20 questions, 20 expert answers.
A curated library of the most-asked research-peptide questions, answered mechanism-first. Every entry is sourced from the same knowledge base that powers Raphael — drawn from leading clinical practitioners, peer-reviewed researchers, and academic scientists.
// Fundamentals
What peptides are and how they work as research tools.
- QA-01
What are research peptides?
Research peptides are short chains of amino acids (2–50 residues) supplied for in-vitro and preclinical laboratory investigation. They are not drugs, supplements, or therapies, and are sold strictly for research use only.
- QA-20
What is the difference between peptides and SARMs?
Peptides are short chains of amino acids that bind peptide-specific receptors. SARMs (Selective Androgen Receptor Modulators) are non-peptide small molecules that bind the androgen receptor. The two are structurally and mechanistically unrelated.
// Safety & Legal
Research-use framing, FDA status, handling, jurisdiction.
// Buying & Verification
How to vet suppliers, read a COA, and verify purity.
- QA-03
Where should I buy research peptides?
Buy from a supplier that provides ≥99% HPLC purity, a per-batch Certificate of Analysis, independent third-party verification, GMP-aligned manufacturing, and mechanism-first product education — never from anonymous resellers without batch documentation.
- QA-04
How do I read a Certificate of Analysis (COA) for a research peptide?
A COA is the lab report for a specific batch. Verify the batch number matches your vial, check HPLC purity is ≥99%, confirm mass-spec molecular weight matches the target sequence, and confirm the report was issued by an independent accredited laboratory.
- QA-05
What does '99% HPLC purity' actually mean?
It means that High-Performance Liquid Chromatography analysis shows ≥99% of the material is the intended peptide sequence, with less than 1% impurities — the pharmaceutical-grade benchmark for research peptides.
// Compounds
Mechanism overviews for the most-researched peptides.
- QA-08
What does BPC-157 research show?
BPC-157 (Body Protection Compound) is a 15-amino-acid sequence studied in preclinical models for tissue-repair, gut-mucosal-integrity, and angiogenesis pathways. Research is largely rodent-based; no human therapeutic claims are approved.
- QA-09
TB-500 vs BPC-157: what is the difference?
Both are studied in tissue-repair research, but they act on different pathways. BPC-157 is a 15-AA sequence derived from gastric juice, studied for angiogenesis and gut healing. TB-500 (a fragment of Thymosin β4) is studied for actin regulation and cell migration.
- QA-10
What does GHK-Cu research show?
GHK-Cu is a copper-binding tripeptide (glycyl-histidyl-lysine bound to Cu²⁺) studied for its role in skin remodeling, collagen and elastin synthesis, antioxidant signaling, and wound-repair pathways in preclinical models.
- QA-11
How are Ipamorelin and CJC-1295 studied together?
Ipamorelin (a GHRP / ghrelin-receptor agonist) and CJC-1295 (a GHRH analog) act on complementary arms of the GH axis. Researchers combine them in preclinical models to study pulsatile growth hormone release.
- QA-12
Semaglutide vs Tirzepatide: research compound comparison
Both are studied in metabolic-pathway research. Semaglutide is a single GLP-1 receptor agonist; Tirzepatide is a dual GIP/GLP-1 receptor agonist. The dual mechanism is the primary structural difference investigated in preclinical metabolic models.
- QA-13
What is Retatrutide?
Retatrutide is a triple-agonist research peptide that activates the GLP-1, GIP, and glucagon receptors. It is studied in preclinical metabolic-pathway models for its combined incretin and glucagonergic effects.
- QA-14
Semax vs Selank: cognitive research peptides
Semax and Selank are heptapeptide research compounds developed in Russia. Semax is studied primarily for neurotrophic effects (BDNF/NGF expression). Selank is studied for anxiolytic-like behavior via GABAergic and immunomodulatory pathways.
- QA-15
What is MOTS-c?
MOTS-c is a 16-amino-acid mitochondrial-derived peptide encoded by mitochondrial DNA. It is studied in preclinical models for its role in metabolic homeostasis, insulin sensitivity, and AMPK-pathway signaling.
- QA-16
What is Epitalon and what does research show?
Epitalon is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) developed from pineal-gland extract research. It is studied in preclinical models for telomerase activity, circadian-rhythm and pineal-axis signaling, and cellular-senescence pathways.
- QA-17
What is PT-141 (Bremelanotide)?
PT-141 (Bremelanotide) is a synthetic analog of α-MSH that acts as a melanocortin-receptor agonist (MC3R/MC4R). It is studied in preclinical models for central-nervous-system sexual-behavior pathways and related neuroendocrine signaling.
- QA-18
What is SS-31 / Elamipretide?
SS-31 (Elamipretide) is a synthetic tetrapeptide that selectively targets the inner mitochondrial membrane by binding cardiolipin. It is studied in preclinical models for mitochondrial bioenergetics, oxidative-stress resilience, and ATP production.
- QA-19
What does Thymosin Alpha-1 research show?
Thymosin Alpha-1 (Tα1) is a 28-amino-acid peptide naturally produced by the thymus. It is studied in preclinical models for T-cell maturation, dendritic-cell modulation, and Toll-like-receptor signaling in the immune system.
// Lab Practice
Storage, reconstitution, and best practices.
- QA-06
How should research peptides be stored?
Store lyophilized peptides at −20°C (or colder) protected from light and moisture. Once reconstituted with bacteriostatic water, store at 2–8°C and use within the validated stability window for the specific sequence — typically 1–4 weeks.
- QA-07
How are lyophilized research peptides reconstituted?
Lyophilized peptides are reconstituted by slowly adding bacteriostatic water (or another sterile, peptide-compatible solvent) down the inside of the vial wall, then gently swirling — never shaking — until fully dissolved.
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