This entire profile explicitly states that the use of Aromasin (or any aromatase inhibitor) should aim for estrogen modulation, not estrogen elimination.
A reduction in bodily estrogen can cause negative changes and issues for the body, especially when estrogen is suppressed for prolonged periods using aromatase inhibitors.
Aromasin side effects are generally manageable and manifest very differently, mostly in men rather than women, as it was previously demonstrated in this profile that Aromasin affects women more significantly than men due to differing endocrine physiology.
This is a phenomenon seen with all aromatase inhibitors, as the reduction in serum estrogen levels is generally much greater in women and they often have a higher body fat percentage.
Side Effects Associated with Estrogen Reduction
Nearly all Aromasin side effects are a consequence of the reduction in total circulating estrogen levels in the body due to the inhibition of the aromatase enzyme.
The following are the main potential Aromasin side effects associated with reduced estrogen.
Joint and Bone Pain: In fact, estrogen is a crucial hormone for promoting and maintaining bone mineral content, thereby facilitating bone strengthening.
This is why post-menopausal women are more likely to develop osteoporosis as they age, due to the natural decline in their estrogen levels.
Therefore, a decrease in bone strength over time is characteristic of all aromatase inhibitors, as all aromatase inhibitors function to lower total serum estrogen levels.
However, notably, Aromasin has actually been shown to strengthen bone and prevent fractures in the short term, whereas Arimidex and Letrozole were found in the same study to significantly reduce bone strength [1].
Concurrently, it has been observed that bone strength decreases over time in breast cancer patients using it long-term.
Short-term use does not pose problems for bone strength and may even be beneficial with Aromasin, but many male users report increased bone and joint pain when estrogen drops significantly below normal physiological levels due to Aromasin use.
This bone and joint pain always subsides when Aromasin use is discontinued or the dosage is adjusted to allow estrogen levels to recover to normal physiological levels.
Fatigue: Similar to the bone and joint pain issues reported by anabolic steroid users who suppress their estrogen levels too low, persistent fatigue is another commonly reported Aromasin side effect.
This is, as mentioned earlier, due to estrogen levels being driven too low.
Estrogen is well-known to play a vital role in the proper functioning of the Central Nervous System (CNS), and a reduction of estrogen below normal physiological levels via aromatase inhibitors can cause chronic fatigue, a symptom that can only be properly remedied by restoring circulating estrogen levels to normal.
Negative Impact on Cholesterol: This is a side effect common to all aromatase inhibitors, or any substance that reduces the body’s total circulating estrogen levels.
Aromasin side effects are no exception.
As explained earlier in this profile, Aromasin has been shown in most studies to negatively impact cholesterol levels to a far less severe degree than all other aromatase inhibitors; nevertheless, this side effect still exists with Aromasin.
The fact that Aromasin has a lesser impact on blood lipid profiles is sufficient reason to use it over other aromatase inhibitors.
However, this side effect is also why the emphasis has been placed on modulating estrogen rather than eliminating it entirely, and understanding how this mechanism works is important.
Estrogen is known to play a very important role in the liver, acting to produce favorable cholesterol levels (increasing good cholesterol, HDL, and decreasing bad cholesterol, LDL).
When estrogen levels fall below normal physiological levels, a shift in cholesterol occurs, resulting in decreased good cholesterol (HDL) and increased bad cholesterol (LDL), thereby increasing the risk of Cardiovascular Disease (CVD).
One study showed that using testosterone enanthate at 300mg per week for 20 weeks without an aromatase inhibitor resulted in a 13% decrease in HDL cholesterol, and when the testosterone dose was increased to 600mg per week, the HDL cholesterol reduction progressed further to 21% [2].
Thus, the data investigated shows a very clear increase in estrogen via aromatization and hepatic metabolism, which actually helps counteract the negative cholesterol changes induced by the use of supraphysiological amounts of anabolic steroids.
This makes perfect sense, considering that estrogen itself is known to positively influence cholesterol levels.
Therefore, the use of aromatase inhibitors and their impact on cholesterol profiles is something every user considering adding an aromatase inhibitor during a cycle or for PCT must always keep in mind.
It is advisable to use the minimum effective dose of an aromatase inhibitor during a cycle with the goal of estrogen modulation rather than total estrogen elimination.
The idea in this case is to keep estrogen levels within the normal range, preventing them from spiking due to aromatization, while simultaneously preventing them from crashing to near-zero levels due to full-dose aromatase inhibitor use.
Androgenic Side Effects
Because Aromasin is a steroidal aromatase inhibitor, which the other two primary aromatase inhibitors are not, it exhibits androgenic activity in the body, as demonstrated in various studies and anecdotal reports from anabolic steroid users.
This can also be a beneficial effect for those wishing to use Aromasin during the PCT period, when aggression and drive are typically at their lowest.
Two studies state that while Arimidex and Letrozole have no androgenic, progestogenic, or estrogenic effects (weight gain, acne, hirsutism, etc.), Aromasin exhibits weak androgenic properties and may cause slight weight gain and steroid-like side effects such as acne at high doses.[3] [4]
These effects are generally seen at Aromasin dosages of 25mg and above.
Furthermore, Aromasin’s metabolite, 17-hydroexemestane, is a much more potent androgen and serves to further enhance the androgenic effects of Aromasin [5].
It must be understood that the androgenic effects of Aromasin are, at best, very mild, but individuals highly sensitive to androgenic side effects might experience them at a minor level (slight acne, etc.).
Generally, the androgenic effects from Aromasin side effects are not an issue.
Androgenic side effects can include increased sebum production (oily skin), increased acne incidence (linked to increased sebum production), body and facial hair growth, Benign Prostatic Hyperplasia (BPH), and an increased risk of triggering Male Pattern Baldness (MPB) in individuals possessing the necessary genetic predisposition for it to occur.
Medical References
[1] Effects of the steroidal aromatase inhibitor exemestane and the nonsteroidal aromatase inhibitor letrozole on bone and lipid metabolism in ovariectomized rats. Paul E. Goss1, Shangli Chi, Angela M. Cheung, Haiqing Hu, Maria Mendes, Kenneth P. H. Pritzker. September 1, 2004, 10;5717.
[2] Testosterone dose-response relationships in healthy young men. Bhasin S, Woodhouse L. et al. Am J Physiol Endocrinol Metab 281:E1172-81, 2001
[3] Minimal effective dose of exemestane for endocrine activity in advanced breast cancer. Bajetta E., Zilembo N., Noberasco C., Martinetti A., Mariani L., Ferrari L., Buzzoni R., Greco M., Bartoli C., Spagnoli I., Danesini G. M., Artale S., Paolini J. Eur. J. Cancer, 33: 587-591, 1997.
[4] Risks and benefits of aromatase inhibitors in post-menopausal breast cancer. Michaud L. B., Buzdar A. U. Drug Saf., 21: 297-309, 1999.
[5] The 17-hydroxylated metabolite of exemestane exerts biological effects as an androgen. Evrard A. Ariazi, Andrei Leitão, Tudor I. Oprea, Vin Chen, Teresa Lewis, Ann Marie Bertucci, Catherine G.N. Sharma, Sean D. Gill, Helen R. Kim, Heather A. Shupp, Jennifer R. File, Alexis Madrack, Ann L. Donato, Dong Cheng, James R Page and V. Craig Jordan. Mol Cancer Ther November 6 2007; 2817
