While you reach out for help from Hormone Replacement Therapies… we believe it is important that you learn a little about hormones and how they work, so you understand how they can help you!
Hormones are chemicals that function as your body’s messengers to bring important biological information to your cells, tissues and organs. They regulate your metabolism, temperature, growth, sexual health, sleep, brain, heart, kidney and reproductive functions.
When your hormone levels are low, you will not function well or perform at your best. Hormone levels decline as you age and the receptor cells that receive the imortant biological messages become less efficient at accepting those messages over time. Through Hormone Replacement Therapy (HRT), your physician can help restore normal hormone levels including the primary hormones that can have a real impact on the quality of your life such as Testosterone, Human Growth Hormone, Thyroid, Estrogen, Progesterone, Cortisol, DHEA, Insulin, Melatonin and others.
These are some of the most important hormones in your body… and their function:
Human Growth Hormone
Growth hormone (GH or HGH) is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Human Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by somatotropic cells within the lateral wings of the anterior pituitary gland. Growth hormone or Somatropin for Injection rDNA is used as a prescription drug in medicine to treat children’s growth disorders and adult growth hormone deficiency (AGHD). Growth Hormone decline is normally seen in middle-aged adults experiencing menopause or andropausal (male menopaue) symptoms. In the United States, it is only available legally from pharmacies, by prescription from a doctor. In recent years in the United States, some doctors have started to prescribe growth hormone in HGH-deficient older patients to increase vitality and help reverse the signs and symptoms of aging. The efficacy and safety of this use for HGH has been tested in a variety of medical research and clinical trials. HGH is considered a very complex hormone with many of its functions still waiting to be discovered. In its role as an anabolic agent, HGH has been abused by competitors in sports, bodybuilding and even the Olympics.
Testosterone, the male sex hormone is a steroid hormone from the androgen group. Testosterone is primarily secreted in the testicles of males and the ovaries of females, although small amounts are also secreted by the adrenal glands in women. It is the principal male sex hormone and an anabolic steroid. In men, testosterone plays a key role in the development of male reproductive tissues such as the testis and prostate as well as promoting secondary sexual characteristics such as increased muscle, bone mass, deep voice, and the growth of body hair. In addition, testosterone is essential for health and well-being as well as the prevention of osteoporosis (bone loss).
Estrogen / Estradiol
Estrogen is the female sex hormone. The three major naturally occurring estrogens in women are estrone (E1), estradiol (E2), and estriol (E3). Estradiol is the predominant estrogen during reproductive years. During menopause, estrone (E1) is the predominant circulating estrogen and during pregnancy estriol (E3) is the predominant circulating estrogen in terms of serum levels. Though estriol (E3) is the most plentiful of the three estrogens it is also the weakest, whereas estradiol (E2) is the strongest with a potency of approximately 80x that of estriol. Estradiol is the most important estrogen in non-pregnant females who are before and menopause stage of life. However, during pregnancy this role shifts to estriol, and in postmenopausal women estrone becomes the primary form of estrogen in the body. Another type of estrogen called estetrol (E4) is produced only during pregnancy. All of the different forms of estrogen are synthesized from androgens, specifically testosterone and androstenedione, by the enzyme aromatase.
Estradiol is a female sex hormone. Estradiol is abbreviated E2 as it has two hydroxyl groups in its molecular structure. Estrone has one (E1) and estriol has three (E3). Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect. As discussed above, Estradiol is the predominant estrogen during the reproductive years. During menopause, estrone (E1) is the predominant circulating estrogen and during pregnancy estriol (E3) is the predominant circulating estrogen in terms of serum levels. Estradiol is also present in males, being produced as an active metabolic product of testosterone. The serum levels of estradiol in males (14 – 55 pg/mL) are roughly comparable to those of postmenopausal women (< 35 pg/mL). Estradiol has not only a critical impact on reproductive and sexual functioning, but also affects other organs, including the bones.
