Aromasin Side Effects


Throughout this profile, it has been clearly stated that the use of Aromasin (or any aromatase inhibitor) should be for the purpose of Estrogen control rather than Estrogen elimination. The reduction of Estrogen in the body can cause negative changes and problems for the body, especially when aromatase inhibitors are utilized and Estrogen is suppressed long-term. Aromasin side effects are generally manageable and are for the most part very different for males rather than females utilizing it, as it has been previously demonstrated in this profile that Aromasin will impact females in a more significant manner than in males due to different endocrine physiology. This is often the case with all aromatase inhibitors, where the reduction in serum Estrogen levels in females is normally always far greater and fat more significant than in males.

Side Effects Associated With Estrogen Reduction

Nearly all Aromasin side effects are resultant of its effect on the body in reduction of total circulating Estrogen levels as a result of the inhibition of the aromatase enzyme. The following are all of the major potential Aromasin side effects associated with Estrogen reduction.

Joint and bone pain: The fact is that Estrogen is an important hormone in the promotion and retention of bone mineral content, and therefore the promotion of increased bone strengthening. This is why post-menopausal females exhibit increased likelihood of developing osteoporosis due to the natural decline in Estrogen levels with age. Therefore, the reduction in bone strength over time is a characteristic of all aromatase inhibitors, as they all serve to lower total serum levels of Estrogen. However, Aromasin in particular has actually demonstrated in the short term to actually strengthen bone and prevent bone while the use of Arimidex and Letrozole has demonstrated severe reductions in bone strength in the same study[1]. At the same time, long term use among breast cancer patients has demonstrated reduction in bone strength over time. Short term use should present no issues in regards to bone strength and might in fact be beneficial with Aromasin; however, many male users will report increased bone and joint pain when Estrogen is reduced far below normal physiological levels due to Aromasin use. This bone and joint pain will always subside following the cessation of Aromasin (or if Aromasin doses are adjusted as such to allow Estrogen levels to return to normal physiological levels).

Fatigue: A commonly reported Aromasin side effect that is just as common as the issue of bone and joint pain in anabolic steroid users that reduce their Estrogen levels too low, persistent fatigue is also a common problem. This, as previously mentioned, is once again the result of Estrogen levels dropping too low. Estrogen is well known for playing a key role in the proper functioning of the CNS (Central Nervous System), and the reduction of Estrogen (with any aromatase inhibitor) below normal physiological levels can and does result in chronic fatigue that can only be properly remedied by allowing circulating Estrogen levels to return to normal.

Negative effects on cholesterol: This is a side effect common of any and all aromatase inhibitors or any substances that reduce total circulating Estrogen levels in the body. Aromasin side effects are no exception to this. As previously outlined in this profile, Aromasin has exhibited in most studies to impact cholesterol levels negatively to a far less severe degree than all other aromatase inhibitors, but this side effect nevertheless still exists with Aromasin. The fact that it Aromasin exhibits a lesser effect on blood lipid profiles should be reason enough to utilize Aromasin over any of the other aromatase inhibitors.

But this side effect is also the reason why this profile has emphasized the control of Estrogen levels rather than the total elimination of them, and it is important to understand how this mechanism operates. Estrogen is known to play a very important role through its activity in the liver in generating favorable cholesterol levels (increases in HDL, the good cholesterol, and reductions in LDL, the bad cholesterol). When Estrogen levels are reduced below normal physiological levels, cholesterol changes take turns for the worse where HDL (good) cholesterol decreases and LDL (bad) cholesterol increases, creating an increased risk for CVD (Cardiovascular Diseases).

Studies have been conducted whereby 300mg weekly of Testosterone Enanthate was administered for a 20 week period without the use of an aromatase inhibitor which resulted in a 13% reduction of HDL cholesterol, however, when Testosterone doses were raised to 600mg weekly, reduction of HDL cholesterol had proceeded even further to 21%[2].

Therefore, the examined data exhibits a very evident increase in Estrogen via aromatization and liver metabolism which actually helps to offset the negative cholesterol changes from the use of supraphysiological amounts of anabolic steroids. This makes sense, considering Estrogen itself is known to promote positive impacts on cholesterol levels. Therefore, the use of an aromatase inhibitor and its impact on cholesterol profiles should always be remembered when any user is considering the addition of an aromatase inhibitor during a cycle or even for PCT. It is advisable to instead use minimal doses of an aromatase inhibitor while on a cycle for the purpose of Estrogen control rather than total Estrogen level elimination. The idea in such a case is to keep Estrogen levels within normal ranges and not allow them to skyrocket as a result of aromatization, but at the same time prevent them from dropping to near zero from the use of full doses of an aromatase inhibitor.

Androgenic Side Effects

Because Aromasin is a steroidal aromatase inhibitor – a characteristic that neither of the two other major aromatase inhibitors possesses – it does exhibit androgenic activity in the body as evidenced by various studies as well as anecdotal reports by anabolic steroid users. This might even be a beneficial effect for individuals looking to use Aromasin during PCT, which is a period where aggression and drive is often times at an all-time low. As noted by two studies, Arimidex and Letrozole have no androgenic, progestrogenic, or estrogenic effects (such as weight gain, acne, or hypertrichosis), but Aromasin exhibits weak androgenic properties, and its use at higher doses has been associated with steroidal-like side effects such as minor lean mass gain and acne[3] [4]. These effects are normally seen with Aromasin doses of 25mg or higher.

In addition, Aromasin’s metabolite 17-hydroexemestane is a much more potent androgen as well, and also serves to further enhance the androgenic effects of aromasin[5]. It must be understood that Aromasin’s androgenic effect is very minimal at best, but might still present itself in minor levels (tiny bouts of acne, etc.) although individuals that are very sensitive to androgenic side effects should be aware of this. Normally the androgenic effects resultant of Aromasin side effects should not be an issue.

Androgenic side effects can include: increased sebum secretion (oily skin), increased bouts of acne (linked to increased sebum secretion), bodily and facial hair growth, benign prostatic hypertrophy (BPH), and the increased risk of triggering Male Pattern Baldness (MPB) in individuals that possess the genetic trait required for the condition to manifest itself.



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, Shangle Qi, Angela M. Cheung, Haiqing Hu, Maria Mendes, and Kenneth P. H. Pritzker. Clin Cancer Res 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] The minimal effective exemestane dose 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 postmenopausal breast cancer. Michaud L. B., Buzdar A. U. Drug Saf., 21: 297-309, 1999.

[5] Exemestane’s 17-hydroxylated metabolite exerts biological effects as an androgen. Eric A. Ariazi, Andrei Leitão, Tudor I. Oprea, Bin Chen, Teresa Louis, Anne Marie Bertucci, Catherine G.N. Sharma, Shaun D. Gill, Helen R. Kim, Heather A. Shupp, Jennifer R. Pyle, Alexis Madrack, Anne L. Donato, Dong Cheng, James R. Paige and V. Craig Jordan. Mol Cancer Ther November 2007 6; 2817