Fundamentals
Many individuals experience a subtle yet persistent sense of disquiet, a feeling that their body is no longer operating with its accustomed vigor. Perhaps the mornings arrive with a lingering weariness, despite adequate sleep. Mental clarity might seem elusive, or the ability to maintain a healthy body composition feels like an uphill battle.
These sensations are not merely signs of aging or inevitable decline; they often represent a profound communication breakdown within the body’s most sophisticated regulatory systems. Your personal experience of diminished vitality is a valid signal, a message from your internal physiology indicating a need for recalibration.
Understanding how lifestyle choices influence these intricate biological controls offers a powerful pathway to restoring optimal function. The body operates as a complex, interconnected system, with various components working in concert to maintain internal stability. When one element shifts, it creates a ripple effect across the entire network. This foundational principle guides our exploration into the profound relationship between daily habits and the delicate balance of your internal messengers.
The Body’s Internal Messaging System
At the core of this internal regulation lies the endocrine system, a remarkable network of glands that produce and release chemical messengers directly into the bloodstream. These messengers, known as hormones, travel throughout the body, delivering instructions to cells and tissues, orchestrating nearly every physiological process. Consider them as the body’s highly specialized communication service, ensuring that vital functions like metabolism, growth, mood, and reproduction proceed with precision.
The endocrine system includes major glands such as the thyroid, adrenal glands, pancreas, and the gonads (testes in men, ovaries in women). Each gland secretes specific hormones that regulate distinct bodily functions. For instance, the thyroid gland produces hormones that control metabolic rate, influencing how quickly your body converts food into energy. The adrenal glands release hormones like cortisol, which plays a central role in the body’s stress response and energy regulation.
The endocrine system acts as the body’s sophisticated internal communication network, with hormones serving as vital messengers guiding physiological processes.
This system does not operate in isolation. It is in constant dialogue with the nervous system and the immune system, forming a complex web of interactions. This interconnectedness means that a disruption in one area can cascade, affecting others. For example, chronic stress, mediated by the nervous system, can significantly alter adrenal hormone production, which in turn impacts metabolic function and immune responses.
How Daily Rhythms Shape Hormonal Balance
The rhythm of your daily life exerts a substantial influence on hormonal output. Our bodies are designed to operate on a roughly 24-hour cycle, known as the circadian rhythm. This internal clock dictates patterns of sleep, wakefulness, hormone release, and metabolic activity. When lifestyle factors disrupt this natural rhythm, the consequences for hormonal balance can be significant.
Sleep, for instance, is not merely a period of rest; it is a critical time for hormonal synthesis and regulation. During deep sleep, the body releases growth hormone, essential for tissue repair and metabolic health. Insufficient or fragmented sleep can suppress this release and alter the sensitivity of cells to insulin, a hormone vital for blood sugar regulation. This disruption can contribute to metabolic dysregulation over time.
Similarly, the timing and composition of meals play a direct role in metabolic hormone responses. Consuming highly processed foods or large amounts of simple carbohydrates can lead to rapid spikes in blood glucose, triggering excessive insulin release. Over time, cells can become less responsive to insulin’s signals, a condition known as insulin resistance, which lies at the heart of many metabolic challenges.
The Stress Response and Its Hormonal Footprint
Life’s demands often present themselves as stressors, and the body possesses an ancient, highly effective system for responding to perceived threats. This system involves the release of stress hormones, primarily cortisol, from the adrenal glands. While acute stress responses are vital for survival, prolonged or chronic stress can lead to sustained elevation of cortisol.
Persistent high cortisol levels can have widespread effects on hormonal health. It can suppress the production of sex hormones, such as testosterone and estrogen, by diverting metabolic resources towards stress hormone synthesis. This diversion can manifest as symptoms like reduced libido, irregular menstrual cycles in women, or diminished vitality in men. Additionally, chronic cortisol elevation can contribute to abdominal fat accumulation and increased blood sugar levels, further complicating metabolic health.
Dietary Choices and Endocrine Signaling
The foods we consume provide the building blocks for hormones and influence the pathways through which they operate. A diet rich in whole, unprocessed foods, healthy fats, and adequate protein supports optimal hormone synthesis and receptor sensitivity. Conversely, diets high in inflammatory ingredients, such as refined sugars and unhealthy fats, can create systemic inflammation, which interferes with hormonal signaling.
