What’s the Difference Between an Aromatase Inhibitor and Selective Estrogen Receptor Modulator?

If you’re serious about weight training and/or bodybuilding, and hang around others who are, you’ve probably at one time or another–either knowingly or unknowingly–run into someone who’s used steroids.

Maybe you’ve thought about using them yourself, or maybe you already have.

I don’t think there’s anything wrong with using steroids… as long as you understand how to use them and use them smartly.

Like anything else, moderation is the key. Drink a few beers ever now and then and you’ll never have any problems. Pound a 12-pack every night and it’s going to cause problems.

But steroids are bad, you say?

Let me see if I can get you to think about it differently.

  • Women take the “pill” to artificially manipulate the body’s hormones to prevent pregnancy
  • Doctors give women with breast cancer drugs to artificially manipulate the body’s hormones to prevent and limit cancer progression
  • Doctors give patients with AIDS, cancer, and other muscle wasting diseases steroids to help them retain muscle mass
  • Bodybuilders and weight lifter use steroids to artificially manipulate the body’s hormones to promote muscle synthesis

Why are the first three OK but the last one not? People do all sorts of things to alter their appearance, why shouldn’t steroids be one of them?

However! And this is a big however….

If you’re an average person who wants to get stronger, be healthier, and look better, you don’t need or nor should you use steroids. The potential complications from uneducated steroid use aren’t worth it.

But if you’re a fitness model or bodybuilder who’s ability to make a living depends on your physical appearance, have at it. And, even then, you should be pushing your natural limits first, and that means years of training.

Also, since steroids affect how the body produces and regulates hormones, no one who is not yet mature should use steroids. If you’re not at least 25 years old, keep eating and keep lifting, and put the thought of using steroids out of your mind.

Taking Steroids

So maybe you’ve decided to consider steroids as a way to enhance your weight training efforts. Maybe you’ve done a cycle or two and are considering another more intense cycle with higher dosages.

If that’s you, then know steroids can have side effects.

Using Aromatase Inhibitors (AIs) and Selective Estrogen Receptor Modulators (SERMs) can help reduce or eliminate those side effects. These two compounds are a very important part of anabolic steroid use.

What Do AIs and SERMs Do?

Both AIs and SERMs provide a way to either control the amount of estrogen in your body or how much of that estrogen your body uses.

Controlling estrogen levels and its effects is very important in preventing some significant side effects.

Most anabolic steroids convert to estrogen (as well as testosterone). Your body’s own testosterone can convert to estrogen as well. When you have elevated levels of estrogen, you open yourself up to the following potential side effects:

  • Decreased libido and impotency
  • Bloating and weight gain
  • Gynecomastia (a condition in which men develop female breast tissue)
  • Irritability

Keeping estrogen under control by blocking its synthesis with AIs or preventing the body from using it with SERMs can prevent these side effects.

What Is an Aromatase Inhibitor?

Aromatase is an adrenal enzyme that converts androstenedione and estrone (forms of testosterone) to estrogen. An AI prevents this conversion from happening.

Some steroids are more androgenic. And androgen is any natural or synthetic compound that stimulates or controls the development and maintenance of male characteristics by binding to androgen receptors.

Androgens are in the body, they are converted into estrogen by enzyme known as aromatase.

An aromatase inhibitor (AI) binds to the aromatase enzyme, preventing it from converting androgens into estrogen. So it actually stops the production of estrogen by inhibiting the conversion of testosterone to estrogen.

Arimidex is the most popular AI among steroid users. Letrozole is another option for men who are particularly sensitive to the effects of estrogen or who want to reverse existing gynecomastia.

All right then, an AI prevents estrogen production. But the body, seeing these lower levels, continues to send signals that it needs more estrogen. This cycle can sometimes result in a rebound effect where estrogen levels spike after stopping the AI.

What Is a Selective Estrogen Receptor Modulator?

A selective estrogen receptor modulator (SERM) binds to the estrogen receptor, thus blocking estrogen from being able to bind to it.

So rather than preventing the production of estrogen like an AI, it blocks existing estrogen from being used.

Two of the most popular SERMs are Nolvadex and Clomid.

Chlomid also has some interesting properties when it comes to stimulating the Hypothalamic-Pituitary-Testicular Axis (HPTA). This is (basically) the “system” that monitors and control hormonal balance. In some men, Chlomid has been show to stimulate the HPTA, causing an increase in both testosterone and estrogen.

But that’s a whole other topic.

So a SERM affects the way the body uses estrogen, not how it’s produced, so as far as the body is concerned, there is plenty of estrogen available. This makes a SERM most useful during post-cycle therapy to combat rebounds until hormone levels normalize.

It’s important to understand that men need some estrogen for normal function. Too little estrogen can cause side effects as unpleasant as too much.

That’s why monitoring blood hormone levels while on cycle and during post cycle therapy is so important.

Used smartly and properly, steroids are no more dangerous than any other medication.

Know before you grow!


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