Steadfast Research Group Research Blog
Plain-language explainers on peptide research, quality verification, and laboratory practices — sourced, dated, and reviewed.
What Has Published Research Reported About Dihexa?
Dihexa is a synthetic angiotensin IV analog (C27H44N4O5). Its key 2012 and 2014 mechanism papers were retracted in 2025, leaving the evidence unsettled.
What Has Published Research Reported About Semax?
Semax is a synthetic ACTH(4-7)-Pro-Gly-Pro heptapeptide. Studies reported BDNF, monoamine and ischemia-model gene-expression changes in rodents.
What Has Published Research Reported About Selank?
Selank is a seven-residue tuftsin analog. Studies reported enkephalinase inhibition, rodent gene-expression shifts and mixed GABA-related cell data.
What Has Published Research Reported About Melanotan II?
Melanotan II is a cyclic heptapeptide alpha-MSH analog. Studies reported broad melanocortin agonism, rodent feeding findings and purity gaps in vials.
What Has Published Research Reported About PT-141?
PT-141 (bremelanotide) is a cyclic heptapeptide alpha-MSH analog. Studies reported melanocortin receptor agonism and rat and primate behavioral findings.
What Has Published Research Reported About MK-677?
MK-677 is an oral, nonpeptide GH secretagogue reported in 1995. Studies described GH release distinct from GHRH and raised IGF-I in dogs and humans.
What Has Published Research Reported About GHRP-6?
GHRP-6 is a synthetic hexapeptide reported in 1984. Studies described GH release at pituitary and hypothalamic sites and synergy with GHRH.
What Has Published Research Reported About GHRP-2?
GHRP-2 (pralmorelin, KP-102) is a synthetic hexapeptide. Studies reported GH release in ovine cells, rats and dogs, and a 2007 diagnostic test.
What Has Published Research Reported About Hexarelin?
Hexarelin is a GHRP-6 analog with a 2-methyl D-tryptophan. 1990s studies reported GH release in rats and volunteers; later cardiac work identified CD36.
What Has Published Research Reported About Tesamorelin?
Tesamorelin is GHRH(1-44) with a hexenoyl group on its N-terminal tyrosine. A 2007 paper reported DPP-IV resistance; trials measured visceral fat by CT.
What Has Published Research Reported About Sermorelin?
Sermorelin is GHRH(1-29)-NH2; a 1984 study reported about half of native GHRH's in vitro potency, and a 1989 study found plasma DPP-IV cleaved it rapidly.
What Has Published Research Reported About CJC-1295?
CJC-1295 is an albumin-binding GHRH(1-29) analog; 2006 studies estimated a 5.8 to 8.1 day half-life and reported IGF-I rises lasting 9 to 11 days.
What Has Published Research Reported About Ipamorelin?
Ipamorelin is a synthetic pentapeptide ghrelin (GHS) receptor agonist; a 1998 study reported GH release without ACTH or cortisol rises in swine.
What Has Research Described About Cagrilintide?
Cagrilintide is a lipidated, long-acting amylin analogue that activates amylin and calcitonin receptors; trials reported a half-life of 159 to 195 hours.
Semaglutide Mechanism of Action: What Research Reports
Research links semaglutide to GLP-1 receptor activation: higher insulin secretion, lower glucagon, slower early gastric emptying and brain signaling.
GHK-Cu Mechanism of Action: What Research Proposes
Studies proposed GHK-Cu acts via copper exchange, matrix remodeling, growth-factor and integrin signals, and antioxidant chemistry in lab models.
Thymosin Beta-4 and Actin: What Research Reports
Studies described thymosin beta-4 as a G-actin sequestering peptide that favored ATP-actin and passed monomers to profilin for filament growth in vitro.
TB-500 Mechanism of Action: What Research Proposes
Studies have proposed thymosin beta-4 mechanisms: G-actin sequestration, ILK/Akt signaling, NF-kB suppression and Ac-SDKP release, in preclinical models.
GLP-1 Receptor Agonists: What the Research Describes
GLP-1 receptor agonists are engineered analogues of a 30-amino-acid gut hormone; reported half-lives run from minutes to 46.1 hours in mini-pigs.
Tirzepatide Preclinical Studies: What Research Reports
Preclinical tirzepatide studies reported 0.135 nM GIP receptor affinity vs 4.23 nM at GLP-1R, plus rodent food-intake, adipose and emesis findings.
Semaglutide vs Tirzepatide: What the Literature Shows
Semaglutide is a selective GLP-1 receptor agonist; tirzepatide is a dual GIP/GLP-1 agonist built on GIP. Backbone, acyl chain and half-life differ.
Tirzepatide's Dual GIP/GLP-1 Receptor Mechanism
Published pharmacology describes tirzepatide as an imbalanced dual agonist favouring the GIP receptor, and as cAMP-biased at the GLP-1 receptor.
What Does Research Say About Tirzepatide?
Tirzepatide (LY3298176) is a 39-amino-acid dual GIP and GLP-1 receptor agonist whose discovery paper reported a mean half-life near five days.
