Getting older can bring changes you notice straight away: workouts may take longer to recover from, sleep might feel less predictable, and maintaining muscle can require more effort than it did ten years ago.
Hormones are sometimes blamed for all of this. The reality is more interesting and more complicated.
Men do experience hormonal changes with age, but there is no sudden hormonal cliff equivalent to menopause. Testosterone, growth hormone, and melatonin tend to decline gradually, while other hormones change relatively little. Lifestyle, body composition, medication, and underlying health conditions can influence the picture too (Mayo Clinic, 2025; Young, 2025).
Understanding those changes can make it easier to separate ordinary ageing from symptoms worth discussing with a healthcare professional.
Testosterone Usually Declines Gradually
Testosterone gets much of the attention when men talk about aging, and there is a genuine reason for that.
Testosterone production generally decreases with age. Mayo Clinic reports that testosterone levels in men fall by roughly 1% per year after age 40, although most older men still have levels within the standard range (Mayo Clinic, 2025).
Importantly, ageing is only part of the story. Research reviewed in Endotext indicates that weight gain, excess body fat, chronic illness, medication, lifestyle, and genetic factors can all influence testosterone levels. Some studies have even found that adiposity and other health conditions have a stronger association with low testosterone than chronological age itself (Bhasin et al., 2022).
That distinction matters when considering hormone-related symptoms or treatments. Testosterone and the growth hormone system, for example, are separate pathways and should not be treated as interchangeable. Anyone trying to understand that distinction in more detail can Read Article, which compares how testosterone therapy and sermorelin act on different hormonal systems. The latter signals the pituitary to release growth hormone rather than directly increasing testosterone.
Low Testosterone Isn’t the Same as Getting Older
Lower testosterone can be associated with changes in sexual desire, erectile function, muscle mass, body fat, mood, and energy. The difficulty is that none of those symptoms belongs exclusively to testosterone deficiency.
Poor sleep can make someone tired. Stress can affect libido. Certain medicines can alter hormone levels. Obesity and obstructive sleep apnea can also be associated with low testosterone (Mayo Clinic, 2025).
For this reason, symptoms alone can’t confirm low testosterone.
The Endocrine Society recommends diagnosing hypogonadism only when a man has compatible symptoms or signs and testosterone concentrations that are consistently and unequivocally low. Its guidance also recommends confirming an initially low result with a repeat morning fasting testosterone measurement (Bhasin et al., 2018).
In other words, feeling different at 45 than you did at 25 doesn’t automatically mean you have a hormone disorder.
Growth Hormone Changes With Age Too
Testosterone is only one part of the hormonal aging story.
Growth hormone, produced by the pituitary gland, is released in pulses and plays a role in metabolism and body composition. Its secretion decreases substantially with age, particularly because the size of the nighttime growth hormone pulses becomes smaller. Levels of insulin-like growth factor 1 (IGF-1), much of which is produced by the liver in response to growth hormone, also tend to fall (Bartke et al., 2026).
This age-related decline is sometimes called the somatopause, although it shouldn’t be interpreted as evidence that older adults need growth hormone treatment.
Research reviewed by Endotext found that giving growth hormone to healthy older adults can alter lean mass and body fat, but improvements in physical performance, strength, and aerobic capacity have generally been inconsistent or unimpressive. Older adults can also be more sensitive to adverse effects (Bartke et al., 2026).
A lower hormone level with age, therefore, isn’t automatically a deficiency that needs correcting.
Sleep Hormones Can Shift as Well
Anyone who has found that sleep becomes lighter or more fragmented with age may be interested to know that melatonin also changes over time.
Melatonin helps regulate the body’s sleep-wake cycle. According to the MSD Manual, melatonin is among the hormones that tend to decline with ageing, and this reduction may contribute to age-related changes in circadian rhythms (Young, 2025).
Cortisol and thyroid hormones behave differently. They generally remain relatively stable or decline only slightly as people age. This is another reason it is misleading to describe ageing as though every hormone simply falls at the same rate.
The endocrine system is a network, not a row of identical fuel gauges.
