Does Low Testosterone Affect Estrogen Levels?

Written by Ben Bunting: BA, PGCert. (Sport & Exercise Nutrition) // British Army Physical Training Instructor // S&C Coach.

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In the quest for more muscle growth you may want to know more about the effects of testosterone on the body and its relationship with estrogen.  

In this article we cover the following points:

• Hormones
• Testosterone
• Estrogen
• The relationship between testosterone and estrogen
• Conclusion

Hormones 

 The endocrine system is a highly developed system consisting of various hormones that interplay to carry out certain effects.

Hormones are chemical messengers of our body that help regulate various bodily functions and maintain the body’s homeostasis.

Common effects of different hormones include physical and mental growth, puberty, and the development of the cognitive function. 

Testosterone (T) and estrogen are two of the body’s crucial hormones. Most people know these hormones as male and female sex hormones, respectively.

However, it should be noted that these hormones are present in both males and females. Testosterone is the main sexual hormone present in males and females, on the other hand, house estrogen. 

Testosterone (T)

Testosterone, an androgen, is an anabolic hormone. As mentioned above, it is found in both men and women, the former having higher quantities of it.

Testosterone is crucial for the normal development of several organ systems including:

• Development of tests (in males)
• Sperm production
• Muscle and bone development
• Cognitive (brain) development
• Sexual drive (both males and females)
• Distribution of body fat
• Hair growth, especially facial hair in men
• Stimulating the production of red blood cells^1–3 

Women usually have low testosterone levels and high testosterone levels often lead to certain problems like acne, joint pain and other issues.

Normal testosterone levels in women support bone growth, maintain sexual drive, and promote cognitive health. Unfortunately, above-normal levels  are associated with conditions like:

• Acne
• Enlargement of the clitoris
• Increase muscle rigidity and muscle mass
• Polycystic ovarian syndrome (PCOS)
• Infertility
• Baldness 

Estrogen

Estrogen, the infamous female hormone, has female-specific effects, and just like testosterone, it is present in both males and females.

Estrogen stimulates important changes in the female body and, to some extent, has physiological functions in males too. In females, estrogen promotes:

• Breast tissue growth
• Uterine tissue growth
• Bone development and protective effects
• Softening of the skin (also creates more vascularization in the skin leading to redness of the skin)
• Widening of the pelvis (during pregnancy)
• Sexual development of females and normal sexual function
• Increased body fat² 

In males, estrogen is also been found to have an essential role in the proper development and sustainability of the male reproductive system.

While it is difficult to suggest the exact role of estrogen, an optimum balance between estrogen, testosterone, and aromatase in the testes, penis, and brain is required for normal sexual development and performance⁴.

Higher than normal estrogen levels in males might cause:

• Gynecomastia (enlarged breast in males)
• Underdeveloped sexual characteristics
• Small genital size
• Decreased muscle growth (catabolism) and increased body fat^1,2 

Relationship between Testosterone and Estrogen

Like many other hormones, testosterone and estrogen have been correlated to some extent.

Rise and fall in one of the hormones tend to affect the other hormone. The most notable link between testosterone levels and the subsequent effect on estrogen levels is through an enzyme – aromatase.

Aromatase, also known as estrogen synthase, primarily works to make estrogen from androgens. It belongs to a large family of enzymes called cytochrome P450 and is found in many tissues of the body including gonads (testes and ovaries), adrenal gland, adipose tissue, and brain. 

Androgens are hormones that help develop masculine features. They include testosterone and other structurally similar molecules that produce testosterone-like effects.

The development of sexual characteristics in both males and females is aided by androgen, however, males produce more androgens. These androgens are the substrate for aromatase which converts them into estrogens.

Intuitively, an increase in the body’s testosterone (androgens) levels can lead to raised production of estrogen through the enzyme aromatase.

Contrastingly, a decrease in the androgens can lead to decreased production of estrogen, which might lead to several clinical conditions.

