What is Anastrozole?

The function of anastrozole is to decrease the amount of estradiol (E2) the body makes.

Estradiol is the most potent form of estrogen, and it is synthesized from testosterone through the enzymatic activity of aromatase. Aromatase activity has been found in fat, hair, bone, muscle, vascular and breast tissue. Anastrozole is a nonsteroidal aromatase inhibitor. It reversibly binds to the aromatase enzyme and, through competitive inhibition, blocks the conversion of testosterone to estradiol, especially in the peripheral (extragonadal) tissues.

Anastrozole is only available in the U.S. via traditional or compounding prescriptions.

Who May Benefit From Anastrozole?

Although anastrozole has been used primarily in treating estrogen-dependent breast cancer in postmenopausal women, it can also support the right balance of hormones in both men and women.
Breast cancer survivors or at-risk postmenopausal women

Studies have shown that testosterone, in combination with a low dose of anastrozole, helps relieve menopausal symptoms when estrogen therapy is contraindicated — for breast cancer survivors or women at high risk for the disease.

Women with excess estrogen

Excess estrogen or low levels of other hormones such as progesterone or testosterone can upset hormonal balance. In some patients, finding that balance during the initial stages of hormone replacement therapy can take time. Since every patient’s body reacts differently, it is important to adjust hormone therapy to the individual. Anastrozole can be a useful adjunct. It may relieve symptoms associated with high estrogen levels, such as weight gain, bloating, cold hands, or mood swings. It also may help lower the risks of health conditions related to high estrogen, including endometrial and breast cancers.

Men with low testosterone levels or undergoing testosterone replacement therapy

Anastrozole may help increase testosterone levels in males by blocking its conversion into estrogen. It has been studied as an alternative method of androgen replacement therapy. In men, as well as women, hormone balance appears to be more important than individual hormone levels. In men specifically, the serum T/E2 (testosterone/estradiol) ratio needs to be optimal. If too much testosterone is being converted into estradiol in the body, this can have negative effects on the prostate, cholesterol levels, cardiovascular health, fertility, as well as physical effects such as breast enlargement. Treatment with anastrozole can lower estradiol levels to help resolve side effects and lower these health risks.

Men with fertility or sexual functioning issues

Estrogen, particularly estradiol, is vital to male fertility – specifically to sperm count. Low sperm count and infertility can occur when estrogen levels are too low or too high. Estradiol also affects libido and erectile function, partly due to bountiful estrogen receptors in a man’s sexual organs and brain. When estrogen levels are high, there may be a greater chance of erectile dysfunction. Anastrozole may help with any male sexual issues related to high estrogen levels.

How Belmar Can Help

If you’re a clinician interested in prescribing compound medications to your patients, contact us for information on how to get started and to access all of our clinical resources. If you are new to compounding, you may find our page on How to Write a Compounding Prescription helpful. You can also visit our Treatment Options page to find a formulary and learn more about all the medication solutions available from Belmar.