Adult growth hormone deficiency (GHD), also called human growth hormone (HGH) deficiency, is a significant concern for aging adults. The impact can be seen and felt as it often leads to faster physical aging, slower metabolism, weight gain, mental decline, fatigue, and ailing health.
HGH deficiency can happen at any time in life, from childhood to old age – and anywhere in between. The cause can be identifiable or unknown or attributed to the natural decline in growth hormone production as we age. Because GH levels begin to decrease by the time most people enter their thirties, the effects are often noticeable when people are in their fifties or older.
With growth hormone influencing nearly every area of the body, the impact on a person’s life can be severe. Fatigue and impaired cognitive performance can lead to mistakes or poor performance on the job. Declining sexual desire and functions can cause strife in a relationship. An aging appearance can lead to depression, low self-esteem, and a lack of confidence. Health problems associated with GH deficiency in adults can destroy one’s cherished independence.
What is growth hormone deficiency?
Growth hormone deficiency is a medical condition that occurs when the somatotropic cells in the anterior pituitary gland no longer produce enough GH for the body’s many needs.
Adult GH deficiency differs significantly from that in children when the primary function of growth hormone is to fuel physical growth. GH works directly on the cells of the muscles and bones with the help of its mediating hormone, insulin growth factor 1 (IGF-1). Together, IGF-1 and GH regenerate new cells and facilitate growth. It should also be known that GH is the direct stimulator of IGF-1 production by the liver.
Low HGH is problematic for adults who may experience declining health, frailty, memory loss, bone fractures, depression, insomnia, and overwhelming fatigue. Adult GHD can rob an individual of their independence, livelihood, and enjoyment in life. In extreme cases, GHD can lead to early morbidity and mortality, influencing lifespan. Adults with growth hormone deficiency are at a higher risk of cardiovascular disease and death from CVD.
Growth hormone levels are more challenging to measure than other hormones, as GH does not remain constant in the bloodstream. Pulsatile bursts of growth hormone occur once every few hours, often affected by exercise and food intake. Deep, slow-wave sleep is when the majority of GH enters the bloodstream, remaining for only a few minutes as it races to its receptor cells.
The normal GH level range is as follows:
- Adult females: 1 to 14 ng/mL
- Adult males: 0.4 to 10 ng/mL
Levels lower than those listed could lead to a diagnosis of GHD. However, testing for growth hormone deficiency is more complicated than that. Adults often undergo IGF-1 testing, as insulin growth factor 1 levels do not change as much as HGH. Measuring IGF-1 first thing in the morning before eating often provides a better look at GH levels.
The normal IGF-1 reference range in adults, according to LabCorp, is as follows:
| Age | Female (ng/mL) | Male (ng/mL) |
| 26 – 30 | 91 to 308 | 101 to 307 |
| 31 – 35 | 84 to 281 | 95 to 290 |
| 36 – 40 | 79 to 259 | 90 to 278 |
| 41 – 45 | 74 to 239 | 84 to 270 |
| 46 – 50 | 70 to 225 | 81 to 263 |
| 51 – 55 | 65 to 216 | 74 to 255 |
| 56 – 60 | 60 to 207 | 68 to 247 |
| 61 – 65 | 57 to 202 | 64 to 240 |
| 66 – 70 | 52 to 196 | 59 to 230 |
| 71 – 75 | 48 to 191 | 53 to 222 |
| 76 – 80 | 42 to 185 | 45 to 207 |
| 81 – 85 | 39 to 177 | 40 to 194 |
| 86 – 90 | 34 to 169 | 33 to 176 |
Having IGF-1 levels lower than the numbers shown could indicate adult growth hormone deficiency.
It is estimated that approximately 1 in 10,000 individuals have adult-onset GHD. Many people diagnosed with GHD during childhood continue to require HGH therapy as adults. Additionally, many children with low growth hormone levels go undiagnosed until much later in life, when they develop other symptoms associated with GHD. Families may not always know that short stature in childhood could be due to GH deficiency.
Why do adults need growth hormone?
Once a child reaches full adult height, growth hormone no longer increases bone length. The growth plates close, and future growth is no longer possible. That does not mean the role of GH is done. Adults continue to require an abundant supply of growth hormone for the following functions:
- Maintaining healthy body composition (lean-to-fat mass ratio)
- Keeping bones strong
- Promoting circulation and heart health
- Supporting metabolic functions
- Maintaining healthy sexual responses and hormone production
- Stimulating cognitive functions and emotional well-being
- Promoting cellular regeneration for all areas of the body
- Supporting immune system functions
Because low growth hormone levels in adults can interfere in these crucial areas of life, turning to HGH therapy can have a significant impact on health and well-being. HGH helps adults maintain attention, executive functions, and memory as they age, keeping spatial ability and cognitive performance.
