Letrozole Overview & Features

Overview and History of Letrozole

Letrozole (Femara) belongs to a category and class of drugs known as Aromatase Inhibitors (AIs).

Aromatase Inhibitors fall under a much broader class of drugs known as anti-estrogens.

Other subcategories of drugs within the anti-estrogen category are known as Selective Estrogen Receptor Modulators (SERMs), such as Nolvadex and Clomid.

Aromatase Inhibitors and SERMs make up the anti-estrogens.

Aromatase Inhibitors differ significantly from SERMs in their mechanism of action and how they address estrogen control.

The misconception that SERMs like Nolvadex and Clomid work to lower estrogen levels must be addressed before we go any further.

This is a rumor that has recently started to fade in the anabolic steroid-using community, but it still persists.

SERMs work by occupying receptor sites in place of estrogen, thereby blocking estrogen’s actions at those receptor sites and preventing estrogen itself from exerting its effects in breast tissue through receptor site binding.

Conversely, SERMs also act as estrogens at receptor sites in other cells in other areas of the body (for example, in the liver, in the case of Nolvadex).

SERMs do not lower the circulating levels of estrogen in blood plasma.

Aromatase Inhibitors act by binding to and disabling the aromatase enzyme, which is the enzyme responsible for the conversion (or aromatization) of androgens into estrogen, thereby eliminating estrogen production.

Letrozole is a non-steroidal and non-suicidal Aromatase Inhibitor, and it belongs to the third generation of Aromatase Inhibitors.

Letrozole is very similar to Arimidex and is one of the three major Aromatase Inhibitors (Arimidex, Aromasin, and Letrozole).

The difference between Letrozole and the other two major Aromatase Inhibitors is that while it is used in the treatment of post-menopausal female breast cancer patients, it is actually used specifically for estrogen receptor-unknown breast cancers.

This is a breast cancer condition where diagnostic results are unable to determine whether or not estrogen is the cause or is aggravated by it.

Like all other Aromatase Inhibitors, Letrozole is generally used after a first-line treatment (such as Nolvadex) has failed, although under various conditions, Letrozole might be required as a first-line treatment, though this is rare.

Letrozole was developed after Arimidex but before Aromasin, and it is the most potent and powerful of the Aromatase Inhibitors.

Novartis manufactured the drug after it received approval for sale in the US prescription market in 1997, where it is sold under the brand name Femara and a separate brand name, also Femara, in some countries around the world (primarily some European nations).

Like other Aromatase Inhibitors, it is very widespread and common not only in North America but also in regions, countries, and markets worldwide, with over 70 countries carrying Letrozole, and the brand name Femara is estimated to be the most popular and widely used.

Besides its main brand name, Letrozole is also marketed under numerous other generic brands.

Letrozole (Femara), like all Aromatase Inhibitors, naturally gained popularity among anabolic steroid users in the athletic, bodybuilding, and general population.

This is due to Letrozole’s estrogen control and reduction capabilities, which are favored by anabolic steroid users who use aromatizable anabolic steroids (such as Testosterone, Dianabol, Equipoise, etc.) and can effectively control issues resulting from excess estrogen (bloating, blood pressure, gynecomastia, etc.).

Chemical Characteristics of Letrozole

Letrozole (Femara) is a non-steroidal Aromatase Inhibitor.

This means that unlike the steroidal Aromatase Inhibitor Aromasin (Exemestane), it does not possess the characteristic four-ring cycloalkane carbon structure common to all steroids.

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Properties of Letrozole

Studies have shown that Letrozole’s effects on controlling serum estrogen levels are the most potent and effective of the three major Aromatase Inhibitors.

The informational pamphlet included with the medication also states that a standard tablet dose of 2.5mg is effective at lowering blood estrogen levels by an average of 78%.

However, actual clinical data has demonstrated even more effective reductions (it should be remembered that 78% is the determined average).

Studies have shown Letrozole to reduce serum estrogen levels by at least 98% or more.

Because Letrozole is so effective at lowering estrogen levels by inhibiting the aromatase enzyme, it is generally administered only to post-menopausal women or in cases where other first-line breast cancer treatments have failed.

This is a common aspect of all three major Aromatase Inhibitors, as they are all very effective compounds for estrogen reduction, with Letrozole being the most effective among them.

Arimidex and Letrozole are both classified as non-steroidal and non-suicidal Aromatase Inhibitors, which compete with the substrate for binding to the enzyme’s active site.

This is very different from Aromasin (Exemestane), which is a steroidal and suicidal Aromatase Inhibitor that is mechanism-based, mimicking the substrate and being converted by the enzyme into a reactive intermediate that inactivates the aromatase enzyme.

To explain in layman’s terms, this means that Aromasin’s chemical structure resembles the traditional ‘target’ that aromatase binds to (e.g., Testosterone), essentially ‘tricking’ the aromatase enzyme into binding with it, thereby inhibiting/disabling it.

Because the binding strength is so strong, this inhibition of the aromatase enzyme that Aromasin binds to is permanent.

Since Arimidex and Letrozole are non-suicidal Aromatase Inhibitors, they compete with the enzyme’s traditional ‘target’ rather than securing a permanent spot (this is an advantage that Aromasin has over the other two).

Letrozole, like all Aromatase Inhibitors, has also demonstrated the ability to increase endogenous production of LH (Luteinizing Hormone), FSH (Follicle Stimulating Hormone), and consequently, increase Testosterone levels in men, but this will be covered in more detail in the Letrozole dosage section of the profile.