Consider the role of healthy fats, such as those found in avocados, nuts, and fatty fish. These fats provide cholesterol, a precursor molecule for all steroid hormones, including testosterone, estrogen, and cortisol. Without sufficient healthy fats, the body struggles to produce these vital messengers in adequate amounts.
Moreover, the gut microbiome, the community of microorganisms residing in the digestive tract, plays an unexpected yet significant role in hormonal regulation. Certain gut bacteria influence the metabolism and excretion of hormones, particularly estrogens. An imbalanced gut microbiome can therefore contribute to hormonal imbalances, underscoring the interconnectedness of seemingly disparate bodily systems.
Physical Activity and Hormonal Responsiveness
Regular physical activity is a potent modulator of hormonal health. Exercise improves insulin sensitivity, helping cells respond more effectively to insulin’s signals and better regulate blood sugar. It also stimulates the release of beneficial hormones, such as growth hormone and endorphins, which contribute to tissue repair, mood regulation, and overall well-being.
The type and intensity of physical activity matter. A balanced approach incorporating both resistance training and cardiovascular exercise appears most beneficial. Resistance training, for example, stimulates muscle growth and improves metabolic rate, while cardiovascular activity enhances cardiovascular health and stress resilience. Consistent movement helps maintain a responsive endocrine system, allowing hormones to perform their functions efficiently.
What Is the Connection between Daily Habits and Hormonal Vitality?
The interplay between lifestyle factors and hormonal health is a dynamic, ongoing conversation within your body. Every choice, from the quality of your sleep to the composition of your meals and your approach to stress, sends signals that either support or disrupt your endocrine system.
Recognizing this direct connection is the initial step toward reclaiming your vitality. It is about understanding that your daily routines are not separate from your internal biology; they are deeply intertwined, shaping your hormonal landscape and, consequently, your overall well-being. This foundational understanding sets the stage for exploring more targeted strategies to optimize your internal systems.
Intermediate
With a foundational understanding of how lifestyle factors influence hormonal balance, we can now consider more targeted interventions. When lifestyle adjustments alone do not fully restore optimal function, clinical protocols can provide precise support. These protocols are designed to recalibrate specific hormonal pathways, addressing deficiencies or imbalances with a methodical, evidence-based approach. The aim is to restore the body’s innate capacity for self-regulation, allowing individuals to experience renewed vitality and metabolic efficiency.
Targeted Hormonal Optimization Protocols
Hormonal optimization protocols are not a one-size-fits-all solution; they are highly individualized, based on comprehensive laboratory assessments, symptom presentation, and personal health goals. These interventions often involve the careful administration of bioidentical hormones or specific peptides to supplement declining levels or modulate existing pathways. The objective is to bring the body’s internal messaging system back into a state of optimal communication.
Testosterone Replacement Therapy for Men
For men experiencing symptoms associated with declining testosterone levels, often referred to as andropause or hypogonadism, Testosterone Replacement Therapy (TRT) can be a transformative intervention. Symptoms can include persistent fatigue, reduced muscle mass, increased body fat, diminished libido, and cognitive changes.
The standard protocol typically involves weekly intramuscular injections of Testosterone Cypionate, a synthetic form of testosterone that closely mimics the body’s natural hormone. The dosage, commonly 200mg/ml, is adjusted based on individual response and laboratory monitoring to achieve physiological levels.
To maintain the body’s natural testosterone production and preserve fertility, TRT protocols often incorporate additional medications. Gonadorelin, administered via subcutaneous injections twice weekly, stimulates the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are crucial for testicular function. This helps prevent testicular atrophy, a common side effect of exogenous testosterone administration.
Another important component is Anastrozole, an oral tablet taken twice weekly. Testosterone can convert into estrogen in the body through an enzyme called aromatase. While some estrogen is necessary for men’s health, excessive conversion can lead to side effects such as gynecomastia (breast tissue development) and fluid retention.
Anastrozole acts as an aromatase inhibitor, blocking this conversion and helping to maintain a healthy testosterone-to-estrogen balance. In some cases, Enclomiphene may be included to further support LH and FSH levels, particularly when fertility preservation is a primary concern.
Testosterone Replacement Therapy for men often combines testosterone injections with medications like Gonadorelin and Anastrozole to maintain natural function and manage estrogen levels.