Since growth hormone also influences crucial neurotransmitters, optimized levels can help avoid unwanted mood changes, anxiety, and depression so that people get the most out of life.
HGH supports healthy body composition, lipid profile, heart health, immunity, and overall well-being. Maintaining normal GH levels helps keep the body physiologically and psychologically fit by ensuring that all growth hormone receptor cells get the essential signals they require to perform their functions.
What causes GH deficiency in adults?
The majority of adult GHD conditions occur in adulthood. However, some adults who had childhood-onset GH deficiency may still require treatment as adults, including those with congenital causes that led to decreased growth hormone secretion.
As many as 25% of patients with a head injury or subarachnoid hemorrhage may experience HGH deficiency. Tumors, radiation, surgery, and other problems with the pituitary gland are leading causes of low growth hormone levels.
GHD occurs because the anterior pituitary gland cannot secrete enough growth hormone to reach all the body’s receptor cells. Whether congenital or acquired, the result is the same – symptoms of low HGH levels affect daily life.
The leading causes of adult growth hormone deficiency include:
- Traumatic brain injury (TBI)
- Tumor of the pituitary gland or hypothalamus
- Treatment (surgery, radiation) for the tumor, as mentioned above
- Infections such as tuberculosis, toxoplasmosis, fungal, pneumocystis carinii
- Diseases such as sarcoidosis, amyloidosis, histiocytosis X, lymphocytic hypophysitis, granulomatous hypophysitis
- Vascular causes such as Sheehan’s syndrome, pituitary apoplexy, subarachnoidal hemorrhage
- Treatment with monoclonal antibody therapies, immune checkpoint inhibitors, somatostatin analogs, interferons
- Age-related decline
- Unknown or undefined causes
As with adults, children have many of the same causes of GHD, such as tumors, brain injuries, and problems with the hypothalamic-pituitary axis, although they are more likely to be diagnosed with congenital issues than adults.
Types of growth hormone deficiency
Growth hormone deficiency that is present at birth falls under the congenital category. The causes of some childhood-onset GHD can be structural defects in the brain or genetic mutations. Genetics typically does not play a role in adult-onset GH deficiency, as these issues are usually caught early in life when the child does not grow at a typical pace.
Acquired and idiopathic are the two most common types of adult-onset GHD. Age-related growth hormone decline falls under idiopathic as there is no identifiable reason, such as when a tumor or brain injury leads to acquired HGH deficiency.
Problems with the pituitary gland, whether due to injury, illness, tumor, or other reasons, are the most common cause of acquired GHD.
The easiest way to sum up the three primary types of growth hormone deficiency is as follows:
- Acquired GHD: later onset due to issues surrounding the pituitary gland or hypothalamus.
- Congenital GHD: structural or genetic issues present at birth causing reduced GH secretion.
- Idiopathic GHD: no known or identifiable cause.
Symptoms of growth hormone deficiency
The signs and symptoms of growth hormone deficiency in adults can vary from one person to another due to the many ways the body uses GH. Symptoms often develop based on which areas receive the least growth hormone signaling.
For example, when the brain does not receive enough GH, concentration, learning, mood, and memory experience significant problems. When the gonads do not receive a plentiful supply of growth hormone, low sex drive, erectile dysfunction, vaginal dryness, and reduced pleasure are possible.
Because HGH also stimulates testosterone production, a precursor to estradiol (estrogen), the functions associated with those hormones suffer. As with HGH and IGF-1, testosterone helps with bone mineral density, which is crucial for overall heart health.
Testosterone stimulates erythropoiesis (red blood cell production) in bone marrow. With HGH and IGF-1 promoting cellular reproduction, a decline in any of these hormones can lead to trouble with circulation.
Human growth hormone is a direct stimulator of metabolism, as is testosterone. When these hormone levels decline, the body stores fat rather than using the food you consume for energy. You gain weight and feel fatigued. Lack of energy further reduces exercise, increasing this vicious cycle. Between the lack of movement and reduced cellular regeneration, lean muscle decreases.
Adult growth hormone deficiency symptoms affect people in many ways, including:
- Increased body fat, especially around the midsection (belly)
- Fatigue, lethargy, low endurance
- Reduced sexual interest and function
- Decreased lean muscle mass
- Joint pains and stiffness
- Reduced strength
- Decreased bone mineral density
- Anemia
- Poor blood circulation
- Trouble sleeping
- High LDL and total cholesterol, and triglyceride levels
- Sensitivity to changes in temperature
- Depression, mood changes, anxiety, stress, irritability
- Reduced exercise capacity
- Hair thinning or loss
- Dry, thinning skin, wrinkles, discoloration, sagging
- Impaired cardiac function
- Decreased attention, learning, processing speed, memory recall
- Reduced insulin sensitivity
- Social isolation
- Decreased quality of life
These symptoms vary considerably from those in children with GHD, whose primary issues are lack of growth, immature facial features compared to their peers, and possible chubby body build. Delayed puberty and impaired hair growth are also possible.
