Is Low Testosterone Baked Into Aging?

2026-08-20
Testosterone
Is Low Testosterone Baked Into Aging?

I like making chocolate chip cookies, but have this big debate every time I make them. I have to weigh the tastiness of a warm, gooey cookie with the impatience and tastiness of cold, tasty cookie dough. The key question is whether the current product (cookie dough) should be transformed into a different product down the line (a finished cookie). Interestingly, this is not so different from how our bodies determine which sex organs will develop. High levels of testosterone (the cookie dough) contribute to the development of male sex organs, while estrogen levels (the cookies) play an important part in female sexual reproductive development. Sometimes, however, the body may convert too much testosterone to estrogen, even in men.

 

Hypogonadism is a condition where the gonads (testes, for men) fail to produce enough testosterone and/or sperm. The word comes from the ancient Greek hypo-, meaning “below” or “under,” gonad, meaning “seed” or “offspring,” and -ism, which is used to denote a condition. Rates of hypogonadism vary depending on measurement criteria, affecting between 3 and 38% of men.[1,2,3] Primary hypogonadism, defined as testicular dysfunction (not making enough cookie dough), is rather rare, affecting fewer than 1% of males.[1,4,5] Secondary hypogonadism, which occurs when the hormone systems are dysfunctional (baking too many cookies), is much more common.[1,4,5] Hypogonadism rates increase with age and weight, with higher risks for males around middle age or older and those with a BMI above 30.[1,4]

 

Testosterone is an androgen: a “male” sex hormone.[6] Hormones are signaling molecules, and androgens signal in a crucial way. Testosterone and other androgens promote the creation of specific “male” proteins.[6]  (Fun fact: you may have heard of anabolic steroids. “Anabolic” refers to things that increase the production of proteins. Many anabolic steroids mimic testosterone). These proteins are what create the male anatomy, promote libido, and help define metabolic rate.[6] When testosterone is low, such as with hypogonadism, symptoms relate directly to the loss of testosterone function:[7,8]

  • Reduced libido
  • Erectile dysfunction
  • Fatigue
  • Low fertility
  • Loss of muscle mass
  • Insulin resistance
  • Obesity
 

So, what’s actually happening inside the body with hypogonadism? There are myriad possible causes, but one possible culprit for sufferers (especially overweight sufferers) is an enzyme called aromatase.[9] Aromatase is a protein enzyme that converts testosterone into estradiol, also called E2.[9] Estradiol is an estrogen and is the critical sex hormone for females during reproductive years.[9] Females produce androgens like testosterone, but at much lower concentrations.[9] Aromatase acts as the cookie baker, and mediates the conversion balance of male and female sex hormones. Much like a baker, aromatase “makes more cookies” in response to:[9]

  • Age
  • Obesity
  • Alcohol use
  • Some hormones

When aromatase increases, the balance of hormones shifts from cookie dough to cookies; from testosterone to estradiol and androgens to estrogens.[9]

 

Obesity increases aromatase activity, contributes to low testosterone levels, and is commonly associated with hypogonadism. So it makes sense that weight loss is a primary treatment goal for overweight individuals with low testosterone.[1] This is bad news for me and my love of cookies, though studies find that as little as 5% weight loss can improve testosterone levels.[1] 

 

Beyond weight loss, the typical treatment for many men with hypogonadism is testosterone replacement therapy (TRT). Testosterone may be delivered by nasal or skin gel, patches, oral pills, or injections.[10] TRT comes with a host of relatively mild side effects, including hair loss, acne, skin changes, headache, nausea, and vomiting.[10] More serious adverse effects can also occur, including polycythemia, a blood disorder of an abnormally high concentration of red blood cells, which  should be monitored by a healthcare professional.[4,10] One potentially major side effect of TRT is an increase in the chances of infertility, making this a poor option for some men.[10,11]

 

Clinical trials are currently underway looking at different pathways to increase testosterone, including aromatase inhibition.[7,11] In early results, inhibiting aromatase in overweight males led to a rapid normalization of testosterone levels and increases in motile sperm count, which may help with fertility issues for some men.[7,11] These studies also found side effects, including headache and increased red blood cells, blood pressure, and prostate-specific antigen (PSA).[7] Aromatase inhibition still needs more long term evidence, but if these clinical trials are successful, clinicians may bake up a new way to treat low testosterone - and that’s pretty sweet.

 

Creative Director Benton Lowey-Ball, MWC, BS, BFA

 

 

References:

[1] Anawalt BD, O’Connor KM, Grossmann M. Adult male hypogonadism: a review. JAMA. 2026 Jun 23;335(24):2146-59. https://doi.org/10.1001/jama.2026.8526

 

[2] Carman W. The prevalence, incidence, and treatment rates of hypogonadism in men across geographies: a systematic literature review. Value in Health. 2013 Jan 1. https://doi.org/10.1016/j.jval.2013.03.315

 

[3] Mulligan T, Frick MF, Zuraw QC, Stemhagen A, McWhirter C. Prevalence of hypogonadism in males aged at least 45 years: the HIM study. International journal of clinical practice. 2006 Jul;60(7):762-9. https://doi.org/10.1111/j.1742-1241.2006.00992.x

 

[4] Davidiuk AJ, Broderick GA. Adult-onset hypogonadism: evaluation and role of testosterone replacement therapy. Translational andrology and urology. 2016 Dec;5(6):824. https://doi.org/10.21037/tau.2016.09.02

 

[5] Bhasin S, Brito JP, Cunningham GR, Hayes FJ, Hodis HN, Matsumoto AM, Snyder PJ, Swerdloff RS, Wu FC, Yialamas MA. Testosterone therapy in men with hypogonadism: an endocrine society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism. 2018 May;103(5):1715-44. https://doi.org/10.1210/jc.2018-00229

 

[6] Marieb EN, Hoehn K. Human anatomy & physiology. [11th Edition]. [Hoboken, New Jersey]: Pearson; [2019]. p. 601-641, 1060.

 

[7] Jones TH, Dobs AS, Randeva H, Moore W, Parkin JM. Leflutrozole in male obesity-associated hypogonadotropic hypogonadism: Ph 2b double-blind randomised controlled trial. European journal of endocrinology. 2023 Sep;189(3):297-308. https://doi.org/10.1093/ejendo/lvad099

 

[8] Wu F, Zitzmann M, Heiselman D, Donatucci C, Knorr J, Patel AB, Kinchen K. Demographic and clinical correlates of patient-reported improvement in sex drive, erectile function, and energy with testosterone solution 2%. The journal of sexual medicine. 2016 Aug;13(8):1212-9. https://doi.org/10.1016/j.jsxm.2016.05.010

 

[9] Hussain A, Gilloteaux J. The human testes: estrogen and ageing outlooks. Translational Research in Anatomy. 2020 Sep 1;20:100073. https://doi.org/10.1016/j.tria.2020.100073

 

[10] Gurayah AA, Dullea A, Weber A, Masterson JM, Khodamoradi K, Mohamed AI, Ramasamy R. Long vs short acting testosterone treatments: a look at the risks. Urology. 2023 Feb 1;172:5-12. https://doi.org/10.1016/j.urology.2022.11.016

 

[11] Jones T, Dobs A, MacKinnon A, Parkin J. OR18-4 Beneficial Effect on Sperm Production of Leflutrozole in Men with Obesity-Associated Secondary Hypogonadotropic Hypogonadism: Results from a Phase II Study. Journal of the Endocrine Society. 2019 Apr;3(Supplement_1):OR18-4. https://doi.org/10.1210/js.2019-OR18-4


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