Letrozole is an anti-estrogen of the Aromatase Inhibitor (AI) family and is one of the most potent and powerfully effective of all AI’s. In fact, its potency is sometimes too much for some to handle when used for off label use. Letrozole first gained U.S. FDA approval in 1997 and would hit the market under the brand name Femara through Novartis. Although Femara is the dominating trade name of the AI, unlike most AI’s it is the only one generally known by its chemical name Letrozole far more commonly than its dominating brand name. Letrozole was first developed in an effort to combat breast cancer in post-menopausal women. In fact, it would prove to be virtually identical to the already popular AI in Arimidex (Anastrozole). While intended for breast cancer treatment, like many AI’s, it has found a welcomed home among anabolic steroid users. Letrozole is one of the most commonly used anti-estrogens among steroid users during steroid use to combat possible estrogenic related side effects. It is so effective as an anti-estrogen in this regard many anabolic steroids have effectively reversed gynecomastia symptoms with Letrozole.

Letrozole Functions & Traits:
Letrozole is an AI, which holds the purpose of blocking the aromatase enzyme, which is in turn responsible for the production of estrogen. By inhibiting estrogen production, this lowers total serum estrogen levels in the body. This will be useful to the breast cancer patient on the basis of such cancer often feeding off the estrogen hormone. It will be beneficial to the anabolic steroid user as excess estrogen often leads to some of the most commonly associated side effects of anabolic steroid use. Letrozole also carries the ability to increase natural testosterone production through an increase in Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). There have been physicians who have chosen Letro as it’s often known to treat low testosterone conditions, but this is normally not the preferred method of treatment. Without question, when it comes to low testosterone treatment exogenous testosterone is generally the only thing that makes sense. However, Letrozole can be useful in such a plan in conjunction with exogenous testosterone in order to combat possible side effects. We will look into this in the effects section.

Effects of Letrozole:
Letrozole as an anti-estrogen is extremely beneficial to breast cancer patients. Many forms of breast cancer actively feed off the estrogen hormone. By inhibiting the production of estrogen, which in turn lowers the amount of circulating estrogen in the body, this has the ability to starve the cancer. For years Nolvadex was the preferred form of treatment for this purpose. Nolvadex actively binds to the estrogen receptor, thereby preventing estrogen from binding. However, it does not inhibit or lower production. Nolvadex is still extremely valuable in breast cancer treatment plans, but many physicians, especially in extreme cases have begun to use AI’s first. Once the cancer is in remission, at this stage a SERM like Nolvadex may replace the AI in an effort to protect against the cancer reappearing. For the anabolic steroid user, the same anti-estrogenic effect provided by Letrozole is tremendously beneficial. Many anabolic steroids have the ability to increase estrogen levels due to testosterone’s interaction with the aromatase enzyme. As estrogen levels rise, this can lead to gynecomastia and excess water retention. If water retention becomes severe, this can in turn promote high blood pressure. While many anabolic steroids have the ability to aromatize and promote an increase in estrogen, not all anabolic steroids carry this ability. However, many common steroids carry this ability including Methandrostenolone (Dianabol) as well as all forms of testosterone. The Nandrolone (Deca Durabolin, Durabolin, NPP, etc.) and Boldenone (Equipoise) hormone also carry the ability to aromatize to a degree. Nandrolone will aromatize at approximately 20% the rate of testosterone and Boldenone at approximately 50%. While both aromatize significantly less than testosterone, it is enough to promote estrogenic related side effects. The probability is increased with Nandrolone as it carries a strong progestin nature. Progesterone has the ability to stimulate the estrogenic mechanism and can lead to gynecomastia. AI’s like Letrozole can be useful when using all the aforementioned steroids. By including Letrozole in a cycle that contains aromatizing anabolic steroids, this can prevent the estrogenic related side effects. This will protect the individual from gynecomastia and water retention. Further, while many steroids can promote high blood pressure despite aromatization, an AI will improve the individual’s odds when water retention is the culprit. Heavy excess water retention is normally the number one cause of high blood pressure among steroid users. Undeniably, AI’s like Letrozole are the most effect means at combating estrogenic related side effects. However, they can also have a negative impact on cholesterol. Alone AI’s do not appear to have a strong, negative effect on cholesterol, but when coupled with an aromatizing steroid like testosterone the adverse cholesterol effect is enhanced. For this reason, many will find SERM’s like Tamoxifen Citrate (Nolvadex) should be their first choice in estrogen protection. SERM’s will not negatively affect cholesterol; in fact, SERM’s, while anti-estrogenic, actively act as estrogens in the liver, and in turn, promote healthier cholesterol levels. We’ll look at this in more detail in the side effect section, and while Letrozole can be used without an adverse cholesterol effect, it will take some effort on your part. With its ability to promote natural testosterone production, Letrozole is often an appealing choice for Post Cycle Therapy (PCT) plans. This can also make it appealing for low testosterone treatment, but it’s often not enough. However, for PCT purposes, while it can be effective it’s generally not recommended. The primary purpose of PCT is stimulating natural testosterone production, which Letrozole can do very well. However, part of the purpose of PCT is also normalization, which will be difficult with severely suppressed estrogen levels. Estrogen is an important hormone as it promotes a stronger immune system and healthier cholesterol levels. For the anabolic steroid user, his best bet for PCT is sticking with SERM’s for his natural testosterone production needs.