Quality of life can suffer significantly for adults living with untreated growth hormone deficiency. Body aches, poor self-image, depression, fatigue, health problems, and low libido can remove the joy in life.
Undiagnosed or untreated GHD can significantly increase the risk of developing additional health problems, including:
- Osteoporosis
- Type 2 diabetes
- Heart disease
- High blood pressure
- Infertility
- Dementia
- High cholesterol
How is growth hormone deficiency diagnosed in adults?
Adult GHD diagnosis begins with a thorough review of the patient’s symptoms. During the initial consultation, it is important to detail all your symptoms. You can refer to the list provided here to help notate anything of interest or concern.
One of the questions you will be asked is if you have had any head injuries, as damage to the pituitary gland or hypothalamus can lead to GH deficiency. Be sure to mention if you have any headaches or problems with your balance or eyesight, as those issues could indicate a potential tumor. An MRI may be necessary to rule out a tumor if warning signs point to it.
Diagnostic testing for GHD is a comprehensive blood analysis that measures various serum levels, including but not limited to the following:
- Comprehensive metabolic panel (CMP): measures 14 different substances
- Complete blood count (CBC): helps detect anemia and some cancers
- Lipid panel: to measure cholesterol and triglycerides
- Thyroid hormone panel: to ensure there are no issues with the thyroid gland
- Total testosterone: to ensure that this is not the problem (many Low T symptoms mimic those of GHD)
- Insulin growth factor 1: to check for GHD
Adults are less likely to undergo the serum stimulation test for GHD than children. Measuring IGF-1 levels and a symptoms review can often determine adult growth hormone deficiency.
Preparing for the blood test does not take much. You will visit a local lab early in the morning for the best results. Do not consume food or beverages other than water after midnight before the test. Also, get a good night’s sleep to maximize your GH production.
GHD testing takes place at a laboratory collection facility. One of the lab technicians will check your veins to find the best one, apply a tourniquet around the upper arm, sterilize the area with an alcohol prep pad, and insert the needle into the vein.
After drawing a few tubes of blood, a bandage will be applied over the site for you to keep in place for a couple of hours. You will then be free to go about your day – and have a good breakfast.
The blood test results will let the doctor know if you have GHD, any other hormonal imbalance, anemia, high cholesterol, or other issues associated with the checked panels.
Treatment for GHD in adults
A diagnosis of GHD paves the way for customized treatment using recombinant human growth hormone (rHGH) therapy. Injectable HGH provides superior results, sending increased supplies of growth hormone to the body’s many GH receptor cells.
Because rHGH is bioidentical to the body’s naturally produced growth hormone, it is readily accepted by the receptors for use.
The brands of HGH chosen by our hormone doctors provide safe, effective results with various injectable options. These brands include:
- Norditropin
- Omnitrope
- Genotropin
- Saizen
- Humatrope
- Zomacton
Another option for some adults is sermorelin, a peptide hormone that stimulates the pituitary gland to increase growth hormone secretion. Sermorelin is beneficial for people with early-stage GHD that has not progressed to the point where significant symptoms are present. For some people, a combination approach using both HGH and sermorelin can bring excellent results by immediately increasing growth hormone levels and slowly increasing natural GH production (sermorelin).
HGH therapy goes to work in the body with the first injection. While you may not notice any changes for a few weeks, your body’s cells enjoy the immediate benefits of increased growth hormone signaling. The responses include influence on inflammatory markers, insulin sensitivity, and lipid profiles.
Early benefits during the first month of HGH treatment include better sleep, mood, focus, energy, and sex drive. As the months pass, you will start to notice a loss of belly fat, increased lean muscle mass, reduced body aches and stiffness, improved memory, less depression and stress, and a more youthful appearance.
If you suffer from GHD, HGH treatment is your best option, as that is the only way to provide your body with a continual supply of HGH
Please know there is no such thing as homeopathic HGH, as over-the-counter products do not contain HGH. The explosion of these “so-called HGH products” on the market has even prompted the American Association of Homeopathic Pharmacists (AAHP) to issue a warning about homeopathic HGH.
If you have symptoms of HGH deficiency, the best option is to contact our hormone doctors for a free consultation. We can assess your symptoms and determine if testing and treatment are right for you.
Our hormone therapy clinic provides affordable, safe, legal HGH treatment that produces superior results. Let us help you enjoy a better quality of life.