What Does Research Say About Retatrutide?
Retatrutide (LY3437943) is an investigational triple GIP, GLP-1 and glucagon receptor agonist studied from a 2022 discovery paper through phase 3.
What Has Research Shown About BPC-157 and Angiogenesis?
BPC-157 angiogenesis research is preclinical: chick membrane, tube-formation and rat hind-limb ischaemia models reported increased vessel density.
What Has Research Reported on BPC-157 in the Gut?
BPC-157 gut research is preclinical: rat studies reported fewer gastric, duodenal and colonic lesions, closed fistulas and short-bowel weight gain.
What Does Research Show on BPC-157 and Tendons?
Rat Achilles and ligament transection studies reported faster recovery with BPC-157, but the tendon evidence remains preclinical, not human.
What Mechanisms Has Research Proposed for BPC-157?
Preclinical studies have proposed several overlapping pathways for BPC-157: VEGFR2, nitric oxide, FAK-paxillin, growth hormone receptor and EGR-1.
How Researchers Verify Peptide Quality Before Use
Researchers verify a peptide by matching the COA to the vial lot, confirming identity by mass spectrometry, reading HPLC purity, and checking net content.
What Does Research Say About Semaglutide?
Published research describes semaglutide as a GLP-1 analogue with Aib8 and Arg34 substitutions and a C18 diacid chain acylated at lysine 26.
Domestic vs Overseas Research Peptide Sourcing
Domestic and overseas peptide sourcing differ on four axes: batch documentation, transit conditions, import exposure, and recourse when a batch fails.
What Is Lyophilization and Why Are Peptides Freeze-Dried?
Lyophilization is vacuum sublimation of ice from frozen peptide solution, removing the water that drives hydrolysis, deamidation and aggregation.
Why Independent Third-Party Peptide Testing Matters
Independent testing matters because purity is a per-batch measurement: outside labs measured 7.7-14.37% purity in online peptide vials labelled 99% pure.
What Does Research Say About GHK-Cu?
GHK-Cu research spans 50+ years: fibroblast, rodent, and gene-expression studies observed effects on collagen, matrix remodeling, and oxidative markers.
Red Flags to Watch For When Sourcing Research Peptides
The biggest red flags in peptide sourcing: no batch-specific COA, purity claimed without a named method or lab, static lot numbers, and outcome marketing.
How Mass Spectrometry Verifies a Peptide's Identity
How mass spectrometry confirms a research peptide's identity: measured mass versus theoretical mass, ESI and MALDI, tandem sequencing, and why mass is not purity.
How Peptide Concentration Is Calculated When Reconstituting
Concentration equals net peptide mass divided by solvent volume (mg/mL). Counterions and residual water mean net mass is below the vial's label weight.
How to Spot a Fake or Altered Peptide COA
How researchers detect a fake or altered peptide Certificate of Analysis: lot matching, named testing lab, real HPLC and mass-spec data, dates, and chromatograms.
How Are Research Peptides Reconstituted in the Lab?
Laboratory procedure for reconstituting lyophilized research peptides: solvent choice (bacteriostatic vs sterile water), concentration math in mg/mL, and stability.
How Should Research Peptides Be Stored?
Lyophilized research peptides are kept cold, dry, and dark: refrigerated short term, frozen at -20°C or -80°C long term; reconstituted vials held at 2–8°C.
How to Evaluate a Research Peptide Supplier
How researchers evaluate a research peptide supplier: independent third-party testing, lot-specific COAs, purity documentation, transparency, handling, and honest research-use-only framing.
How to Read a Peptide Certificate of Analysis
A plain-language guide to reading a peptide Certificate of Analysis: identity, purity, HPLC, mass spectrometry, lot matching, and red flags.
What Are Research Peptides and How Are They Studied?
A plain-language explainer on research peptides: what a peptide is, what research-use-only means, how peptides are studied in vitro and in preclinical models, and why purity and COAs matter.
What Does Research Say About BPC-157?
A research-framed profile of BPC-157: what preclinical rodent and in-vitro studies observed in tendon, ligament, gut, and angiogenesis models, and why the evidence is preclinical.
What Research Says About TB-500 (Thymosin Beta-4)
Published TB-500 research is largely preclinical: thymosin beta-4 studies examined actin binding, cell migration, and tissue repair in animal models.
What Does 'Research Use Only' Mean for Peptides?
What 'for research use only' means for peptides: an intended-use designation for laboratory materials, distinct from approved drugs and dietary supplements.
What Is Bacteriostatic Water for Peptide Reconstitution?
Bacteriostatic water is sterile water with about 0.9% benzyl alcohol, a preservative that lets a vial serve multiple research reconstitutions.
What Is HPLC and How Does It Test Peptide Purity?
What HPLC is and how reversed-phase HPLC measures peptide purity: columns, gradients, UV detection at 214 nm, chromatogram peak-area percent, and the COA.
What Is Peptide Purity and Why Does It Matter?
Peptide purity is the percent of a sample that is the target peptide, measured by HPLC. It matters because impurities can distort research results.