Letrozole (Letro) Explained

Background

Letrozole is a FDA approved drug designed for the treatment of metastatic breast cancer and post breast cancer surgery. Letro has also been used to increase fertility in women by stimulating the ovaries. It belongs to a class of drugs called Aromatize Inhibitors similar to aromasin and arimidex; however letro is considered the most powerful. Given its extreme anti-estrogenic mechanisms letro has been used in pretreatment for the termination of pregnancy.

Mechanisms of Action

In the bodybuilding world Letro is known to be the most potent and the most extreme Aromatize Inhibitor. It works very similar to the before mentioned aromasin and arimidex by binding to the aromatize enzyme therefore inhibiting the conversion of androgens to estrogen.  Letro utilizes a different protein when binding to the aromatize enzyme which is what separates it from the other AI’s. This is achieved via binding to the cytochrome P450 (a hemoprotein) enzyme which results in the reduction of estrogen synthesis in all bodily tissues.

Usage in Bodybuilding

The primary use of Letro is keeping estrogen levels in balance when running an anabolic steroid cycle. However letro is usually not the first choice of an AI on cycle because of how powerful it is, thus users can easily crash estrogen levels if used incorrectly. Remember, males require a small amount of estrogen in the body or else they can experience serious side effects such as loss of libido, lethargy, joint pain to name a few.

The next use of Letro is in the treatment of the infamous estrogenic side effect gynecomastia (enlargement of the male breast tissue). Since gyno is primarily a high estrogen related side effect we can understand why letro is a favorite for users to combat this. Not only will letro significantly lower estrogen levels and directly in breast tissue, but also begins to work extremely quick. Just like with anything the earlier you can treat a side effect, disorder, disease, the better the success rate.

A final use of this potent AI is pre contest preparation to achieve a maximum level of dryness. Higher estrogen levels can lead to excess water retention and bloating and obviously that’s not going to look good in front of contest judges. Other AI’s can be utilized here as well but with the power of letro it is the clear cut favorite to lower estrogen levels to where little to zero water retention is present. This ultimately will give the user an extremely dry look given their body fat is in a low enough range.

Dosing

On cycle: .25mg - .50mg everyday

This is a general starting dose for those who decide to use Letro as their AI during an anabolic steroid cycle. This is generally for more experienced users who know their body extremely well. For less experienced users aromasin or arimidex is a much safer option.

Gyno Treatment:  2mg – 2.5mg everyday

This is no doubt an extreme dose and will rapidly decrease estrogen levels in the body. Once the gyno symptoms begin to subside it is wise to taper down the letro dosage and resume usage of your current AI.

Precontest:  .50mg – 2mg everyday

There is a lot of variance here and will come down to the individual’s knowledge, experience, and numerous other factors. Letro is often used for the last few weeks before getting on stage and adjusted accordingly to the user’s personal needs.

Side Effects

• Loss of libido/energy
• Bone/joint discomfort
• Hot flashes/headaches
• Nausea
• Numbness or stiffness of extremities
• Abnormal breathing
• Chills and flu like symptoms
• Depression and mood changes
• Negative impact on blood lipids

Additional Facts

Letrozole has a half-life of roughly 48 hours and steady blood plasma levels can be obtained in 2-6 weeks dose depending. Letro also has the ability to raise luteinizing hormone (LH) and follicle-stimulating hormone (FSH) via the negative feedback loop therefore increasing testosterone levels. However a SERM is still superior in this aspect because Letro is still in the class of aromatize inhibitors.

As a final note letrozole is not ideal for the novice user on an anabolic steroid cycle. Its ability to dramatically reduce estrogen levels rapidly can cause more harm than good for the average user. Therefore, it’s primarily recommend for the reasons previously mentioned and with caution. Ultimately, letro does have its place in the anabolic world but only in certain circumstances; the use of either aromasin or arimidex will certainly suffice as an aromatize inhibitor during an anabolic steroid cycle.

By: MikeSnow