Search Educational Peptide Research

Retatrutide is an investigational GIP, GLP-1, and glucagon receptor agonist in Phase 3 development. Human trials report substantial effects on body weight and glucose control, with additional research in liver fat and obesity-related complications. It remains unapproved, and long-term cardiovascular outcomes, uncommon risks, maintenance after treatment, and real-world product quality remain unresolved.

Tesamorelin is an FDA-approved growth hormone-releasing hormone analogue for reducing excess abdominal fat in adults with HIV-associated lipodystrophy. Randomized trials support reduction of visceral adipose tissue in that specific population, with additional population-specific research on liver fat. It is not indicated for general weight loss, and evidence does not establish anti-aging, bodybuilding, cognitive, athletic, or longevity benefits.

Ipamorelin is a ghrelin-receptor agonist and growth-hormone secretagogue. Human research confirms that it can trigger an acute GH pulse, but the principal phase 2 clinical trial for postoperative ileus did not meet its primary efficacy endpoint. Evidence does not establish common claims involving sleep, recovery, body composition, or anti-aging, and FDA has highlighted serious safety and product-characterization concerns for compounded injectable use.

MOTS-C is a 16-amino-acid mitochondrial-derived peptide encoded within mitochondrial 12S rRNA, studied for metabolic-stress signaling, AMPK-related pathways, insulin sensitivity, exercise-related biology, and mitonuclear communication. It is not a component of an FDA-approved drug, and in July 2026 FDA proposed excluding MOTS-c free base and acetate from the 503A Bulks List over identity, effectiveness, safety, and immunogenicity concerns. Most therapeutic evidence remains preclinical; it is presented here as experimental, not as a proven human therapy.

Human chorionic gonadotropin (hCG) is a hormone that acts similarly to luteinizing hormone at the LH/hCG receptor. FDA-approved products exist for specific fertility and endocrine uses, while fitness or testosterone-support uses are outside the scope of MitoCore’s medical guidance. On this page, hCG is presented as an established hormone medication for certain indications, with clear warnings about supervision, fertility, estrogenic effects, and misuse.

GHK-Cu is the copper(II) complex of the tripeptide GHK. Research includes cell, animal, formulation, biomaterial, and limited topical human studies. The available topical human evidence does not establish broad anti-aging, hair-growth, or wound-treatment efficacy, and it cannot support systemic injectable claims. FDA separately identifies aggregation, peptide-impurity, immunogenicity, and limited-human-data concerns for compounded injectable GHK-Cu.

BPC-157 is an experimental 15-amino-acid peptide promoted for repair and gastrointestinal uses. Published human evidence consists of two tiny uncontrolled pilots and one retrospective private-clinic report; most mechanistic support remains preclinical. FDA has identified significant product-characterization, impurity, aggregation, immunogenicity, and long-term safety uncertainties.

TB-500 is marketed as the short thymosin-beta-4 fragment LKKTETQ and is not the same molecule as full-length 43-amino-acid thymosin beta-4. FDA reports no identified human exposure data for drug products containing the exact fragment. Human studies of full-length thymosin beta-4 and RGN-259 are related biological context only and do not establish TB-500 efficacy, safety, pharmacokinetics, or dosing.

KPV is the Lys-Pro-Val tripeptide at the C-terminus of alpha-MSH. It has been studied in intestinal cell systems and animal models of colitis and corneal injury, where researchers reported anti-inflammatory signaling and tissue-specific effects. FDA states that it has not identified human exposure data for KPV drug products, so KPV should be presented as a preclinical research peptide rather than a demonstrated human anti-inflammatory treatment.

NAD+ (nicotinamide adenine dinucleotide) is an essential cellular redox coenzyme, not a peptide. It participates in cellular energy metabolism and enzyme signaling -- including sirtuins, PARPs, and CD38-related pathways -- but the clinical effects of directly injecting or infusing NAD+ remain incompletely established. Evidence that precursors such as NR or NMN raise NAD-related biomarkers does not prove that direct NAD+ injection produces the same effects or meaningful health outcomes.