Bodybuilders and athletes using anabolic steroids generally prefer Aromatase Inhibitors like Letrozole, which can eliminate the root cause of rising estrogen levels: aromatase.

By disabling the aromatase enzyme, aromatizable androgens above physiological levels, such as Testosterone, Dianabol, and Deca-Durabolin, are not converted to estrogen, eliminating the risk of estrogen-related side effects.

Letrozole Side Effects

If you’re wondering about the possible side effects of Letrozole, this detailed guide will help.

Letrozole belongs to a class of drugs called Aromatase Inhibitors.

Its side effects are similar to those of another popular AI (Aromatase Inhibitor) known as Arimidex.

Weakness and fatigue are the two main side effects most frequently experienced by Letrozole users.

This medication is used to treat infertility.

It is also popular with bodybuilders and those who use anabolic steroids to build muscle.

Letrozole has the ability to reduce certain side effects associated with anabolic steroids.

For example, men who want to avoid feminization side effects like gynecomastia may find this drug effective.

This medication helps prevent feminization issues in steroid users by inhibiting estrogen production.

Anabolic steroid users who use Letrozole also tend to avoid Letrozole side effects, as long as the estrogen suppression isn’t too severe.

However, there are exceptions.

For instance, a bodybuilder undergoing a tough pre-contest preparation may be on a strict diet and training with high intensity.

This type of bodybuilder may be more susceptible to the side effects of Letrozole.

Since a strict diet and hard training tend to cause fatigue and weakness, it can sometimes be difficult for a bodybuilder to know if the side effects are from Letrozole, their current lifestyle, or both.

Other possible side effects associated with this medication include hot flashes, headaches, depression, and joint pain.

Additionally, this drug sometimes reduces the mineral content inside bones.

This can put Letrozole users at a higher risk of developing osteoporosis.

However, since many steroids increase the mineral content inside bones, anabolic steroid users who also use Letrozole tend to have a lower risk.

One of the anabolic steroids that increases bone mineral content is Nandrolone.

Some people react negatively to Letrozole, while others do not.

Everyone’s body is different, and reactions to medications vary from person to person.

This should be kept in mind when deciding whether or not to use Letrozole.

If you take a medication and have a bad reaction, you should know that there are other drugs that serve the same purpose.

An alternative medication may be better tolerated by your body.

The last side effect associated with Letrozole is cholesterol issues.

Specifically, the use of the drug can cause a decrease in HDL cholesterol levels.

When this AI drug is used alone, it does not appear to have a statistically significant impact.

However, when used with anabolic steroids, it can cause cholesterol problems.

Many anabolic steroids can negatively affect cholesterol levels.

When used with anabolic steroids, there is a risk of worsening cholesterol problems.

Clinical research statistics show that when therapeutic doses of testosterone are administered, there is little negative impact.

However, when Testosterone and Letrozole are used together, the combination of the two drugs can suppress HDL cholesterol levels by up to a quarter.

This is a fairly significant suppression effect and should be noted.

When Testosterone is administered at “supraphysiological” levels, a minimal level of HDL suppression can be expected.

If the same dose is used with an Aromatase Inhibitor, HDL suppression at the level of 20% (or more) can occur.

Because of the risk of cholesterol-related side effects, especially when using anabolic steroids concurrently, it is important for anyone taking Letrozole to maintain a lifestyle that promotes healthy cholesterol levels.

For example, opting for a diet that minimizes saturated fats and simple sugars can be helpful.

Additionally, adding more omega fatty acids to your daily diet is also beneficial.

Omega-3 fatty acids can be consumed through supplements or through diet.

Taking supplements may be a more convenient way to get the required amount.

Furthermore, some people taking Letrozole report benefits from taking cholesterol antioxidant supplements.

Also, if you plan to use or are already using Letrozole, you should add cardiovascular exercise to your lifestyle.

Because cholesterol issues are a risk, some anabolic steroid users prefer to take SERMs to combat estrogenic side effects.

While SERMs don’t always solve every problem, it is true that they work for many people.

If an Aromatase Inhibitor is necessary, taking about 10 milligrams of Nolvadex daily along with the AI may be sufficient to maintain optimal cholesterol levels.

SERMs promote normal cholesterol levels.

Letrozole Administration and Usage

Most women who are prescribed Letrozole for breast cancer treatment take 2.5 milligrams per day.

This dosage is very potent and is typically taken until breast cancer symptoms disappear.

When a breast cancer patient goes into remission, they are switched from Letrozole to Nolvadex to prevent a recurrence of the same disease.

At this dosage level, the likelihood of weakness and fatigue is quite high.

Anabolic steroid users typically take a lower dose, such as half to one milligram of the drug per day.

Men experiencing “man boobs” (gynecomastia) related to anabolic steroid use may take a higher dose, such as 2.5 milligrams per day.

However, taking such a high dose increases the risk of side effects.

This drug is sold under the brand name Femara.

Femara is sold worldwide in convenient tablet form.

A prescription is required for purchase.

However, Letrozole can be sold by research chemical labs through the black market, and it can also be sold by anabolic steroid suppliers (underground labs).

There are many Aromatase Inhibitors on the market, with the most popular and well-known being Arimidex.

That said, many people prefer Letrozole.

Sometimes people experiment with both at different times to find what works best for them.

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Letrozole (aka Femara)