SERM vs AI – Selective estrogen receptor modulator vs aromatase inhibitor

SERM and AI are Bodybuilders used to reduce and prevent estrogen-related adverse reactions in AAS cycle.

SERM is a modulator of estrogen receptors, including tamoxifen and clomiphene.

AI is an aromatase inhibitor, including exemestane and Arimidex.

AI is divided into two types, one is an irreversible steroid inhibitor, such as exemestane, that forms a permanent binding to the aromatase complex. Another NSAID inhibitor, such as anastrozole and letrozole, inhibits aromatase through reversible competition.

The key difference between SERM vs AI is what they do to the body and how they affect oestrogen. SERM works by blocking the effects of estrogen by binding to estrogen receptors in certain body parts. SERM acts on estrogen receptors, not estrogen itself, and does not reduce serum estrogen levels.

AI works by reducing estrogen levels in the body. AI works by blocking the action of aromatase in the body, preventing the conversion of testosterone by aromatase to estrogen, thereby reducing estrogen levels in the body, increasing testosterone levels, and reducing the incidence of male atrial development.

In short, SERM prevents estrogen from acting on certain parts of the body, and AI prevents the body from synthesizing estrogen, both of which work in completely different ways.

SERM is highly effective in controlling a large number of AAS-induced estrogenic side effects. Serms like tamoxifen and Clomid help control gynecomastia because they are designed to prevent the development of estrogen receptors in breast tissue.

AI is good for water retention, while SERM is not. Therefore, the bodybuilder will choose AI for water retention issues. However, when the bodybuilder faces gynecomastia, it will need to choose SERM.

When to chosseSERM?

During PCT, SERM is basically chosen over AI because PCT basically addresses the problem of endogenous testosterone inhibition. AI does not address testosterone suppression, SERM does.

When to choose AI?

SARM does not aromatize, so SARM cycle does not require AI.AAS do aromatize, so AAS cycle usually requires AI. But some AAS that do not aromatize, such as DHT derivatives, do not require AI.

It can be seen from the above that the action modes of SERM vs AI are different. AI is mostly used in AAS cycle, while SERM is mostly used in PCT cycle.