Two different things: deficiency and normal decline
Growth hormone output drops with age in all men, and most of that drop is normal rather than a disease. Growth hormone is released by the pituitary in pulses, largest during deep sleep, and both the size of those pulses and the liver’s production of IGF-1 in response decline gradually from early adulthood onward.
Adult growth hormone deficiency is something else: a medical diagnosis, usually caused by damage to the pituitary or hypothalamus. Common causes include pituitary tumors or surgery, radiation to the head, significant head injury, and deficiency that began in childhood. The Endocrine Society guideline on adult growth hormone deficiency states that confirmation through stimulation testing is usually required, unless there is a proven genetic or structural cause persisting from childhood.
| Age-related decline | Adult growth hormone deficiency | |
|---|---|---|
| Who | Every aging man | Usually men with pituitary or hypothalamic disease, injury or radiation |
| IGF-1 | Gradually lower for age | Often low, but can be normal |
| Diagnosis | Not a diagnosis | Stimulation testing, usually by an endocrinologist |
| Treatment | Lifestyle; sometimes off-label peptides | FDA-approved growth hormone, managed by endocrinology |
Signs and symptoms
The symptoms people link to falling growth hormone are real, but they are not specific. MedlinePlus lists fatigue, reduced muscle mass and lower bone density as possible effects of adult deficiency, and notes that growth hormone testing is not common in adults because other disorders are much more likely to cause these symptoms.
Men commonly describe:
- Lower energy and stamina.
- More fat around the middle and less muscle despite training.
- Slower recovery after exercise or injury.
- Poorer sleep quality.
- Thinner skin or reduced exercise capacity.
Each of these has more common explanations: low testosterone, poor sleep, sleep apnea, thyroid problems, anemia, depression, excess alcohol or too little protein. The evaluation looks at those first.
Your own growth hormone output also responds to everyday habits. Deep, regular sleep supports the main nightly pulse. Hard exercise, especially strength and interval training, triggers release. Excess abdominal fat blunts it, so losing visceral fat tends to help. Large, late meals and evening alcohol can dampen the overnight pulse. None of this turns back the clock, but men who fix sleep, training and body fat often find the symptoms they blamed on growth hormone ease considerably.
What an IGF-1 result shows, and what it does not
IGF-1 is the most practical blood marker of growth hormone activity. MedlinePlus explains that unlike growth hormone, which rises and falls in pulses, IGF-1 stays fairly stable through the day, which makes it a reliable way to track growth hormone in the body.
IGF-1 still has clear limits:
- Reference ranges are age-specific and differ between labs, so a result is read against men your age.
- Many things lower it: poor nutrition or a large calorie deficit, liver disease, uncontrolled diabetes and an underactive thyroid.
- A low-for-age result is not a diagnosis. It can prompt a closer look, but it does not prove deficiency.
- A normal result does not rule out deficiency in a man with pituitary disease, which is one reason stimulation testing exists.
Our page on the IGF-1 blood test covers ranges and preparation in more depth. At Ultimate Male, IGF-1 is part of the baseline labs before any peptide discussion, drawn on site at San Gabriel or Downey.
How true deficiency is diagnosed
Diagnosing adult growth hormone deficiency means provoking the pituitary and measuring how much growth hormone it can release. Stimulation tests include the insulin tolerance test, the glucagon test and an oral test using macimorelin, sold as Macrilen; its label is listed on DailyMed. These tests are done under supervision, usually by an endocrinologist, and they are reserved for men with a real reason to suspect pituitary disease.
If your history includes a pituitary tumor, brain surgery or radiation, a significant head injury, or deficiencies in other pituitary hormones, the right next step is endocrinology rather than a peptide. Our comparison of a men’s health clinic versus an endocrinologist explains when each makes sense.
Where sermorelin and tesamorelin honestly fit
Neither peptide is a treatment for true adult growth hormone deficiency. When deficiency is confirmed, the established treatment is FDA-approved growth hormone managed by endocrinology. Peptides belong to a different conversation: men with normal pituitary function, age-related decline and specific goals.
Sermorelin is the first 29 amino acids of growth-hormone-releasing hormone. It was FDA-approved as Geref and is now supplied by compounding pharmacies; using it in adults for sleep, recovery or body composition is outside its original approved indication. It prompts your own pituitary to release growth hormone in natural pulses, with IGF-1 rechecked on treatment. The sermorelin page covers who it suits, and our tesamorelin versus sermorelin comparison sets the two side by side.
Tesamorelin is FDA-approved, as Egrifta, to reduce excess abdominal fat in adults with HIV-associated lipodystrophy; its label is on DailyMed. Use for visceral fat in other men is off-label and needs glucose monitoring.
Some limits apply to both. Neither should be used with active cancer or an untreated pituitary problem. Both appear on the WADA prohibited list as growth-hormone-releasing factors, so tested athletes should not use them. And growth hormone itself is not offered for anti-aging; our page on whether HGH is legal for anti-aging explains why.
When symptoms need urgent care
Most concerns about growth hormone are not urgent, but pituitary problems can be. Go to the emergency room for a sudden, severe headache with vision loss or double vision, which can signal bleeding into a pituitary tumor. Men with known pituitary disease who develop severe weakness, vomiting, confusion or fainting also need emergency care, because other pituitary hormones such as cortisol may be failing.
Your next step
If you suspect your growth hormone is falling, the first useful step is a set of labs that looks at IGF-1 alongside testosterone, thyroid, blood sugar and blood counts. Call 626-319-5261 for the free 10-minute phone consultation. A PA-C or MD at San Gabriel or Downey reviews the results with you, refers to endocrinology when deficiency is possible, and otherwise explains honestly whether sermorelin, tesamorelin or no peptide at all fits your goals. Book online when you are ready.