Another mechanism that can be inferred from various hormonal loops in the body also suggests a relationship between estrogen and testosterone.

Both estrogen and testosterone, are regulated in the body through the hypothalamus-pituitary-gonadal (HPG) axis. This axis is controlled by the brain and helps maintain optimum levels of sex hormones in the body. 

Taking testosterone as an example, an increase (above normal) in its levels can suppress the GnRH (gonadotropin-releasing hormone) and consequently LH (luteinizing hormone).

This suppression leads to suppression of sex hormone production such as estrogen and testosterone. It should be noted that GnRH suppression usually occurs due to long-term increased levels of testosterone.  

Conditions that cause Hormonal Imbalance

Certain conditions tend to alter the function of aromatase and cause a ripple in this hormonal balance. These include:

• Aromatase excess syndrome⁵– characterized by an excess in the aromatase enzyme. As discussed above it can lead to low androgen levels and higher estrogen levels. 
• Hypogonadism– refers to the reduced testicular size and sub-normal testosterone levels. Low testosterone levels can lead to low substrates for the aromatase enzyme. Hence lower levels of estrogen.
• Aging– as people age, especially males, their testosterone levels tend to decrease. This decrease, once again, lowers the estrogen yield of the body.³
• Problems of the HPG axis – the HPG axis is a critical component of sexual hormonal balance. Condition like hypopituitarism, damage to the hypothalamus, or pituitary tumors will likely manipulate the production of estrogen and testosterone in the body. Upregulation or downregulation from the higher center (brain) modifies the testosterone levels, consequently causing estrogen levels to change. 

How to Naturally Fix your Testosterone Levels 

Naturally, you can induce your testosterone production in several ways. Some common examples are:

• Exercising regularly, especially weight training
• Eating a balanced diet containing protein, omega-3 fatty acids, fibers
• Enjoy adequate sleep
• Reduce a stressful lifestyle
• Spend more time doing what you like
• Have a good sexual life
• Use a natural supplement with clincially proven ingredients

Conclusion

The discussion so far in the literature does not give a conclusive indication of testosterone’s effects on estrogen.

Nevertheless, testosterone does seem to affect the levels of estrogens in both males and females. T-levels in the body can increase and decrease estrogen levels depending upon their levels.

Due to the many deleterious effects of hormonal imbalance, the relationship between testosterone and estrogen needs to be studied more extensively.

Future research might show an abstract relationship between the two notorious sex hormones and indicate the conclusive effect of testosterone on estrogen.

References:

1. www.ch.ic.ac.uk. (n.d.). Testosterone and Estradiol. [online] Available at: https://www.ch.ic.ac.uk/vchemlib/mim/bristol/testosterone/testost.htm.

2. Testosterone & Estrogen in Women: High vs. Low vs. Normal Levels. Accessed February 4, 2022. https://www.webmd.com/women/guide/normal-testosterone-and-estrogen-levels-in-women

3. Finkelstein JS, Lee H, Burnett-Bowie SAM, et al. Gonadal Steroids and Body Composition, Strength, and Sexual Function in Men. New England Journal of Medicine. 2013;369(11):1011-1022. doi:10.1056/nejmoa1206168
4. Schulster M, Bernie AM, Ramasamy R. The role of estradiol in male reproductive function. Asian Journal of Andrology. 2016;18(3):435. doi:10.4103/1008-682X.173932
5. Fukami M, Shozu M, Soneda S, et al. Aromatase excess syndrome: Identification of cryptic duplications and deletions leading to gain of function of CYP19A1 and assessment of phenotypic determinants. Journal of Clinical Endocrinology and Metabolism. 2011;96(6). doi:10.1210/JC.2011-0145
6. https://medlineplus.gov/genetics/condition/aromatase-excess-syndrome/#:~:text=Aromatase%20excess%20syndrome%20is%20a,in%20late%20childhood%20or%20adolescence.