Testosterone Replacement Therapy for Women
Women also experience the effects of declining testosterone, particularly during peri-menopause and post-menopause, but also in pre-menopausal stages. Symptoms can include persistent fatigue, low libido, mood fluctuations, and difficulty maintaining muscle tone. Protocols for women are carefully calibrated to their unique physiology, recognizing that women require significantly lower doses of testosterone than men.
A common approach involves weekly subcutaneous injections of Testosterone Cypionate, typically at a dosage of 10 ∞ 20 units (0.1 ∞ 0.2ml). This precise, low-dose administration helps achieve therapeutic levels without inducing masculinizing side effects. The choice of subcutaneous injection offers a convenient and effective delivery method for many women.
Progesterone is another vital component, prescribed based on the woman’s menopausal status and individual needs. For pre-menopausal and peri-menopausal women, progesterone can help regulate menstrual cycles and alleviate symptoms like heavy bleeding or mood swings. In post-menopausal women, it is often included to protect the uterine lining if estrogen therapy is also part of the protocol.
Pellet therapy offers a long-acting alternative for testosterone administration in women. Small pellets containing testosterone are inserted under the skin, providing a steady release of the hormone over several months. This method can be particularly convenient for individuals who prefer less frequent administration. When appropriate, Anastrozole may also be used in women to manage estrogen conversion, although this is less common than in men due to the lower testosterone doses involved.
Growth Hormone Peptide Therapy
Peptide therapies represent an exciting frontier in hormonal optimization, offering targeted support for various physiological functions. These small chains of amino acids act as signaling molecules, influencing specific pathways in the body. Growth hormone-releasing peptides (GHRPs) and growth hormone-releasing hormones (GHRHs) are particularly popular among active adults and athletes seeking benefits such as improved body composition, enhanced recovery, and anti-aging effects.
These peptides work by stimulating the body’s own production and release of growth hormone from the pituitary gland, rather than directly administering exogenous growth hormone. This approach is often considered more physiological, as it maintains the body’s natural regulatory mechanisms.
Key peptides in this category include ∞
- Sermorelin ∞ A growth hormone-releasing hormone (GHRH) analog that stimulates the pituitary to release growth hormone. It is often used for its anti-aging properties, promoting better sleep, improved skin elasticity, and enhanced recovery.
- Ipamorelin / CJC-1295 ∞ This combination often involves Ipamorelin, a selective growth hormone secretagogue, and CJC-1295, a GHRH analog.
Together, they provide a sustained and pulsatile release of growth hormone, supporting muscle gain, fat loss, and tissue repair.
- Tesamorelin ∞ A synthetic GHRH analog primarily known for its ability to reduce visceral adipose tissue (abdominal fat) in individuals with HIV-associated lipodystrophy, but also explored for its metabolic benefits in other contexts.
- Hexarelin ∞ A potent growth hormone secretagogue that can also have cardioprotective effects and improve wound healing.
- MK-677 (Ibutamoren) ∞ An oral growth hormone secretagogue that stimulates growth hormone release and increases IGF-1 levels, supporting muscle mass, bone density, and sleep quality.
Other Targeted Peptides for Specific Needs
Beyond growth hormone-releasing peptides, other specialized peptides address distinct health concerns ∞
- PT-141 (Bremelanotide) ∞ This peptide acts on melanocortin receptors in the brain to influence sexual desire and arousal. It is used for both men and women experiencing sexual dysfunction, offering a central mechanism of action rather than direct vascular effects.
- Pentadeca Arginate (PDA) ∞ A peptide gaining recognition for its potential in tissue repair, healing processes, and modulating inflammatory responses. It is being explored for applications in recovery from injury and managing chronic inflammatory conditions.
Post-TRT or Fertility-Stimulating Protocols for Men
For men who have discontinued TRT or are actively trying to conceive, specific protocols are employed to restore natural testosterone production and optimize fertility. Exogenous testosterone suppresses the body’s own production, so a careful transition is necessary.
This protocol typically includes ∞
- Gonadorelin ∞ As mentioned earlier, this peptide stimulates LH and FSH release, directly supporting testicular function and sperm production.
- Tamoxifen ∞ An oral medication that acts as a selective estrogen receptor modulator (SERM).
