How GH Secretagogues Work and Their Potential for Anti-Aging
GH secretagogues function as somatostatin antagonists at the hypothalamic-pituitary level and can restore youthful GH secretion patterns in elderly subjects.
Fuh, V L; Bach, M A · Review
Research library — page 9
Browse more peptide research, methods and limitations.
State of the Art: Oral GH Secretagogues and Their Clinical Future
Oral GH secretagogues effectively increase GH and IGF-1 through a specific receptor, with clinical potential spanning GH deficiency, aging, and catabolic states, though their optimal therapeutic role remained to be defined.
Ghigo, E; Arvat, E; Camanni, F · Review
How Thymosin Alpha-1 Changes Shape to Interact With Immune Cells
Thymosin alpha-1 adopts a structured conformation with a beta-turn (residues 5-8) and alpha helix (residues 17-24) in membrane-like environments, suggesting this shape change is required for immune cell activation.
Grottesi, A; Sette, M; Palamara, T; Rotilio, G; Garaci, E; Paci, M · In Vitro
How the Bombesin Peptide Signals Your Brain to Stop Eating
GRP-R knockout mice completely lost bombesin-induced feeding suppression, demonstrating that GRP-R is the key receptor mediating this satiety signal.
Hampton, L L; Ladenheim, E E; Akeson, M; Way, J M; Weber, H C; Sutliff, V E; Jensen, R T; Wine, L J; Arnheiter, H; Battey, J F · Animal Study
BPC-157 Blocks Amphetamine's Effects and Prevents Drug Sensitivity Buildup
BPC-157 blocked acute amphetamine-induced stereotypy and prevented haloperidol-induced dopamine supersensitivity to amphetamine, without affecting normal baseline behavior.
Jelovac, N; Sikirić, P; Rucman, R; Petek, M; Perović, D; Konjevoda, P; Marović, A; Seiwerth, S; Grabarević, Z; Sumajstorcić, J; Dodig, G; Perić, J · Animal Study
How Ipamorelin and Other Growth Hormone Peptides Are Absorbed by the Body
Ipamorelin demonstrated approximately 20% nasal bioavailability in rats, superior to GHRP-2, GHRP-6, and two other peptides, supporting its potential for non-invasive nasal delivery.
Johansen, P B; Hansen, K T; Andersen, J V; Johansen, N L · Animal Study
High Blood Sugar Triggers Pancreatic Cells to Produce the Opioid Peptide Dynorphin
Glucose stimulation induced prodynorphin gene expression in pancreatic beta-cell lines, with dynorphin peptides being processed and secreted, suggesting a novel opioid-mediated feedback mechanism in glucose regulation.
Josefsen, K; Buschard, K; Sørensen, L R; Wøllike, M; Ekman, R; Birkenbach, M · In Vitro
How a Hybrid Antimicrobial Peptide Destroys Bacterial Membranes
The cecropin A-magainin 2 hybrid peptide disrupts membranes via a two-step mechanism, and leucine substitution analogs showed enhanced membrane disruption and antitumor activity with preserved low hemolytic toxicity.
Kang, J H; Shin, S Y; Jang, S Y; Lee, M K; Hahm, K S · In Vitro
Could Growth Hormone Peptides Help Thalassemia Patients With Stunted Growth?
GH secretagogues like GHRP-6 and hexarelin can stimulate growth hormone release through mechanisms distinct from GHRH, making them potentially useful for thalassemia patients with iron-damaged pituitary glands.
Karydis, I; Tolis, A; Tolis, G · Review
Natriuretic Peptides as Early Warning Signs of Heart Failure
BNP showed the most dramatic increase in ventricular tissue during heart failure progression and correlated most strongly with cardiac dysfunction severity, supporting its use as a heart failure biomarker.
Klinge, R; Hystad, M; Kjekshus, J; Karlberg, B E; Djøseland, O; Aakvaag, A; Hall, C · Animal Study
First Detection of Antimicrobial Peptide Lactoferricin Circulating in Human Blood
Lactoferricin was detected and quantified in human serum for the first time using SELDI affinity mass spectrometry, establishing its natural occurrence in the bloodstream.
Kuwata, H; Yip, T T; Yip, C L; Tomita, M; Hutchens, T W · In Vitro
New Method Reveals How Lactoferrin Breaks Down Into Antimicrobial Peptides in the Stomach
Affinity mass spectrometry enabled direct detection and quantification of lactoferricin and multiple lactoferrin-derived peptide fragments in human gastric contents, revealing the peptide generation process in detail.
