Exemestane 25 mg (Aromasin) belongs to a category and class of drugs known as aromatase inhibitors (AIs). Aromatase inhibitors fall under a broader classification of drugs called anti-estrogens. The other major subcategory within anti-estrogens is selective estrogen receptor modulators (SERMs), such as Nolvadex (Tamoxifen) and Clomid (Clomiphene). Together, aromatase inhibitors and SERMs make up the anti-estrogen class of compounds.
Although both AIs and SERMs are used for estrogen control, they differ significantly in mechanism of action and overall effect on estrogen levels.
Common Misunderstanding About SERMs and Estrogen
For many years, a widespread misunderstanding has persisted within the anabolic steroid–using and bodybuilding community. While clarity has improved over the past 10–15 years, the myth still appears frequently: SERMs do not lower estrogen levels.
This misconception likely stems from the fact that SERMs are often referred to as “estrogen blockers.” Many individuals mistakenly interpret this to mean that SERMs eliminate estrogen from the body. In reality, this could not be further from the truth.
SERMs do not reduce circulating estrogen levels in the bloodstream. Instead, they work by blocking estrogen activity at specific receptor sites, most notably in breast tissue. They do this by occupying estrogen receptors, preventing estrogen itself from binding and exerting its effects in those tissues.
At the same time, SERMs may act as estrogen agonists in other tissues, such as the liver (as seen with Nolvadex). This tissue-specific behavior is what defines them as “selective” estrogen receptor modulators.
How Aromatase Inhibitors Work
Unlike SERMs, aromatase inhibitors directly reduce estrogen levels by targeting the aromatase enzyme. Aromatase is responsible for converting androgens (such as testosterone) into estrogen through a process known as aromatization.
By binding to and disabling this enzyme, aromatase inhibitors effectively prevent estrogen production at its source, leading to significantly lower estrogen levels in blood plasma.
Exemestane 25 mg (Aromasin): A Suicidal Aromatase Inhibitor
Exemestane 25 mg (Aromasin) is a highly potent, steroidal aromatase inhibitor of the suicidal (irreversible) type. Clinical data included in Aromasin’s prescription packaging demonstrates its ability to reduce estrogen levels by up to 85%, as shown in studies involving breast cancer patients.
Suicidal aromatase inhibitors like Exemestane work by permanently binding to and disabling the aromatase enzyme. Once bound, the enzyme is rendered inactive for the remainder of its lifespan. While the body will eventually produce new aromatase enzymes, the enzymes already bound to Exemestane are permanently deactivated.
This unique property eliminates the risk of estrogen rebound, a phenomenon commonly associated with non-suicidal aromatase inhibitors.
Exemestane vs. Non-Suicidal Aromatase Inhibitors
Other popular aromatase inhibitors, such as Arimidex (Anastrozole) and Letrozole, are non-suicidal. These compounds bind to the aromatase enzyme only temporarily. Once they unbind and are metabolized, the enzyme becomes active again.
If non-suicidal aromatase inhibitors are discontinued abruptly, previously inhibited aromatase enzymes can rapidly resume estrogen production, often resulting in a sharp estrogen rebound.
This rebound effect does not occur with Exemestane, making it a preferred option for individuals seeking stable, long-term estrogen control.
Reviews
There are no reviews yet.