Elamipretide, also known by the development codes SS-31 and MTP-131, is a mitochondria-targeting tetrapeptide that binds cardiolipin in the inner mitochondrial membrane. In September 2025, FDA granted accelerated approval to the finished product Forzinity (elamipretide) for a narrow indication: improving muscle strength in adult and pediatric patients with genetically confirmed Barth syndrome weighing at least 30 kg, based on an intermediate endpoint. This approval does not extend to broader mitochondrial, anti-aging, exercise, cardiac, renal, neurologic, or ophthalmic uses.

AOD-9604 is a synthetic 16-amino-acid analogue of the human-growth-hormone 177-191 region with an added N-terminal tyrosine. Rodent studies reported lipolytic and weight-related effects, but the sponsor’s human obesity program failed its primary endpoint and was discontinued. FDA has also identified substantial characterization, route-specific safety, impurity, and immunogenicity uncertainties.

ACE-031 (ramatercept) is a soluble activin receptor type IIB–Fc fusion protein studied as a broad ligand trap intended to increase skeletal muscle mass. Small human studies documented pharmacodynamic effects, but the Duchenne muscular dystrophy program ended early after vascular-type adverse findings.

AHK-Cu is a copper complex of the tripeptide alanine-histidine-lysine. Direct evidence located for the compound is limited primarily to ex vivo human hair follicles and cultured dermal papilla cells; administered-human efficacy and systemic safety trials were not verified.

ARA-290, later developed as cibinetide, is an erythropoietin-derived peptide engineered to activate tissue-protective signaling without stimulating red-blood-cell production. Several small phase 2 studies evaluated neuropathic symptoms, corneal nerve measures, metabolic endpoints, and diabetic macular edema.

Adamax is a name used by research-peptide vendors for a modified Semax analogue, commonly described (in commercial/vendor material only) as approximately Ac-MEHFPGP-[adamantylated glycine]-NH2. No peer-reviewed pharmacology or therapeutic-efficacy study of exact Adamax was located, and its exact sequence/molecular formula has not been confirmed from an authoritative analytical or regulatory source -- these fields are left unconfirmed here rather than filled in from vendor material. Native Semax's separately documented evidence base does not transfer to Adamax, since chemical modifications change a peptide's pharmacology; the peer-reviewed P021 literature (a different CNTF-derived, adamantane-modified peptide) is likewise not evidence for Adamax and is noted here only because both molecules are described as carrying an adamantane-related modification -- this is structural/historical context, not shared efficacy evidence. Claimed advantages over Semax -- improved blood-brain-barrier penetration, longer half-life, greater BDNF induction, or better cognition, endurance, or recovery outcomes -- have no independent verified support.

Adipotide is a vascular-targeting proapoptotic peptidomimetic designed to bind prohibitin on white-adipose-tissue vasculature and deliver a mitochondria-disrupting sequence. Weight-loss findings come mainly from mouse and nonhuman-primate studies; a first-in-human trial was registered but terminated without verified published outcome results.

Afamelanotide is a synthetic melanocortin-1 receptor agonist with an FDA-approved controlled-release implant for adults with erythropoietic protoporphyria. Randomized trials support increased pain-free light exposure in that narrow indication. The approved implant, clinical monitoring, and manufacturing controls should not be equated with unregulated products marketed for cosmetic tanning.

Bremelanotide is the canonical identity of PT-141 and is an FDA-approved cyclic melanocortin agonist for a narrow HSDD indication. Earlier PT-141 studies and off-label discussions must remain separated from the approved use.

Bronchogen is an ultrashort synthetic peptide from the Khavinson bioregulator program, canonically sequenced as Ala-Glu-Asp-Leu (AEDL). It has been studied in DNA-interaction, gene-expression, and pulmonary preclinical models; no robust modern human efficacy program has been identified.