Kuwata, H; Yip, T T; Yip, C L; Tomita, M; Hutchens, T W · In Vitro
Your Stomach Naturally Creates an Antimicrobial Peptide From Lactoferrin in Milk
Direct detection of lactoferricin generation in the human stomach after oral lactoferrin ingestion, providing the first in-vivo evidence of this bioactive peptide's natural formation during digestion.
Kuwata, H; Yip, T T; Tomita, M; Hutchens, T W · Clinical Trial
Discovery of a Unique Opioid Receptor That Controls Immune Cell Activation
The mu3 receptor on immune cells selectively binds opiate alkaloids (not endogenous opioid peptides), triggers nitric oxide release via constitutive nitric oxide synthase, and is present on macrophages, astrocytes, and leukemia cells.
Makman, M H; Dobrenis, K; Surratt, C K · In Vitro
BNP Blood Test Accurately Detects Weakened Heart Pumping in the General Population
Plasma BNP was superior to NT-ANP for detecting left ventricular systolic dysfunction in a general population, with particularly high sensitivity for moderate-to-severe cases.
McDonagh, T A; Robb, S D; Murdoch, D R; Morton, J J; Ford, I; Morrison, C E; Tunstall-Pedoe, H; McMurray, J J; Dargie, H J · Cross Sectional
How Heart Failure Medications Change Hormone Levels in Critically Ill Patients
Treatment of acute severe heart failure reduced BNP and ANP levels but not catecholamines or renin-angiotensin activity, indicating natriuretic peptides more accurately reflect clinical improvement.
Missouris, C G; Grouzmann, E; Buckley, M G; Barron, J; MacGregor, G A; Singer, D R · Clinical Trial
Adding Thymosin Alpha-1 to Interferon Therapy Improves Hepatitis C Treatment Response
Thymosin alpha-1 (1 mg twice weekly) combined with interferon-alpha-2b (3 MU three times weekly) produced superior biochemical and virological responses compared to interferon alone in treatment-naive chronic hepatitis C patients.
Moscarella, S; Buzzelli, G; Romanelli, R G; Monti, M; Giannini, C; Careccia, G; Marrocchi, E M; Zignego, A L · RCT
Growth Hormone Peptides Have Specific Receptors Throughout the Human Brain
Specific, high-affinity binding sites for GH secretagogues were identified in the human pituitary and multiple brain regions including hypothalamus and hippocampus, indicating CNS effects beyond GH release.
Muccioli, G; Ghè, C; Ghigo, M C; Papotti, M; Arvat, E; Boghen, M F; Nilsson, M H; Deghenghi, R; Ong, H; Ghigo, E · In Vitro
MK-677 Pill Reverses Muscle Breakdown From Calorie Restriction
MK-677 at 25 mg daily reversed diet-induced nitrogen wasting in healthy volunteers, increasing IGF-1 by 40% and producing sustained anabolic effects comparable to GH injections.
Murphy, M G; Plunkett, L M; Gertz, B J; He, W; Wittreich, J; Polvino, W M; Clemmons, D R · RCT
Multiple Receptor Types Explain Why Growth Hormone Peptides Affect the Heart and Brain
Multiple GHRP receptor subtypes exist in the pituitary, brain, and heart, with hexarelin binding cardiac tissue — explaining the cardiovascular effects of GH secretagogues beyond their GH-releasing activity.
Ong, H; Bodart, V; McNicoll, N; Lamontagne, D; Bouchard, J F · Review
Identifying a New Growth Hormone Peptide Receptor in the Pituitary
Photoaffinity labeling with modified hexarelin identified a specific GHRP receptor protein in pituitary membranes, confirming the existence of a distinct GH secretagogue receptor subtype.
Ong, H; McNicoll, N; Escher, E; Collu, R; Deghenghi, R; Locatelli, V; Ghigo, E; Muccioli, G; Boghen, M; Nilsson, M · In Vitro
What Happens to Mice Without Neuropeptide Y: Seizure Protection and Normal Appetite
NPY knockout mice had normal appetite and body weight but showed dramatically increased susceptibility to seizures and excitotoxicity, revealing NPY's primary role as an endogenous anticonvulsant.
Palmiter, R D; Erickson, J C; Hollopeter, G; Baraban, S C; Schwartz, M W · Animal Study
Higher Doses of Thymosin Alpha-1 Boost Cancer Treatment Effectiveness in Melanoma
Dose-escalation of thymosin alpha-1 in triple chemo-immunotherapy (cyclophosphamide + thymosin alpha-1 + interferon) produced dose-dependent increases in anti-tumor efficacy against B16 melanoma in mice.