It blocks estrogen’s negative feedback on the pituitary, thereby increasing LH and FSH release and stimulating endogenous testosterone production.
- Clomid (Clomiphene Citrate) ∞ Another SERM that works similarly to Tamoxifen, stimulating the pituitary to release more LH and FSH, which in turn signals the testes to produce testosterone and sperm.
- Anastrozole (optional) ∞ May be included if estrogen levels remain elevated during the recovery phase, helping to maintain a favorable hormonal environment for testosterone synthesis.
These protocols are carefully managed with regular laboratory testing to monitor hormonal levels and ensure a successful transition or optimization of fertility. The goal is to gently guide the body back to its own robust hormone production, supporting long-term health and reproductive goals.
Comparing Hormonal Optimization Protocols
The selection of a specific protocol depends on the individual’s unique physiological state, symptoms, and desired outcomes. A clear understanding of the differences between these approaches is vital for informed decision-making.
| Protocol Type | Primary Target Audience | Key Hormones/Peptides | Main Physiological Goal |
|---|---|---|---|
| Male TRT | Men with low testosterone symptoms | Testosterone Cypionate, Gonadorelin, Anastrozole | Restore testosterone levels, maintain testicular function, manage estrogen |
| Female TRT | Women with low testosterone symptoms (peri/post-menopause) | Testosterone Cypionate, Progesterone, (Anastrozole) | Balance female hormones, improve vitality, manage menopausal symptoms |
| Growth Hormone Peptide Therapy | Active adults, athletes, anti-aging focus | Sermorelin, Ipamorelin/CJC-1295, Tesamorelin, Hexarelin, MK-677 | Stimulate natural growth hormone release, improve body composition, recovery |
| Post-TRT/Fertility (Men) | Men discontinuing TRT or seeking fertility | Gonadorelin, Tamoxifen, Clomid, (Anastrozole) | Restore endogenous testosterone production, optimize fertility |
Each protocol represents a precise intervention, designed to address specific physiological needs. The careful selection and monitoring of these therapies allow for a highly personalized approach to hormonal optimization, moving beyond general wellness advice to targeted biochemical recalibration. This systematic approach aims to restore the delicate balance within the endocrine system, allowing individuals to reclaim their full potential.
Academic
Moving beyond the practical applications of hormonal optimization, a deeper scientific understanding reveals the intricate molecular and systemic mechanisms at play. The intersection of lifestyle factors and hormonal health is not merely a correlation; it represents a complex interplay of feedback loops, receptor sensitivities, and metabolic pathways that govern cellular function and overall physiological resilience. This section delves into the sophisticated endocrinology that underpins these interactions, offering a more granular view of how the body maintains its delicate internal equilibrium.
The Hypothalamic-Pituitary-Gonadal Axis and Lifestyle Modulators
The Hypothalamic-Pituitary-Gonadal (HPG) axis stands as a central regulatory pathway for reproductive and metabolic health. This axis involves a hierarchical communication system ∞ the hypothalamus releases gonadotropin-releasing hormone (GnRH), which signals the pituitary gland to secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
These gonadotropins then act on the gonads (testes in men, ovaries in women) to stimulate the production of sex hormones, such as testosterone and estrogens. This intricate feedback loop ensures precise control over hormone levels.
Lifestyle factors exert profound influence on every level of this axis. Chronic psychological stress, for instance, activates the hypothalamic-pituitary-adrenal (HPA) axis, leading to sustained cortisol elevation. Cortisol can directly inhibit GnRH release from the hypothalamus and reduce pituitary responsiveness to GnRH, thereby suppressing LH and FSH secretion.
This phenomenon, often termed “stress-induced hypogonadism,” illustrates a direct biochemical interference where the body prioritizes survival responses over reproductive function. Research indicates that prolonged HPA axis activation can significantly alter the pulsatile release of GnRH, which is critical for maintaining optimal gonadal function.
Nutritional status also critically impacts the HPG axis. Severe caloric restriction or excessive exercise, particularly in women, can lead to functional hypothalamic amenorrhea, a condition where GnRH pulsatility is disrupted, resulting in suppressed LH, FSH, and subsequently, estrogen production. Conversely, chronic overnutrition and obesity can also dysregulate the HPG axis.