CJC-1295 with DAC is a long-acting GHRH analog engineered to form a covalent conjugate with circulating albumin. Small early human studies demonstrated prolonged increases in GH and IGF-1 and preserved GH pulsatility, but no approved indication or established clinical-benefit program followed. Current evidence is largely pharmacokinetic, pharmacodynamic, preclinical, and regulatory rather than outcome-based.

Cagrilintide is a long-acting amylin analog studied for weight management, both alone and combined with semaglutide (as CagriSema). It mimics the satiety hormone amylin to reduce food intake, and has shown meaningful weight loss in completed Phase 2 and Phase 3 human trials.

Cardiogen is a synthetic tetrapeptide commonly identified as Ala-Glu-Asp-Arg (AEDR). The direct literature located is preclinical, including rat myocardial tissue culture, biochemical assays, and a rat tumor model; no controlled human administration study was verified.

Cerebrolysin is a proprietary porcine-brain-derived mixture of low-molecular-weight peptides and free amino acids studied in stroke, traumatic brain injury, and dementia. Human trials exist, but results are mixed and indication-specific.

Chonluten is commonly described as the tripeptide Glu-Asp-Gly (EDG). It has been studied for inflammatory/proliferative signaling in immune-cell models and appears in respiratory-bioregulator literature, but clinical benefit claims remain weakly supported.

Copper-free GHK (glycyl-L-histidyl-L-lysine) is the tripeptide form of GHK without a complexed copper ion, chemically distinct from GHK-Cu (the copper(II)-complexed form more commonly sold and studied for skin/wound-healing research). Direct copper-free GHK research includes a 2012 stem-cell-recovery skin study (PMID 23019153), gene-expression work relevant to nervous-system function and cognitive decline (PMID 28212278), a 2015 review of GHK's role in skin-regeneration cellular pathways (PMID 26236730), and a 2025 review of topical anti-wrinkle use (PMID 39963574). This is topical and cell-culture evidence; it does not establish injectable or systemic benefit. The larger GHK-Cu wound-healing/collagen literature does not automatically transfer to copper-free GHK, and copper-delivery-related claims do not apply to copper-free material without demonstrated copper-complexing in the specific product used.

Cortagen is a synthetic tetrapeptide identified as Ala-Glu-Asp-Pro (AEDP), developed from research on the distinct brain-cortex extract Cortexin. Its direct evidence is preclinical, including rodent nerve-injury, ischemia, and gene-expression studies.

Crystagen is a short peptide bioregulator generally identified in peer-reviewed literature as the tripeptide Glu-Asp-Pro (EDP). It has been studied mainly in cell, tissue, and animal immune models.

Dermorphin is a potent opioid-receptor-active peptide first isolated from frog skin. Limited older human experiments exist, but modern safety, product-quality, and therapeutic evidence are inadequate.

Dihexa is a metabolically stabilized angiotensin-IV-derived peptidomimetic studied for HGF/c-Met potentiation and synaptogenic effects. Evidence remains preclinical.

Dulaglutide is a long-acting GLP-1 receptor agonist fusion protein, FDA-approved as the branded finished product Trulicity for type 2 diabetes glycemic control and cardiovascular risk reduction. FDA approval applies strictly to the Trulicity finished product -- it does not extend to unapproved vendor, research, or lyophilized dulaglutide material, which is a distinct regulatory and quality category. Dulaglutide/Trulicity does not carry an FDA-approved obesity indication, and semaglutide/tirzepatide outcomes must not be assumed to transfer to it.

FOXO4-DRI is an experimental D-retro-inverso peptide designed to disrupt the FOXO4-p53 interaction in senescent cells. Cell and mouse studies show senolytic activity in selected models, but no human therapeutic or safety evidence has been established.