Side Effects of Letrozole:
The side effects of Letrozole will cover a wide breadth and will be very similar to Arimidex. Both weakness and fatigue are two of the most common side effects of Letrozole use. However, for the anabolic steroid user this will normally not be an issue. The use of anabolic steroids should prevent such states so as long as estrogen suppression isn’t taken too far. The exception would be its use during a hard bodybuilding contest prep cycle. During a harsh bodybuilding diet, the individual will normally be very weak and fatigue at the end of his diet due to tremendously intense training and very low caloric intake. Beyond possible energy issues, the most common side effects of Letrozole use include:

Headaches
High Blood Pressure
Hot Flashes
Joint Pain
Depression

Letrozole has also been shown to have the ability to notably decrease bone mineral content, which could increase the risk of osteoporosis. This should, however, not be a big risk for the anabolic steroid as most steroids have the ability to promote bone mineral content to a degree, especially Nandrolone. As with all medications and anything we put into our body, the side effects of Letrozole will largely surround possible and not guaranteed. We are all different and respond to varying substances differently. This is something you need to keep in mind, and if the side effects of Letrozole prove to be too much to handle, alternative medications should be looked at. The final side effect of Letrozole surrounds cholesterol, specifically a reduction in HDL cholesterol. Alone it does not appear to have a strong, statistical impact, but for the anabolic steroid user this can be a concern. Many anabolic steroids already have the ability to negatively affect cholesterol, and when conjoined with an AI it appears to be greatly exasperated. Studies have shown that therapeutic doses of testosterone have very little negative effect on cholesterol but the same doses can suppress HDL cholesterol by as much as 25% when combined with an AI. When testosterone is administered at a supraphysiological level, a minimal level of HDL suppression is normally expected. When the same dosing level is conjoined with an AI data shows that a 20% or greater suppression of HDL cholesterol is a very real possibility. Due to the possible adverse effects on cholesterol, especially for the anabolic steroid user, a cholesterol friendly lifestyle becomes imperative. A healthy lifestyle will greatly revolve around your diet. Simple sugars and saturated fats should be limited and omega fatty acids should be a large part of your diet. Daily fish oil supplementation is recommended. Many may also find a cholesterol antioxidant supplement to be useful. Further, implementing plenty of cardiovascular activity into your routine is very important. Some type of daily cardiovascular activity is advised. Because of the potential cholesterol issues, many anabolic steroid users will need to use SERM’s to combat estrogenic side effects when possible. SERM’s won’t always get the job done, but they can work and will work a lot better than many steroid users believe. If an AI is needed, some have suggested that a daily dose of Nolvadex at 10mg per day with your AI could help protect cholesterol levels due to SERM’s actively promoting healthier cholesterol levels.