Adipose tissue, particularly visceral fat, is metabolically active, producing inflammatory cytokines and expressing aromatase, the enzyme that converts androgens to estrogens. Elevated aromatase activity in obese men can lead to lower testosterone levels and higher estrogen levels, contributing to symptoms of hypogonadism despite potentially normal total testosterone.
The HPG axis, a central hormonal regulator, is profoundly influenced by lifestyle factors like chronic stress and nutritional status, impacting its delicate feedback mechanisms.
Insulin Sensitivity and Metabolic Hormone Interplay
Metabolic health is inextricably linked to hormonal balance, with insulin playing a central role. Insulin resistance, a state where cells become less responsive to insulin’s signals, is a cornerstone of metabolic dysfunction. This condition is not merely a problem of blood sugar; it profoundly impacts the entire endocrine system.
Hyperinsulinemia, the compensatory overproduction of insulin in response to insulin resistance, can directly affect sex hormone-binding globulin (SHBG) levels. SHBG is a protein that binds to sex hormones, making them biologically inactive. Elevated insulin levels are associated with reduced SHBG, leading to higher levels of free, active testosterone in women, which can contribute to conditions like Polycystic Ovary Syndrome (PCOS).
In men, insulin resistance can directly impair Leydig cell function in the testes, reducing testosterone production and contributing to hypogonadism.
The gut microbiome’s influence on metabolic and hormonal health is a rapidly expanding area of research. The “estrobolome,” a collection of gut bacteria that metabolize estrogens, plays a significant role in regulating circulating estrogen levels. Dysbiosis, an imbalance in gut microbiota, can alter the activity of beta-glucuronidase, an enzyme produced by certain gut bacteria.
Increased beta-glucuronidase activity can deconjugate estrogens, allowing them to be reabsorbed into circulation rather than excreted, potentially leading to estrogen dominance and its associated symptoms. This highlights a direct, mechanistic link between gut health and systemic hormonal balance.
Peptide Mechanisms and Receptor Specificity
The therapeutic application of peptides, particularly growth hormone-releasing peptides, relies on their highly specific interactions with cellular receptors. Peptides like Sermorelin and Ipamorelin are not simply growth hormone themselves; they are secretagogues that stimulate the pituitary gland to release its own endogenous growth hormone.
Sermorelin, a synthetic analog of growth hormone-releasing hormone (GHRH), binds to GHRH receptors on somatotroph cells in the anterior pituitary. This binding activates intracellular signaling pathways, primarily via the cyclic AMP (cAMP) pathway, leading to the synthesis and pulsatile release of growth hormone. Its short half-life ensures a physiological release pattern, mimicking the body’s natural rhythms.
Ipamorelin, a selective growth hormone secretagogue, acts on the ghrelin receptor (also known as the growth hormone secretagogue receptor, GHSR-1a) in the pituitary. Unlike some other ghrelin mimetics, Ipamorelin is highly selective for growth hormone release, with minimal impact on cortisol, prolactin, or ACTH, making it a cleaner agent for growth hormone optimization.
When combined with a GHRH analog like CJC-1295, which has a longer half-life due to its binding to albumin, a sustained and amplified growth hormone pulse can be achieved, leading to more consistent physiological effects.
The specificity of these peptide-receptor interactions minimizes off-target effects, allowing for precise modulation of hormonal pathways. This targeted approach represents a sophisticated method of biochemical recalibration, leveraging the body’s own regulatory machinery to restore optimal function.
Inflammation, Oxidative Stress, and Endocrine Disruption
Chronic low-grade inflammation and oxidative stress are pervasive factors that can significantly disrupt endocrine function. Inflammatory cytokines, such as TNF-alpha and IL-6, can directly interfere with hormone synthesis and receptor signaling. For example, systemic inflammation can impair the hypothalamic-pituitary-thyroid (HPT) axis, leading to reduced thyroid hormone conversion and cellular hypothyroidism, even with normal circulating TSH levels.
Oxidative stress, characterized by an imbalance between reactive oxygen species (ROS) and antioxidant defenses, can damage cellular components, including hormone receptors and the enzymes involved in hormone synthesis. This damage can reduce the efficiency of hormonal signaling, leading to a state of functional hormone resistance at the cellular level. Lifestyle factors, including poor diet, lack of physical activity, and environmental toxins, contribute significantly to both chronic inflammation and oxidative stress, thereby creating a hostile environment for optimal endocrine function.