Follistatin-344 (FS344) is an alternatively spliced follistatin precursor isoform. Its clinical evidence comes from AAV-mediated gene therapy (AAV1.CMV.FS344) in small trials for Becker muscular dystrophy and sporadic inclusion body myositis -- an approach that drives sustained endogenous follistatin expression, not an injected recombinant protein. A commercial vendor vial labeled "Follistatin-344" is not automatically equivalent to this gene-therapy construct, to the processed FS315 circulating isoform, to FS288, to generic follistatin, to myostatin, or to ACE-031.

GHRP-2, also called pralmorelin, is a synthetic ghrelin-receptor agonist that stimulates GH release and can also affect appetite, prolactin, ACTH, and cortisol. Japan uses pralmorelin as a diagnostic stimulus for GH deficiency, while U.S. FDA materials identify safety and product-quality concerns for compounded injectable and nasal GHRP-2. Human evidence supports endocrine and diagnostic effects, not broad wellness outcomes.

GHRP-6 is a synthetic ghrelin-receptor agonist and early growth-hormone-releasing hexapeptide. Human studies demonstrate acute GH stimulation, oral activity in selected settings, diagnostic research, and pharmacokinetics, while much of the tissue-protection and recovery literature is preclinical. No approved therapeutic indication or adequate long-term safety program exists.

Gonadorelin acetate is a synthetic GnRH salt studied and historically used in pulsatile reproductive-endocrine therapy and diagnostic stimulation testing.

HGH Fragment 176-191 is the unmodified C-terminal 16-amino-acid segment of human growth hormone. It is frequently confused with AOD-9604, but the two are different molecular entities.

HMG usually refers to menotropins, a purified urinary-derived gonadotropin preparation containing FSH and LH activity. It has established fertility-medicine use, while broader or male-use claims require separate evidence and regulatory context.

Hexarelin, also called examorelin, is a synthetic growth-hormone secretagogue and ghrelin-receptor agonist. Small human studies documented strong acute GH release, accompanying prolactin/ACTH/cortisol responses, and short-lived cardiovascular effects. Longer-term cardioprotection and anti-fibrotic findings are primarily preclinical, so they should not be presented as established human benefits.

IGF-1 DES (Des(1-3)-IGF-I) is native IGF-I with its first three N-terminal amino acids removed, which reduces binding to several IGF-binding proteins and increases bioactive potency in cell and animal studies. It is a distinct molecule from Long R3 IGF-I, native IGF-I/mecasermin, MGF, and PEG-MGF, and no verified controlled human administration trial was identified.

Kisspeptin-10 is a short active kisspeptin fragment studied as a probe and potential modulator of the human reproductive axis. Direct human administration studies are small and indication-specific.

LL-37 is the 37-amino-acid active human cathelicidin host-defense peptide. Human topical wound trials have evaluated LL-37 formulations, while mechanistic research shows antimicrobial, wound-healing, and context-dependent inflammatory activity. These topical data do not establish safety or efficacy for systemic or injectable use.

Liraglutide is a once-daily GLP-1 receptor agonist available in FDA-approved product-specific forms. Saxenda is approved for chronic weight management in qualifying adults and adolescents, while Victoza is approved for type 2 diabetes and cardiovascular-risk reduction in a defined adult diabetes population.

Long R3 IGF-I is an engineered analogue of insulin-like growth factor I developed largely for experimental and cell-culture applications. The audited evidence is predominantly animal and cell based; no verified controlled human administration trial was identified.

Mechano Growth Factor E-peptide (MGF E-peptide, commonly shortened to "MGF") is a synthetic peptide corresponding to the E-domain of IGF-1Ec, the mechanically responsive splice-isoform/propeptide transcript of IGF-1. IGF-1Ec is the parent splice-isoform context this synthetic peptide is derived from -- not an alternate name for the same molecule -- and endogenous IGF-1Ec expression studies (measuring gene expression after exercise or mechanical loading) are evidence about the body's own transcript biology, not about administering the synthetic E-peptide. Direct synthetic-MGF-E-peptide cell/animal studies exist separately and may support exact-compound mechanistic/preclinical claims, but no adequate human therapeutic trial establishes synthetic MGF for muscle gain, recovery, anti-aging, or injury repair. PEG-MGF is a separate PEGylated entity and is not evidence for unmodified MGF E-peptide, or vice versa.

