Detailed product information can be found here
To understand the mechanism of this drug’s action let’s clarify one of the main reason for the breast cancer occurring. Specialists claim that among postmenopausal women the main reason for the breast cancer is the estrogen which circulates in the blood and cause the occurring of malignant tumors or their growth increasing. These estrogens are produced in the adrenal glands of the female organism. Letrozole, which is the oral drug, is aimed at the inhibiting of these estrogens production or rather inhibiting the enzyme which is responsible for their production. Because of such inhibition, this preparation refers to the “anti-estrogen” medications.
Letrozole is also of particular interest to bodybuilders and athletes. First, it has been proven that this drug reduces the level of estrogen to 98% or more. Therefore, it is obvious that he is of great interest to bodybuilders. In fact, this drug reduces the amount of estrogen in the body, eliminates the side effects of steroids, such as water retention, gynecomastia and acne.
This makes letrozole the best antiestrogen on the market, when used even in very complex cycles. Also, if you participate in bodybuilding competitions, letrozole will help you to have dry and striated muscles.
One more fact that is similar for both of these drugs is that they are prohibited to be used in combination with Tamoxifen as it can decrease their effect significantly.
Letrozole is an antitumor agent in the group of non-steroidal aromatase inhibitors (estrogen synthesis inhibitor).
Androgens (primarily androstendione and testosterone) are the main source of estrogen. In cases where tumor growth depends on the presence of estrogens, the removal of stimulant action may be a method of inhibiting the development or progression of cancer. Estrogen is predominantly formed by the participation of aromatase, an enzyme that transforms endogenous androgen into estrone and estradiol. By selective inhibition of aromatase, it is possible to block estrogen biosynthesis in peripheral and tumor tissues. Letrozole is a non-steroidal high-selectivity inhibitor (superior to fadrozole, anastrozole, etc.) versus aromatase. The preparation inhibits aromatase by concurrent coupling with the cytochrome P-450 iron with diminished estrogen synthesis in tissues.
When administering the preparation at doses of 0.5 mg or more in most cases, the concentration of estrone and estrone sulfate was lower than the susceptibility threshold of the hormone determination method, which reveals a marked inhibition of estrogen synthesis.
Side effects like anorexia, increased appetite, hypercholesterolemia, depression, headache, dizziness, nausea, vomiting, dyspepsia, constipation, diarrhea, alopecia, rash (including erythematous, maculopapular vand vesicular rash) arthralgia, myalgia, bone algae, osteoporosis can still occur.
The effective dose for letrozole is 2.5 to 5 mg per day. If you exceed this dose, there may be a risk of loss of libido. More if you keep your estrogen levels too low for too long you will end up weakening your immune system.
It should be noted that letrozole, may also be used in post-cycle therapy for a raise LH and FSH levels (hormones which produce testosterone).
There are no cases of overdose. No specific treatment methods are known in case of overdose, therapy should be symptomatic and maintenance of vital functions.