Pica, F; Fraschetti, M; Matteucci, C; Tuthill, C; Rasi, G · Animal Study
Ipamorelin: The First Growth Hormone Peptide That Only Boosts GH Without Other Hormones
Ipamorelin released GH with potency similar to GHRP-6 but did not increase ACTH, cortisol, prolactin, or FSH even at doses 200-fold higher than effective GH-releasing doses, making it the first truly selective GH secretagogue.
Raun, K; Hansen, B S; Johansen, N L; Thøgersen, H; Madsen, K; Ankersen, M; Andersen, P H · Clinical Trial
Two Peptide Blood Tests Predict Heart Function and Survival After Heart Attack
NT-proBNP at 2-4 days post-MI correlated strongly with LVEF (r=-0.63) and was the strongest independent predictor of mortality. NT-proBNP ≥160 pmol/L identified high-risk patients. Adrenomedullin also predicted poor prognosis.
Richards, A M; Nicholls, M G; Yandle, T G; Frampton, C; Espiner, E A; Turner, J G; Buttimore, R C; Lainchbury, J G; Elliott, J M; Ikram, H; Crozier, I G; Smyth, D W · Cohort
Peptide-Based Tube Feeding Healed Surgical Wounds 30% Stronger Than Amino Acid Diets
Peptide-based enteral diets significantly improved surgical wound healing compared to equivalent amino acid-based diets in rats. Wound bursting pressure — the gold standard measure of wound strength — was 30% higher in the peptide-fed group (179±9 vs. 138±12 mmHg, P=0.02). Specifically, the dietary peptide carnosine (a dipeptide of beta-alanine and histidine) improved wound strength by 23% compared to a diet containing its constituent amino acids (143±10 vs. 116±8 mmHg, P=0.005). This demonstrates that peptides provide wound-healing benefits beyond what their individual amino acid components can deliver — peptides are not just pre-digested protein.
Roberts, P R; Black, K W; Santamauro, J T; Zaloga, G P · Animal Study
The Complete Guide to Natriuretic Peptide Blood Tests in Heart Disease
ANP and BNP are sensitive markers of cardiac volume and pressure overload with clinical utility in diagnosing heart failure, monitoring treatment, predicting prognosis, and screening for asymptomatic cardiac dysfunction.
Sagnella, G A · Review
A Milk-Derived Opioid Peptide Promotes Nerve Cell Growth
Beta-casomorphin-5 stimulated neurite outgrowth in Neuro-2a cells at picomolar concentrations via mu-opioid receptors, demonstrated by naloxone reversibility and DAMGO replication of the effect.
Sakaguchi, M; Murayama, K; Yabe, K; Satoh, M; Takeuchi, M; Matsumura, E · In Vitro
Discovery of the Orexins: Two New Brain Peptides That Control Hunger and Feeding
This landmark study identified two entirely new neuropeptides — orexin-A and orexin-B — both produced from the same precursor protein in the hypothalamus. These peptides bind to and activate two closely related G protein-coupled receptors that had previously been "orphan" receptors (receptors with no known ligand). Orexin-A and orexin-B have no structural similarity to any previously known regulatory peptides, making them a completely novel peptide family. They are produced by neurons in and around the lateral and posterior hypothalamus of rat brains. When injected into the brain, both peptides stimulated food consumption. Furthermore, fasting caused an increase in prepro-orexin mRNA, indicating these peptides are part of the body's natural feedback system for regulating hunger and feeding behavior.
Sakurai, T; Amemiya, A; Ishii, M; Matsuzaki, I; Chemelli, R M; Tanaka, H; Williams, S C; Richardson, J A; Kozlowski, G P; Wilson, S; Arch, J R; Buckingham, R E; Haynes, A C; Carr, S A; Annan, R S; McNulty, D E; Liu, W S; Terrett, J A; Elshourbagy, N A; Bergsma, D J; Yanagisawa, M · Original Research
Two Blood Pressure-Lowering Peptides From One Gene: Adrenomedullin and PAMP
Adrenomedullin and PAMP are co-produced from the same gene but lower blood pressure through distinct mechanisms (direct vascular vs. neural), and are expressed in diverse tissues with roles in cardiovascular, reproductive, and cancer biology.
Samson, W K · Review
How Fasting, Stress, and Somatostatin Change a Growth Hormone Peptide's Appetite Effect
KP-102 stimulated food intake in freely-fed but not fasted or stressed rats, and central somatostatin administration blocked this effect, demonstrating state-dependent appetite modulation by GH secretagogues.