Melanotan II is an investigational cyclic melanocortin agonist with small early human studies and multiple safety case reports. It remains on publication hold.

N-Acetyl Epitalon Amidate (Ac-AEDG-NH2) is a commercially described N-terminally acetylated, C-terminally amidated analogue of AEDG (Epitalon/Epithalon). No direct indexed therapeutic study of the exact modified molecule has been identified; evidence for the parent peptide Epitalon/AEDG does not transfer to this distinct chemical entity.

N-Acetyl Selank Amidate (commonly represented as Ac-Thr-Lys-Pro-Arg-Pro-Gly-Pro-NH2) is a chemically modified Selank analogue, distinct from native Selank. No direct PubMed-indexed therapeutic study of this exact doubly modified compound was located. Native Selank, Selank acetate, and tuftsin studies are not direct evidence for this analogue -- Selank's regulatory/clinical history in its country of origin does not transfer either. Claims of improved stability, half-life, blood-brain-barrier penetration, or preserved pharmacology relative to native Selank remain hypotheses without direct supporting data on the exact compound.

N-Acetyl Semax Amidate (commonly represented as Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2) is a doubly modified Semax analogue -- N-terminally acetylated and C-terminally amidated -- distinct from native Semax. A 2016 study (PMID 27586814) examined N-terminally acetylated Semax ("Ac-Semax") chemistry and showed that N-terminal acetylation changes Semax's chemical/biological behavior; that paper is evidence about acetylated-Semax chemistry only and is not automatically evidence for this additionally C-terminally amidated product, since the exact molecule studied has not been independently confirmed to match the commercial doubly modified compound. Native Semax's human/animal/BDNF/ischemia/dopamine evidence does not transfer to this analogue. No exact-compound human efficacy or safety study was identified. Claims of enhanced half-life or blood-brain-barrier penetration require direct pharmacokinetic evidence on the exact compound, which does not currently exist.

Orexin A, also called hypocretin-1, is an endogenous wake-regulating neuropeptide. Small pilot studies tested intranasal administration in narcolepsy and in healthy volunteers; a 2022 pilot study found a measurable sympathetic-nervous-system effect. This remains investigational.

Orexin B, also called hypocretin-2, is a native 28-amino-acid hypothalamic neuropeptide involved in orexin-receptor signaling. Evidence for native Orexin B consists primarily of receptor, structural, cellular, and animal research. No verified direct human administration trial establishes native Orexin B efficacy, safety, pharmacokinetics, or dosing.

Ovagen is listed in the short-peptide gene-regulation literature as the tripeptide Glu-Asp-Leu (EDL). Despite its name, the indexed literature associates it with renal-cell aging and hepatoprotection research, not ovarian or reproductive biology; direct exact-compound evidence remains sparse.

Oxytocin is an endogenous peptide hormone and an established obstetric medicine. Strong evidence for uterotonic use should not be generalized to intranasal, behavioral, bonding, bodybuilding, or wellness claims.

P021 is a CNTF (ciliary neurotrophic factor)-derived small-molecule peptide mimetic that incorporates an adamantane-related structural modification. Peer-reviewed mouse and cell studies report effects on neurogenesis, synaptic and dendritic structure, tau and amyloid-beta pathology, and cognitive/memory measures in Alzheimer's-disease and CDKL5-deficiency models. These findings do not establish Alzheimer's prevention or treatment in humans, and a 2024 CDKL5-model study found P021 improved cellular measures but failed to raise BDNF or improve neuroanatomical defects in vivo -- illustrating limited translation from favorable cell-level effects to whole-animal outcomes. Commercially sold "P21" or "P21-adamantane" products have not been independently confirmed to be chemically identical to this peer-reviewed entity; this page treats the peer-reviewed P021 literature as describing this specific CNTF-mimetic molecule and does not extend it to any unverified commercial product without further identity confirmation.

