Aromatase Inhibitors and testosterone replacement therapy

Testosterone replacement therapy is a lot more than just testosterone. We must consider the systemic effect of endogenous replacement testosterone.

Estradiol is the most potent of the three estrogens – estrone, estradiol and estriol. For this reason, it is typically the only one tested in blood and also because it is difficult to get a reliable reading and adds to the lab costs.

Although estrogen is often thought of as a female hormone, it is also important  in men. Estradiol on the low range can manifest as the following symptoms:

  • Depression
  • Fatigue
  • Joint Pain
  • Limited erection sensitivity

Keeping estrogen as low as possible is not an optimal strategy. Actually, it’s a terrible one! Just like in women, estrogen helps prevent atherosclerosis, dementia and osteoporosis in men. Like all hormones, the goldilocks rule applies – not too much, not too little.

On the flipside, estrogen that is too high in men can result in the following symptoms:

  • Water retention
  • Excessive sweating
  • Insomnia
  • Hot flashes / night sweats
  • Bloating
  • Fatigue
Testosterone Replacement Therapy

When embarking on a testosterone replacement therapy program, it is important to have all hormones tested, including Estrogen (Estradiol). If your doctor does not test your estrogen, then you need to find another physician!

Aromatase Inhibitors

Testosterone and other precursors such as DHEA (androgens) can convert to estrogen in a process called aromatization. Aromatase inhibitors (AI) are a class of drugs that block the conversion of testosterone to estrogen and are commonly used in the treatment of breast cancer in post-menopausal women with tamoxifen as the popular drug of choice.

An off-label use of AIs is to prevent the conversion of testosterone to estrogen in men on testosterone replacement therapy (TRT). The most commonly prescribed AI is arimidex – more commonly known as anastrazole.

Are Aromatase Inhibitors Necessary?

AIs are not absolutely necessary while in TRT and recommendation should be on a case by case basis. If baseline estradiol is low and sex-hormone binding globulin high-normal then an acceptable strategy may be finding the testosterone and/or HCG dosage that results in an optimal increase to estradiol levels (through aromatization). Taking an AI in the previous example would tank the estrogen levels even lower and leave you feeling miserable.

On the flipside, if baseline estradiol is elevated then preventing the conversion of testosterone/HCG to estrogen would be a wise decision.

Alternatives to Aromatase Inhibitors

As with most drugs, there are several alternatives to taking a prescriptive AI:

  • Zinc supplementation with copper in a 10:1 ratio
  • More frequent testosterone injections, at a lower dose
  • Injecting testosterone subcutaneous (SubQ) instead of intramuscular (IM).
The Importance of Communication

Above all, it is extremely important to communicate with your health care professional regarding your program. Finding an optimal balance is a process that takes time. Estradiol is the most difficult hormone to balance while on a testosterone replacement therapy.

To discuss your hormone replacement case  with one of our qualified health care professionals, contact us today in Miami at 305.448.2600

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