Estradiol, like other steroids, is derived from cholesterol. A fraction of androstenedione is converted to testosterone, which in turn undergoes conversion to estradiol by an enzyme called aromatase. In an alternative pathway, androstenedione is aromatized to estrone, which is subsequently converted to estradiol.
Progesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestogens, and is the major naturally occurring human progestogen.
In women, progesterone levels are relatively low during the preovulatory phase of the menstrual cycle, rise after ovulation, and are elevated during the luteal phase, as shown in diagram below. Progesterone levels tend to be < 2 ng/ml prior to ovulation, and > 5 ng/ml after ovulation. If pregnancy occurs, human chorionic gonadotropin is released maintaining the corpus leuteum allowing it to maintain levels of progesterone.
Melatonin promotes sleepiness. In humans, melatonin is produced by the pineal gland, a small endocrine gland located in the center of the brain. Circadium Rythm – the melatonin signal forms part of the system that regulates the sleep-wake cycle by chemically causing drowsiness and lowering the body temperature, but it is the central nervous system that controls the daily cycle in most components of the paracrine and endocrine systems.
Infants’ melatonin levels become regular in about the third month after birth, with the highest levels measured between midnight and 08:00 (8 AM). In humans, 90% of melatonin is cleared in a single passage through the liver, a small amount is excreted in urine and a small amount is found in saliva.
Human melatonin production decreases as a person ages and as children become teenagers, the nightly schedule of melatonin release is delayed, leading to later sleeping and waking times.
Production of melatonin by the pineal gland is inhibited by light to the retina and permitted by darkness. Its onset each evening is called the dim-light melatonin onset (DLMO). When used several hours before sleep according to the phase response curve for melatonin in humans, small amounts (0.3 mg) of melatonin shift the circadian clock earlier, thus promoting earlier sleep onset and morning awakening.
Besides its function as synchronizer of the biological clock, melatonin also exerts a powerful antioxidant activity. Melatonin is an antioxidant that can easily cross cell membranes and the blood?rain barrier. This antioxidant is a direct scavenger of radical oxygen and nitrogen species. Melatonin works with other antioxidants to improve the overall effectiveness from each antioxidant.
Oxytocin may be considered the Love Hormone and hormone studies have begun to investigate oxytocin’s role in various sexual behaviors, including orgasm, social recognition, pair bonding, anxiety, and maternal behavior. There is some evidence that oxytocin promotes bonding and tribal behavior. Hormones have an impact on behavior and Oxytocin seems to foster the trust of accepted group members and rejection of outsiders. This kind of behavior is exhibited in the strong maternal bond a mother has with her own child versus others. The oxytocin receptor gene (OXTR) has also been associated with social traits such as aggression.
Insulin is a peptide hormone produced by the pancreas and is central to regulating carbohydrate, sugar (glucose) and fat metabolism in the body. Insulin helps bring sugar (glucose) into your body’s cells to use for energy. The brain also depends on glucose as its primary fuel and red blood cells use only glucose as a fuel. Insulin causes cells in the liver, muscles and fat tissue to take up sugar (glucose) from the blood and store it. In the liver and muscles glucose is converted and stored as glycogen. In the fatty tissue cells known as adipocytes, it is converted and stored as triglycerides.
Insulin is secreted as needed by the pancreas preventing the use of fat as an energy source and inducing the body to properly absorb and convert excess glucose to glycogen and triglycerides. Insulin serves to remove excess sugar (glucose) from the blood which would otherwise become toxic to the body. When blood sugar or glucose levels fall below a certain level, the body is signaled to begin using stored sugar as an energy source through glycogenolysis, which breaks down the glycogen stored in the liver and muscles into glucose, which can then be utilized as an energy source by the body. Glycogenolysis occurs primarily in the liver and is stimulated by the hormones glucagon from the pancreas and epinephrine (adrenaline). When blood glucose levels fall there is an increase in glucagon secretion from the pancreas accompanied by a decrease in insulin secretion so the body uses glucose for energy instead of storing it. When blood glucose levels rise, insulin is released to help the cells absorb sugar and to store any excess sugar as glycogen and triglycerides thereby maintaning proper glucose levels in the body. Gluconeogenesis helps to maintain the glucose level in the blood so that the brain and muscles can extract sufficient glucose from it to meet their metabolic demands.