PE-22-28 is a seven-amino-acid fragment derived from the spadin research program and studied as a TREK-1 potassium-channel inhibitor. The evidence located is preclinical only.

PEG-MGF is a poorly standardized term for a pegylated synthetic peptide related to the mechano growth factor E-domain. It is not the same as endogenous IGF-1Ec, full-length MGF, ordinary IGF-1, or Long R3 IGF-I.

PNC-27 is a chimeric 32-residue experimental anticancer peptide studied for its ability to bind membrane-associated HDM-2/MDM2 on cancer cells and trigger targeted cell lysis. Evidence is limited to in-vitro, ex-vivo, and animal cancer models; no human clinical efficacy has been established.

PTD-DBM is a protein-transduction-domain-linked Dishevelled-binding-motif competitor peptide designed to disrupt the CXXC5-Dishevelled interaction and modulate Wnt/beta-catenin signaling. Preclinical mouse studies report hair-regeneration effects, including stimulation of hair regrowth and wound-induced hair neogenesis (PMID 28595998) and a role for CXXC5 in DHT/PGD2-driven androgenetic alopecia (PMID 36831222); a 2025 review situates this within the broader Wnt/beta-catenin hair-follicle-neogenesis literature (PMID 40497955). These are preclinical mouse-model findings, not evidence of human efficacy, and DHT/PGD2 androgenetic-alopecia models do not by themselves establish a treatment effect in people. Wnt-pathway activation is not universally beneficial and carries theoretical pathway-risk considerations that preclinical hair-focused studies do not address. No adequate human randomized therapeutic trial was identified, and no injectable or systemic dosing can be inferred from this topical/preclinical work.

Palmitoyl Pentapeptide-4 -- commercially known under the Matrixyl family of trade names, historically also called palmitoyl pentapeptide-3 in some literature -- has human topical cosmetic research support for photoaged skin and wrinkles, including a 2005 study on photoaged facial skin (PMID 18492182) and a 2023 double-blind randomized trial on crow's-feet wrinkles (PMID 36909866, alongside acetylhexapeptide-3). This evidence is specific to topical application; route and formulation are integral to it, and it cannot support injectable or systemic anti-aging, systemic collagen-increase, muscle-growth, or other systemic regenerative claims. Multi-active cosmetic formulations tested alongside other ingredients cannot have their effects attributed solely to this peptide unless a study specifically isolates it. "Matrixyl" is a commercial/brand family name and is not automatically identical to palmitoyl pentapeptide-4 in every product sold under that name; this page treats palmitoyl pentapeptide-4 as the specific molecule its cited evidence supports.

Pancragen is a short peptide bioregulator described in the indexed literature as the tetrapeptide Lys-Glu-Asp-Trp (KEDW). It has been studied mainly in pancreatic cell, animal, and non-human-primate metabolic models.

Pinealon is a short tripeptide commonly identified as Glu-Asp-Arg (EDR). Most direct evidence is preclinical and comes from a narrow, frequently Russian-language research lineage.

Prostamax is a short synthetic peptide in the Khavinson bioregulator lineage, confirmed by patent RU2177802C1 as the tetrapeptide Lys-Glu-Asp-Pro (KEDP). It has been studied for chromatin effects and in experimental prostatitis/BPH animal models; it must not be confused with Prostatilen or other prostate tissue extracts.

