SERMs and AIs – know the difference

Today, we decided to touch on another topic related to estrogen management on cycle that is biased with even more misconceptions and misunderstanding that the previous one. We are talking here about confusing SERMs (selective estrogen receptor modulators) and AIs (aromatase inhibitors) or even not differentiating them at all. Both scenarios can be a source of unpleasant experience, so here’s what you need to know:

What are SERMS?

SERMs are products that act selectively on estrogen receptor. A characteristic that distinguishes these substances from pure ER agonists and antagonists (that is, full agonists and silent antagonists) is that their action is different in various tissues, thereby granting the possibility to selectively inhibit or stimulate estrogen-like action in various tissues.
How are they useful in reduction on estrogen related side effects experienced on cycle?
They are useful in situations, where for some particular reason, you don’t want to reduce your overall estrogen level and instead want only to reduce some of its side effects, that namely are: gynecomastia, excessive fluid retention, oily skin/hair. This approach would be especially true and reasonable in cases where your cycle is based on low dosage of testosterone, or you are running some of its oral derivatives (like dbol, anavar etc.) and you don’t want to ruin your estrogen levels with some potent AIs.

What are the AIs then?

AIs – aromatase inhibitors – are class of products used in treatment of excessive estrogen level, mainly in women struggling with breast cancer, but also with men struggling with gynecomastia. Mechanism of action of AIs is based on inhibition of aromatase – enzyme that catalyzes a key aromatization step in the synthesis of estrogen from testosterone.
And how are they useful, and what differentiate them from SERMs?
AIs will aid in removing overall estrogen level – what is desirable in cases when you run moderate to higher doses – as the ‘amount’ of tissue affected by estrogen will be more noticeable for you, and the easiest and probably the only effective way of dealing with it will be to reduce estrogen level itself. This is mainly because in order to deal with that amount of estrogen in your organism, SERMs will simply not be sufficient enough, not mentioning the cost of it.
Short remainder of which products are SERMs and AIs.

SERMs are:

  • Nolvadex (tamoxifene)
  • Evista (raloxifene)
  • Fareston (toremifene)

AIs are:

  • Femara (letrozole)
  • Aromasin (exemestane)