Shibasaki, T; Yamauchi, N; Takeuchi, K; Ishii, S; Sugihara, H; Wakabayashi, I · Animal Study
Human Fetuses Already Have Working Growth Hormone Peptide Receptors
GHRP receptor mRNA was detected in human fetal pituitary by RT-PCR, and GHRP-2 stimulated dose-dependent GH release from cultured fetal pituitary cells, demonstrating functional GH secretagogue receptors are present before birth.
Shimon, I; Yan, X; Melmed, S · In Vitro
Measuring Opioid Peptides in Human Blood: Dynorphin B Is Stable but Dynorphin A Rapidly Degrades
Dynorphin B and beta-endorphin were confirmed in human plasma by HPLC and mass spectrometry, while dynorphin A was undetectable due to rapid enzymatic conversion to leu-enkephalin in blood.
Silberring, J; Li, Y M; Terenius, L; Nylander, I · In Vitro
Oral MK-677 Activates Bone Remodeling in Obese Young Men
MK-677 (25 mg/day for 8 weeks) increased bone formation markers more than resorption markers in 24 obese young males, with elevated IGF-1 levels suggesting a growth hormone-mediated anabolic bone effect.
Svensson, J; Ohlsson, C; Jansson, J O; Murphy, G; Wyss, D; Krupa, D; Cerchio, K; Polvino, W; Gertz, B; Baylink, D; Mohan, S; Bengtsson, B A · RCT
Oral MK-677 Increases Growth Hormone, Lean Mass, and Calorie Burning in Obese Men
MK-677 (25 mg/day for 8 weeks) increased 24-hour GH secretion rate by 1.8-fold, normalized pulsatile GH profiles, increased fat-free mass by ~3 kg, and raised basal metabolic rate in obese males.
Svensson, J; Lönn, L; Jansson, J O; Murphy, G; Wyss, D; Krupa, D; Cerchio, K; Polvino, W; Gertz, B; Boseaus, I; Sjöström, L; Bengtsson, B A · RCT
BNP Concentrations in the Fluid Around the Heart Track Heart Failure Severity
BNP concentrations in pericardial fluid were markedly elevated above plasma levels and closely associated with left ventricular dysfunction severity, supporting BNP's role as a local cardiac autocrine/paracrine factor.
Tanaka, T; Hasegawa, K; Fujita, M; Tamaki, S I; Yamazato, A; Kihara, Y; Nohara, R; Sasayama, S · Clinical Trial
How Electroacupuncture Triggers the Body's Natural Painkilling Peptides
Low-frequency (2 Hz) electroacupuncture activates endorphin/enkephalin systems (mu/delta receptors), while high-frequency (100 Hz) activates dynorphin systems (kappa receptors), with combined frequencies providing additive analgesia.
Ulett, G A; Han, S; Han, J S · Review
Growth Hormone Peptides and TRH Affect Leptin and Metabolism in Critically Ill Patients
GHRP-2 combined with TRH infusion reduced elevated leptin levels and reactivated suppressed GH and thyroid axes in prolonged critically ill patients, addressing the paradoxical fat-gain/muscle-wasting metabolic state.
Van den Berghe, G; Wouters, P; Carlsson, L; Baxter, R C; Bouillon, R; Bowers, C Y · RCT
Restoring Suppressed Hormones in ICU Patients With Growth Hormone and Thyroid Peptides
Combined GHRP-2 and TRH infusion most effectively reactivated both pulsatile GH secretion and the thyrotropic axis in 20 prolonged critically ill patients, with effects exceeding either agent alone.
Van den Berghe, G; de Zegher, F; Baxter, R C; Veldhuis, J D; Wouters, P; Schetz, M; Verwaest, C; Van der Vorst, E; Lauwers, P; Bouillon, R; Bowers, C Y · RCT
A New Opioid-Like Peptide Silences the Brain's Pain-Relief and Hormone Neurons
Orphanin FQ inhibited 68% of arcuate nucleus neurons, including beta-endorphin cells and neurosecretory neurons, through activation of inwardly-rectifying potassium conductance, providing a cellular mechanism for its anti-opioid effects.
Wagner, E J; Rønnekleiv, O K; Grandy, D K; Kelly, M J · Animal Study
Melanotan-II Triggered Erections in Men With Psychogenic Erectile Dysfunction
Melanotan-II, a synthetic cyclic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH), induced clinically apparent erections in 8 out of 10 men with psychogenic erectile dysfunction in a double-blind, placebo-controlled crossover trial. Men treated with Melanotan-II had an average of 38 minutes of tip rigidity above 80% — the threshold for penetrative intercourse — compared to just 3 minutes with placebo (p=0.0045). Side effects included nausea, yawning, stretching, and decreased appetite, but none required treatment. The effective dose was 0.025 mg/kg administered subcutaneously.