What About Muscle, Body Fat, and Recovery?
Men often become interested in hormones because they notice physical changes rather than numbers on a blood test.
Ageing is associated with lower skeletal muscle mass and strength and, commonly, greater body fat. Endotext estimates that skeletal muscle mass can decrease substantially between early adulthood and old age, although the rate varies considerably between individuals (Bhasin et al., 2022).
Hormones contribute to that process, but they aren’t the only contributors. Activity levels, nutrition, chronic health conditions, and changes in the nervous and muscular systems all matter.
That is useful news because some influences on healthy aging remain within everyday control. Staying physically active, particularly through resistance exercise, eating adequately, getting regular sleep and managing existing health conditions can support strength and general wellbeing even though nobody can stop hormonal aging altogether.
When Is It Worth Speaking to a Doctor?
Occasional tiredness or a bad week at the gym is rarely enough to draw conclusions about hormone levels.
Persistent or unexplained changes deserve more attention. Examples might include a sustained reduction in sexual desire, erectile difficulties, unexplained loss of muscle or strength, persistent fatigue or other symptoms affecting quality of life.
A clinician can consider the wider picture instead of assuming testosterone is responsible. That may mean reviewing sleep, weight changes, medications, and existing health conditions before deciding whether hormone testing is appropriate.
Medical testing matters because treatment isn’t automatically beneficial simply because a hormone level is lower than it once was.
The Endocrine Society advises against routinely prescribing testosterone therapy to every man aged 65 or older who has a low testosterone result. Decisions should instead consider symptoms, consistently low measurements, individual health circumstances, potential benefits and possible risks (Bhasin et al., 2018).
Research also shows why expectations need to stay realistic. In NIH-supported trials involving older men with low testosterone, testosterone treatment improved sexual function, but its effects on walking ability and vitality were smaller. As then-NIA Director Richard J. Hodes put it, the research “clarifies questions about some of its potential benefits,” while further study was needed to understand risks (National Institute on Aging, 2016).
Healthy Aging Is Bigger Than One Hormone
Hormones certainly change as men grow older, but they don’t tell the whole story.
Two men of the same age can have very different testosterone levels, body compositions, sleep patterns, and overall health. A number on a lab report also means little without context.
Perhaps the most useful approach is to pay attention to changes rather than chase the hormone levels of your twenties. Good sleep, regular physical activity, balanced nutrition, and appropriate healthcare remain relevant at every age.
And if something genuinely feels wrong, guessing is rarely as useful as getting it investigated.
Conclusion
Men’s hormones change throughout adulthood, usually gradually rather than all at once. Testosterone, growth hormone and melatonin commonly decline with age, while other parts of the endocrine system remain comparatively stable.
Those biological shifts can overlap with changes in sleep, sexual function, muscle and body composition, but similar symptoms can have many causes. Age alone doesn’t diagnose a hormone deficiency, and a single symptom or test result shouldn’t determine treatment.
Getting older changes the hormonal landscape. Understanding what those changes mean (and what they don’t mean) can help men make better-informed decisions about their long-term health.
References
Bartke, A., Chandrashekar, V., & others. (2026). Growth hormone and aging. Endotext. National Center for Biotechnology Information.
Bhasin, S., Brito, J. P., Cunningham, G. R., Hayes, F. J., Hodis, H. N., Matsumoto, A. M., Snyder, P. J., Swerdloff, R. S., Wu, F. C., & Yialamas, M. A. (2018). Testosterone therapy in men with hypogonadism: An Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism, 103(5), 1715–1744.
Bhasin, S., et al. (2022). Age-related changes in the male reproductive system. Endotext. National Center for Biotechnology Information.
Mayo Clinic. (2025, March 26). Male menopause: Myth or reality? Mayo Foundation for Medical Education and Research.
National Institute on Aging. (2016, February 17). NIH-supported trials test hormonal therapy in older men with low testosterone levels. National Institutes of Health.
Young, W. F., Jr. (2025). Effects of aging on the endocrine system. MSD Manual Consumer Version.