Insulin also signals amino acid uptake by body cells and has other anabolic effects throughout the body. When you’ve been sick or injured, or if you’re recovering from surgery, insulin helps you heal by bringing amino acids which are the building blocks of muscle protein to your injured muscles. Amino acids help repair muscular damage and help them regain their size and strength. If there isn’t enough insulin in your body when your muscles have been injured or when you are sick, amino acids can’t do their job.
In the absence of insulin or in conditions where insulin is too low, glucose is not taken up by body cells and the body begins to use fat as its source of energy. If your body is unable to secrete suffcient insulin as needed, overnight your liver will release too much glycogen into your blood stream creating a toxic condition. People with diabetes have too high a blood glucose level, also called high blood sugar or hyperglycemia. Diabetes is a disorder of the metabolism or the way the body uses digested food for energy.
When insulin is no longer is secreted (Diabetes1) or secreted in too low a level (Diabetes 2), blood sugar levels will be too high. In addition a person’s body may no longer effectively use insulin and a glucose build will result. Insulin therapy is used to treat diabetes by replenishing insulin the body needs to properly absorb and synthesize glucose (Blood Sugar). Patients with type 1 diabetes depend on external insulin which is usually injected subcutaneously for their survival because the hormone is no longer produced internally. Patients with type 2 diabetes are insulin resistant and suffer from an insulin deficiency.
The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is found in the neck below the thyroid cartilage or Adam’s apple. The thyroid gland controls how quickly the body uses energy, makes proteins and how sensitive the body is to other hormones. The thyroid gland participates in these biological processes by producing thyroid hormones, the main ones being triiodothyronine (T3) and (T4) thyroxine – also referred to as tetraiodothyronine.
T3 & T4 thyroid hormones regulate the rate of metabolism and affect the function of many other systems in the body. T3 and T4 are synthesized from both iodine and tyrosine. The thyroid also produces calcitonin, which plays a role in calcium homeostasis.
Hormonal output from the thyroid is regulated by thyroid-stimulating hormone (TSH) produced by the anterior pituitary, which itself is regulated by thyrotropin-releasing hormone (TRH) produced by the hypothalamus. The most common hormonal imbalance problems of the thyroid gland consist of an overactive thyroid gland, referred to as hyperthyroidism, and an underactive thyroid gland, referred to as hypothyroidism. Hypothyroidism is treated with hormone replacement therapy (HRT) using a hormone medication such as levothyroxine which is typically required to be taken for the rest of the patient’s life. Thyroid hormone treatment is given under the care of a licensed physician and can take a few weeks to become effective in order to alleviate symptoms.
Cortisol, also known as hydrocortisone, is a steroid hormone or glucocorticoid produced by the adrenal glands. It is released in response to stress. Its primary functions of cortisol are to increase blood sugar through gluconeogenesis which is the release of glycogen (stored sugar) from the liver and muscle. Cortisol also suppresses the immune system, and aids in fat, protein and carbohydrate metabolism. Cortisol hormone prevents the release of substances in the body that cause inflammation. Cortisol stimulates gastric-acid secretion and inhibits loss of sodium from he body. Too much cortisol can weaken the activity of the immune system, counteract insulin, inhibit collagen and bone formation.
Hydrocortisone is used to treat endocrine, gland and hormone disorders, arthritis, lupus, skin disease, allergies, autoimmune disorders, swelling, asthma or other breathing problems.
Prolactin is a peptide hormone made by the pituitary gland. Pregnant women have high levels of prolactin which helps to make breast milk. During pregnancy, prolactin levels increase and after the baby is born prolactin stays high if a mother is breast-feeding. In women who do not breast-feed, prolactin levels return to normal soon after they give birth. After months of breast-feeding, prolactin levels may also return to normal levels even if a woman is still breast-feeding.