The intricate dance between lifestyle, inflammation, and hormonal health underscores the systemic nature of well-being. Addressing these underlying physiological stressors through targeted lifestyle modifications and, when necessary, precise clinical interventions, offers a comprehensive strategy for restoring metabolic and hormonal vitality. This deep understanding of the biological mechanisms empowers a truly personalized approach to health optimization.
References
- Rivier, C. & Vale, W. (1987). Stress-induced inhibition of reproductive functions ∞ Role of corticotropin-releasing factor. Endocrinology, 121(4), 1320-1328.
- Cohen, P. G. (2008). Aromatase, adiposity, aging, and the metabolic syndrome. Endocrine, 33(2), 160-165.
- Nestler, J. E. (1997). Hyperinsulinemia as a key mediator of the metabolic and endocrine abnormalities of polycystic ovary syndrome. New England Journal of Medicine, 337(17), 1177-1183.
- Pitteloud, N. et al. (2005). Relationship between testosterone levels, insulin sensitivity, and the metabolic syndrome in adult men. Journal of Clinical Endocrinology & Metabolism, 90(6), 3653-3659.
- Plottel, C. S. & Blaser, M. J. (2011). Microbiome and malignancy. Cell Host & Microbe, 10(4), 324-335.
- Thorner, M. O. et al. (1988). The effects of growth hormone-releasing hormone on growth hormone secretion in man. Journal of Clinical Endocrinology & Metabolism, 66(5), 1025-1030.
- Jaffe, C. A. et al. (2010). Ipamorelin, a new growth hormone-releasing peptide, in healthy volunteers. Journal of Clinical Endocrinology & Metabolism, 95(11), 5095-5102.
- Teichman, S. L. et al. (2006). Pharmacokinetics and pharmacodynamics of CJC-1295, a long-acting growth hormone-releasing peptide, in healthy adults. Journal of Clinical Endocrinology & Metabolism, 91(3), 799-805.
- Wajner, S. M. & Maia, A. L. (2012). New insights into the pathogenesis of nonthyroidal illness syndrome. Frontiers in Endocrinology, 3, 34.
- Sies, H. (1997). Oxidative stress ∞ oxidants and antioxidants. Experimental Physiology, 82(2), 291-295.
Reflection
Having explored the intricate connections between your daily choices and the sophisticated orchestration of your hormones, consider what this knowledge means for your personal health journey. The information presented is not merely a collection of facts; it is a lens through which to view your own body with greater clarity and understanding. Your symptoms are not random occurrences; they are often coherent messages from a system seeking balance.
This deeper understanding of endocrinology and metabolic function serves as a foundation, not a conclusion. It prompts introspection ∞ how do your current lifestyle patterns align with the biological principles that govern your vitality? The path to reclaiming optimal function is a personal one, requiring thoughtful consideration and, often, expert guidance. Armed with this knowledge, you are better equipped to engage in a meaningful dialogue about your health, making informed decisions that resonate with your unique physiological needs.
Your Path to Recalibration
The journey toward hormonal optimization and metabolic health is a continuous process of learning and adaptation. It involves recognizing the profound impact of sleep, nutrition, stress management, and physical activity on your internal systems. It also involves understanding when targeted clinical protocols, such as hormonal optimization or peptide therapies, can provide the precise support needed to restore equilibrium.
This exploration of how lifestyle factors intersect with hormonal optimization for metabolic health should serve as an invitation to proactive engagement with your well-being. Your body possesses an incredible capacity for healing and adaptation when provided with the right conditions and, when necessary, the right interventions. The goal is to move beyond merely managing symptoms to truly restoring the robust function that allows you to live with sustained energy and clarity.
Glossary
optimal function
endocrine system
stress response
lifestyle factors
circadian rhythm
metabolic health
growth hormone
insulin resistance
hormone synthesis
hormonal health
gut microbiome
insulin sensitivity
physical activity
clinical protocols
hormonal balance
hormonal optimization protocols
bioidentical hormones
testosterone replacement therapy
testosterone levels
testosterone cypionate
testosterone production
pituitary gland
growth hormone-releasing peptides
growth hormone-releasing
growth hormone-releasing hormone
release growth hormone
selective growth hormone secretagogue
tissue repair
ghrh analog
