blood plasma level, it should be taken for up to 60 days. In males, it was used in removing gynecomastia. As estrogen is also a factor for stopping linear growth in the bones and letrozol is being used to solve the bone growth problem seen in children. The performance of this drug has been reported positively by the users in the world of bodybuilding and bodybuilders prefer to use this drug with confidence. Elimination of estrogens from the body is not the main aim of using such drugs but its main aim to lower the level of estrogen to the proper level to control the situation and side effects. Estrogen is necessary for healthy immune function, cognitive function and for the healthy cholesterol levels and for so many other problems of muscle growth. I am in favor of using this drug personally as compared to other such drugs. Letrozole simply reduces the levels of estrogen too low to function well and properly as it should be. In my own particular case, I had been using it in past 2.5mgs /day. I wanted to eliminate gyno (which it did). I started at a dose of 2.5mgs/day and reached to its reduced dose limit of 0.25mgs every week and continued its use until gyno showed no signs of coming back. The steroid users, who use Letrozol for recreational use, have to suffer a lot of problems. People can use it effectively if they keep their dose 0.25mg instead of 2.25 (clinical dose). However, it is a better choice for an anti-estrogen and such a low dose of Letrozol happen to make it a very good economic choice as compared to other aromatase inhibitors. It’s the necessity of pre-contest bodybuilders to eliminate water retention to gain ripped look to compete in today’s bodybuilding world. However, in my experience, last 4-6 weeks are important for using Letrozol to get rid of excessive estrogens and water retention to normalize the body. Letrozol is the chemical name of active ingredient in Femara, which is a registered trademark of Novartis Pharmaceuticals Corporation in the United States and/or other countries.