The pituitary gland in men and non-pregnant women also produce prolactin but at a much lower level. Prolactin hormone levels are different throughout the day with the highest levels occur during sleep and shortly after you wake up which is very similar to Human Growth Hormone. Prolactin levels also get higher during times of physical or emotional stress as do cortisol levels.
Leptin is a protein hormone that plays a key role in regulating energy intake and energy expenditure including appetite, hunger and metabolism. It is one of the most important adipose or fatty tissue-derived hormones. Leptin inhibits appetite and signals the body that it has had enough to eat. The level of circulating leptin is proportional to the total amount of fat in the body.
The absence of leptin or its receptor cells can lead to uncontrolled food intake resulting obesity. Fasting or following a very-low-calorie diet lowers leptin levels which signals hunger to the brain. Leptin is more sensitive to starvation than to overfeeding and leptin levels change more when less food is eaten than when more is eaten.
DHEA is known as Dehydroepiandrosterone, as androstenolone or prasterone, and is a very important steroid hormone. DHEA is known for being the most abundant circulating steroid hormone in human beings. DHEA hormoe is produced in the adrenal glands, in the gonads and in the brain where it functions to assist with metabolism and synthesis of androgen and estrogen sex hormones.
DHEA reaches its peak levels in the morning and regular exercise and a restricted diet help increase DHEA in the body. Naturally, DHEA is produced from cholesterol and converted to the hormone pregnenolon by enzymes and then to DHEA. For hormone supplementation, DHEA hormone supplements may be produced from wild yam or soy.
Taking too much of a DHEA supplement could cause irritability and aggressiveness so as with all anti-aging supplements careful dosing is important.
Although DHEA is predominantly a precursor to more potent androgens such as testosterone and estrogen, DHEA has some direct androgenic effect as well. Precursors are the substances that are converted by the body into hormones. Like Testosterone and HGH, DHEA production peaks in persons mid-20s and production gradually declines with age along with Testosterone, HGH, progesterone and estrogen production. DHEA supplements can help increase the level of these hormones and provide some healt benefits like boosting adrenal gland, strengthening the immune and nervous system, slow some efects of aging, increasing energy, improving mood, focus and memory, and building muscle strength.
Most people take DHEA supplements for Anti-Aging purposes and it is not permitted for body-building or professional sports including Olympic athletes. Since DHEA levels decline with age along with HGH and Testosterone, hormone replacement therapy may inlcude DHEA. Some small clinical studies have reported positive anti-aging effects from the use of DHEA supplements.
Human chorionic gonadotropin (HCG) is a hormone produced during pregnancy that is made by the developing placenta after conception. Human chorionic gonadotropin or HCG is as an ovulation inducer in place of LH or luteinizing hormone. When mature ovarian follicles exist, ovulation can be triggered by the administration of HCG injections and ovulation will happen between 38 and 40 hours after the HCG injection. HCG is also used by some weight loss doctors and hormone therapy doctors to help patients manage weight and counteract the effects of testosterone replacment therapy.
Follicle-stimulating hormone (FSH) is a hormone synthesized and secreted by gonadotrophs of of the pituitary gland. FSH is responsible for regulating development, growth, puberty and reproductive functions of the body. FSH and luteinizing hormone (LH) act together in reproduction. An increase in FSH secretion causes ovulation in women. Menopuase is the most common reason for too high a serum of FSH concentration in women as the gonads no longer provide the feedback loop to shut down FSH secretion. In men, too low an FSH level signifies the shutting down of the gonads (hypogonadism) during Andropause (the male menopause) and adversely affects the production and quality of sperm. Hypogonadism is chracterized by a decline in the free testosterone available to men for use by their bodies.
Luteinizing hormone (LH), is also known as lutropin or lutrophin and is a hormone produced by gonadotroph cells in the pituitary gland. In females an increase in LH triggers ovulation and the development of the corpus luteum. In males LH serves as an interstitial cell-stimulating hormone stimulating the testes’ Leydig cells to produce testosterone. LH works together with FSH in both men and women.