Wessells, H; Fuciarelli, K; Hansen, J; Hadley, M E; Hruby, V J; Dorr, R; Levine, N · Rct
Cerebrolysin: A Brain-Derived Peptide Preparation with Neurotrophic Properties and Clinical Evidence in Alzheimer's Disease
Cerebrolysin demonstrated dual neurotrophic and neuroprotective activity across multiple experimental models, promoting nerve cell growth in both peripheral and central nervous system neurons and protecting against various types of neuronal damage. In clinical trials with Alzheimer's disease patients, Cerebrolysin produced rapid improvement in overall patient state, particularly cognitive performance. Most notably, these improvements were long-lasting — detectable even 6 months after stopping treatment. This persistence suggests the drug may induce actual repair processes rather than simply providing temporary symptomatic relief. The drug showed extremely high tolerability with no reports of serious side effects, a significant advantage over natural neurotrophic factors which cause problems like hyperalgesia and weight loss.
Windisch, M; Gschanes, A; Hutter-Paier, B ·
Continuous Brain Infusion of GH Peptides Changes Which Genes Are Active in Key Neurons
Chronic central GH secretagogue infusion upregulated NPY and GHRH gene expression in the arcuate nucleus while altering Fos expression patterns, demonstrating neuroplastic adaptations to sustained receptor stimulation.
Bailey, A R; Giles, M; Brown, C H; Bull, P M; Macdonald, L P; Smith, L C; Smith, R G; Leng, G; Dickson, S L · Animal Study
The Brain's Feedback System Limits How Much Growth Hormone Peptides Can Activate Key Neurons
GHRH pretreatment and morphine both attenuated GH secretagogue-induced Fos expression in the arcuate nucleus, demonstrating negative feedback and opioid-GH system crosstalk in GH secretagogue signaling.
Bailey, A R; Honda, K; Smith, R G; Leng, G · Animal Study
Pituitary Tumors Express Growth Hormone Peptide Receptors That Can Release Hormones
GHS-R was expressed in 28 of 30 pituitary adenomas across all subtypes, not just GH-secreting tumors. Functional studies showed GH secretagogues stimulated hormone release from multiple tumor types in culture.
Barlier, A; Zamora, A J; Grino, M; Gunz, G; Pellegrini-Bouiller, I; Morange-Ramos, I; Figarella-Branger, D; Dufour, H; Jaquet, P; Enjalbert, A · In Vitro
How Scientists Map the 3D Structure of Antimicrobial Peptides in Membranes
Solid-state NMR studies showed antimicrobial peptides adopt amphipathic helical structures oriented parallel to bacterial membrane surfaces, providing a structural basis for their selective membrane disruption mechanism.
Bechinger, B · Review
Different Tissues Process the Opioid Precursor Prodynorphin Into Different Active Peptides
A prodynorphin processing enzyme was isolated and characterized, revealing tissue-specific processing that generates different bioactive dynorphin peptides in brain versus peripheral tissues like adrenal gland and gut.
Berman, Y; Ageyeva, L; Veksler, B; Wood, D; Devi, L A · In Vitro
Discovery of a Heart-Specific Receptor for Growth Hormone Peptides That Protects Against Heart Attack Damage
A novel cardiac-specific GHRP receptor distinct from the pituitary GHS-R was identified in rat heart tissue, binding hexarelin with high affinity and mediating cardioprotective effects independently of GH release.
Bodart, V; Bouchard, J F; McNicoll, N; Escher, E; Carrière, P; Ghigo, E; Sejlitz, T; Sirois, M G; Lamontagne, D; Ong, H · Animal Study
How to Properly Handle Blood Samples for Heart Failure Peptide Tests
BNP remained stable at room temperature for up to 72 hours without aprotinin, while ANP degraded significantly within hours. This stability makes BNP the most practical natriuretic peptide for routine clinical testing.
Buckley, M G; Marcus, N J; Yacoub, M H · In Vitro
A New Type of Blood Pressure Drug That Boosts Natriuretic Peptides While Blocking Angiotensin
Vasopeptidase inhibitors simultaneously increase natriuretic peptide levels (by blocking NEP) and decrease angiotensin II (by blocking ACE), producing superior blood pressure reduction compared to ACE inhibition alone.
Burnett, J C · Review