SLU-PP-332 is an experimental small-molecule ERR agonist with mouse and cell evidence related to oxidative metabolism, endurance, metabolic syndrome, kidney aging, and heart failure models. In vitro metabolism and analytical-chemistry studies (including doping-control-oriented work) have characterized SLU-PP-332 and the related, distinct compound SLU-PP-915 using human liver fractions -- laboratory material, not human administration.

Selank is a synthetic peptide-based compound often discussed for stress response, anxiety, and neuroprotective mechanisms. It has more regional history of use than many gray-market peptides, but U.S.-style FDA-approved indications for common anxiolytic claims are lacking. This page summarizes Selank's regulatory status, small/limited human evidence, preclinical findings, and anecdotal nootropic reports.

Semaglutide is a GLP-1 receptor agonist FDA-approved under three brand names (Ozempic, Wegovy, Rybelsus) for type 2 diabetes and/or chronic weight management, with the largest published trial program of any current obesity medication.

Semax is a synthetic peptide-based compound often discussed for focus, cognition, and neuroprotective mechanisms. It has more regional history of use than many gray-market peptides, but U.S.-style FDA-approved indications for common nootropic claims are lacking. This page summarizes Semax's regulatory status, small/limited human evidence, preclinical findings, and anecdotal nootropic reports.

Sermorelin is the amidated 1–29 fragment of human growth hormone–releasing hormone. Historical human studies and former U.S. approvals support its ability to stimulate pituitary growth-hormone release and, in selected pediatric growth-hormone-deficiency populations, promote growth. Evidence for modern adult wellness, anti-aging, recovery, or body-composition uses remains limited and should not be inferred from the former pediatric and diagnostic indications.

Somatropin is a recombinant form of human growth hormone, FDA-approved since the 1980s-2000s (multiple brands) for pediatric and adult growth hormone deficiency and several related conditions. It has one of the largest human clinical evidence bases of any compound in this catalog, but off-label wellness/anti-aging use is not supported by the same evidence and carries an open, FDA-flagged safety question about long-term mortality risk in a specific pediatric population.

Survodutide is an investigational dual agonist that activates both the glucagon receptor and the GLP-1 receptor, combining GLP-1-driven appetite suppression with glucagon-driven energy expenditure. It is in Phase 3 development for obesity and type 2 diabetes, and separately for MASH (metabolic dysfunction-associated steatohepatitis) with liver fibrosis.

Teriparatide is recombinant human parathyroid hormone 1-34 (PTH(1-34)), FDA-approved in multiple finished products, including Forteo, for defined osteoporosis populations at high risk of fracture. It is distinct from full-length PTH(1-84) and from abaloparatide.

Testagen is the tetrapeptide Lys-Glu-Asp-Gly (KEDG), studied for cellular/nuclear penetration and older endocrine/reproductive preclinical literature. Its name should not be interpreted as evidence it raises testosterone.

Thymalin is described in the literature as a polypeptide extract or complex isolated from calf thymus, not a single defined peptide sequence. Cell studies and several small or observational human reports exist, but product composition, study quality, and independent replication limit confidence.

Thymosin alpha 1, or thymalfasin, is a defined immunomodulatory peptide studied in viral hepatitis, sepsis, pancreatitis, cancer, and other settings. Results are indication-specific and mixed.

Tirzepatide is a dual GIP/GLP-1 receptor agonist approved as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management and moderate-to-severe obstructive sleep apnea in adults with obesity. Large phase 3 programs, including SURMOUNT and SURPASS, support its approved metabolic indications.

VIP is a long-studied endogenous neuropeptide with broad vascular, pulmonary, gastrointestinal, neural, and immune effects. Human aviptadil trials are indication- and route-specific and have produced mixed results: a 2025 phase II trial of inhaled aviptadil in hospitalized COVID-19 pneumonia reported a borderline-shorter mean time to discharge, lower day-7 dyspnea, and greater day-28 CT improvement (mortality numerically lower but not statistically significant), while intravenous aviptadil showed no benefit in the large TESICO critical-COVID-19 trial.