Aging affects nearly every hormone in the body, but the changes aren’t uniform. Some hormones drop sharply, others rise, and a few stay remarkably stable. The most well-known endocrine change with aging is the decline in sex hormones (estrogen in women, testosterone in men), but equally important shifts happen to growth hormone, the adrenal hormone DHEA, parathyroid hormone, insulin function, and melatonin. Together, these changes influence everything from bone density and muscle mass to sleep quality and blood sugar control.
Hormones That Decline With Age
The largest and most consistent hormonal drops involve growth hormone, DHEA, and the sex hormones. Growth hormone secretion falls steadily after about age 30, and by age 60 most people produce only low levels. Because growth hormone drives production of IGF-1 (a key signal for tissue repair and muscle maintenance), this decline contributes to the gradual loss of muscle mass, increased body fat, and thinner skin that many people notice in their 50s and 60s. This process is sometimes called “somatopause.”
DHEA, a hormone made by the adrenal glands that serves as a building block for both testosterone and estrogen, follows an even steeper curve. It peaks around age 25, then drops continuously. By age 85, DHEA levels are roughly 95% lower than their peak. This is one of the most dramatic hormonal declines in the entire body, and researchers believe it plays a role in the age-related loss of bone density, immune function, and general vitality.
In women, estrogen levels fall sharply during menopause, typically between ages 45 and 55. This sudden drop, rather than a gradual slide, is what makes menopause distinct from most other age-related endocrine changes. The loss of estrogen accelerates bone loss, raises cardiovascular risk, and triggers the hot flashes and sleep disruption that define the menopausal transition. Prolactin also decreases significantly in women after menopause.
In men, testosterone declines more gradually, dropping roughly 12 ng/dL per decade. There’s no sharp cutoff equivalent to menopause. Instead, men experience a slow reduction that can eventually lead to lower energy, reduced muscle mass, increased body fat, and changes in mood or sexual function. Not every man experiences noticeable symptoms from this decline.
Other hormones that decrease include aldosterone (which helps regulate blood pressure and fluid balance), calcitonin (involved in calcium regulation), and renin (part of the blood pressure control system).
Hormones That Rise With Age
While declining hormones get most of the attention, several hormones actually increase as you get older. Parathyroid hormone (PTH) is one of the most clinically significant. PTH controls calcium levels in the blood, and it rises with age partly because older adults tend to have lower vitamin D levels and absorb less calcium from food. The body compensates by releasing more PTH, which pulls calcium from bone to maintain blood levels. Over years, this accelerates bone loss and contributes to osteoporosis.
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) also rise. These are produced by the pituitary gland to stimulate the ovaries and testes. As the sex organs become less responsive, the pituitary ramps up production of FSH and LH in an attempt to maintain sex hormone levels. This is especially pronounced in postmenopausal women, where FSH levels can increase dramatically.
Norepinephrine, a stress hormone and neurotransmitter, tends to increase with aging. This may partly explain why older adults often have higher resting blood pressure and a stronger physiological response to stress, even when they report feeling less emotionally stressed.
Cortisol: Stable Overall, but the Pattern Shifts
Total cortisol production decreases slightly with age, yet blood levels remain about the same because the body breaks cortisol down more slowly. So the net amount circulating stays relatively constant. What does change is the daily rhythm. Cortisol normally peaks in the early morning and drops to its lowest point in the evening. In older adults, evening cortisol levels tend to be higher than in younger people, while morning levels stay similar. This flattened rhythm means the body spends more of the day exposed to elevated cortisol, which over time can affect memory, immune function, and sleep quality.
Blood Sugar Control Gets Harder
One of the most practically important endocrine changes with aging involves insulin and blood sugar regulation. Average fasting glucose rises by 6 to 14 mg/dL every decade after age 50. For a long time, this was attributed almost entirely to insulin resistance, where cells stop responding as efficiently to insulin. But more recent research paints a more nuanced picture.
A large study of over 32,000 adults without diabetes found that the insulin-producing beta cells in the pancreas lose function with age, independent of body weight or insulin resistance. In fact, some studies have found that insulin sensitivity actually improves in older adults, even as blood sugar control worsens. The real driver appears to be that the pancreas simply can’t secrete insulin as effectively as it once did. This means age itself is a risk factor for blood sugar problems, separate from weight gain or lifestyle.
Melatonin and Sleep Changes
The pineal gland, a small structure deep in the brain, produces melatonin to regulate the sleep-wake cycle. Melatonin production declines with aging in most people. One reason is that the pineal gland gradually calcifies over time, reducing its ability to produce melatonin. This results in lower nighttime melatonin peaks and a dampened rhythm, meaning the body’s signal for sleep becomes weaker and less well-timed. This contributes to the lighter, more fragmented sleep that many older adults experience, as well as the tendency to fall asleep earlier and wake earlier.
Thyroid Hormones Stay Mostly Stable
Unlike many other hormones, thyroid hormones (T3 and T4) remain relatively unchanged with normal aging. However, the normal range for TSH, the pituitary hormone that controls thyroid function, shifts upward. In adults under 65, a TSH above about 4.5 is typically considered elevated. But in people over 80, the normal range extends up to about 6.7. This matters because an older adult with a mildly elevated TSH may not actually have a thyroid problem. They may simply have a TSH level that’s normal for their age. Misinterpreting this can lead to unnecessary treatment.
Why Tissues Respond Differently
Hormone levels tell only part of the story. The other half is how well your tissues respond to those hormones. With aging, many tissues lose hormone receptors, the proteins on cell surfaces that detect and respond to hormonal signals. This reduced receptor density means that even when hormone levels are adequate, the signal doesn’t get through as effectively. It’s like turning up the volume on a radio with a damaged speaker. The result is a double hit in some systems: less hormone produced and a weaker response to whatever hormone remains.
This receptor loss helps explain why some age-related changes persist even when hormone levels are artificially restored through supplements or replacement therapy. The tissue itself has become less capable of responding, which limits how much benefit replacement can provide.