What Are Research Peptides? A Complete Guide
Summary: Research peptides are short chains of 2–50 amino acids made by solid-phase peptide synthesis for laboratory research. This guide covers how they are made, purity testing, categories, supplier evaluation, and cited science profiles with published study doses and lab handling.
Peptide Science Profiles
Literature values for laboratory reference only — not dosing guidance.
Published Study Dosing Chart
| Peptide | Study model | Dose | Route & frequency | Duration | Source |
|---|---|---|---|---|---|
| BPC-157 | Rat, transected Achilles tendon | 10 µg/kg, 10 ng/kg or 10 pg/kg | Intraperitoneal, once daily | Up to 14 days | Staresinic M 2003 |
| Semaglutide | Human, adults with overweight/obesity (STEP 1, n=1,961) | 2.4 mg | Subcutaneous, once weekly | 68 weeks | Wilding JPH 2021 |
| Tirzepatide | Human, adults with obesity (SURMOUNT-1) | 5 mg, 10 mg or 15 mg | Subcutaneous, once weekly | 72 weeks | Jastreboff AM 2022 |
| Retatrutide | Human, adults with obesity (Phase 2) | 1, 4, 8 or 12 mg (escalated from 2 or 4 mg) | Subcutaneous, once weekly | 48 weeks | Jastreboff AM 2023 |
| Ipamorelin | Primary rat pituitary cells | EC50 1.3 nmol/L | In vitro | Acute | Raun K 1998 |
| Ipamorelin | Conscious swine | ED50 2.3 nmol/kg | Intravenous | Single dose | Raun K 1998 |
| CJC-1295 w/DAC | Human, healthy adults 21–61 yr | Ascending single doses; best tolerated at 30 or 60 µg/kg | Subcutaneous, single or weekly/biweekly | 28 and 49 days | Teichman SL 2006 |
These are the conditions researchers used, not recommended cycles. Research Use Only. Not for human consumption, therapeutic, veterinary or any in-vivo use.
BPC-157
Mechanism
BPC-157 (Body Protection Compound-157) is a synthetic pentadecapeptide (15 amino acids) derived from a protein found in human gastric juice. It activates VEGFR2 for angiogenesis, stimulates nitric oxide via the Akt-eNOS axis, upregulates growth factors (EGF, FGF, HGF), recruits fibroblasts and tendon cells to injury sites, and modulates the NO-system and GABAergic system. Uniquely, it shows healing effects across virtually every tissue type studied. [1]
Doses used in published studies
| Model | Dose | Route | Duration | Ref |
|---|---|---|---|---|
| Rat, transected Achilles tendon | 10 µg/kg, 10 ng/kg or 10 pg/kg | Intraperitoneal, once daily | Up to 14 days | [1] |
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
- 10mg vial + 2 mL solvent = 5 mg/mL
References
- Staresinic M, et al. Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth. J Orthop Res. 2003. PMID 14554208
- Chang CH, et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. J Appl Physiol. 2011. PMID 21030672
TB-500 (Thymosin Beta-4)
Mechanism
TB-500 is a synthetic version of the 43-amino acid naturally occurring peptide Thymosin Beta-4 (Tβ4). Its primary mechanism is regulation of actin polymerization — the fundamental process that controls cell structure, migration, and tissue repair. It also upregulates VEGF (angiogenesis), reduces pro-inflammatory cytokines (IL-1β, TNF-α), and promotes stem cell migration and differentiation. [1]
Doses used in published studies
The cited studies don't report a dose in a usable form.
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
- 10mg vial + 2 mL solvent = 5 mg/mL
References
- Malinda KM, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999. PMID 10469335
- Goldstein AL, et al. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012. PMID 22074294
Semaglutide
Mechanism
Semaglutide is a 31-amino acid GLP-1 analog with 94% homology to native GLP-1(7-37). A C-18 fatty di-acid chain at Lys26 enables non-covalent albumin binding, extending plasma half-life to approximately 7 days — allowing once-weekly dosing. It resists DPP-4 degradation via an Aib substitution at position 8. Upon binding GLP-1R, it activates cAMP/PKA signaling in pancreatic beta cells, hypothalamic appetite centers, and cardiovascular tissue. [1]
Doses used in published studies
| Model | Dose | Route | Duration | Ref |
|---|---|---|---|---|
| Human, adults with overweight/obesity (STEP 1, n=1,961) | 2.4 mg | Subcutaneous, once weekly | 68 weeks | [1] |
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
- 10mg vial + 2 mL solvent = 5 mg/mL
- 15mg vial + 2 mL solvent = 7.5 mg/mL
References
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021. PMID 33567185
Tirzepatide
Mechanism
Tirzepatide is a 39-amino acid synthetic peptide and the first dual GIP/GLP-1 receptor agonist. It is built on the GIP sequence backbone with GLP-1 activity engineered in. A C20 fatty diacid moiety enables albumin binding for once-weekly dosing. GIP receptor activation enhances insulin sensitivity, improves lipid metabolism, and may have direct effects on adipose tissue remodeling. The dual agonism creates synergistic metabolic effects that exceed either pathway alone. [1]
Doses used in published studies
| Model | Dose | Route | Duration | Ref |
|---|---|---|---|---|
| Human, adults with obesity (SURMOUNT-1) | 5 mg, 10 mg or 15 mg | Subcutaneous, once weekly | 72 weeks | [1] |
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
- 10mg vial + 2 mL solvent = 5 mg/mL
- 15mg vial + 2 mL solvent = 7.5 mg/mL
References
- Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022. PMID 35658024
Retatrutide
Mechanism
Retatrutide (LY3437943) is a 39-amino acid first-in-class triple agonist simultaneously activating GLP-1, GIP, and glucagon receptors. A C20 fatty diacid moiety enables albumin binding for once-weekly dosing. The glucagon component is the key differentiator — it directly increases resting energy expenditure (thermogenesis) and drives hepatic fat oxidation, adding a 'burn more' mechanism on top of the 'eat less' incretin pathways. [1]
Doses used in published studies
| Model | Dose | Route | Duration | Ref |
|---|---|---|---|---|
| Human, adults with obesity (Phase 2) | 1, 4, 8 or 12 mg (escalated from 2 or 4 mg) | Subcutaneous, once weekly | 48 weeks | [1] |
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
References
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023. PMID 37366315
GHK-Cu (Copper Peptide)
Mechanism
GHK-Cu is a naturally occurring tripeptide (Gly-His-Lys) complexed with copper(II) ions. Found in human plasma, saliva, and urine, declining significantly with age (200 ng/mL at age 20 → 80 ng/mL by age 60). Genomic studies reveal it modulates approximately 4,000 human genes (~6% of the genome), systematically shifting gene expression patterns from 'aged' toward 'youthful' profiles. [1]
Doses used in published studies
The cited studies don't report a dose in a usable form.
Laboratory handling
- 50mg vial + 3 mL solvent = 16.67 mg/mL
References
- Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci. 2018. PMID 29986520
Ipamorelin
Mechanism
Ipamorelin is a synthetic pentapeptide that selectively activates the growth hormone secretagogue receptor (GHS-R1a). What makes it unique among GHRPs is its exceptional selectivity — it stimulates GH release without measurably affecting cortisol, prolactin, aldosterone, or hunger (ghrelin-like effects). It is considered the 'cleanest' GHRP available. [1]
Doses used in published studies
| Model | Dose | Route | Duration | Ref |
|---|---|---|---|---|
| Primary rat pituitary cells | EC50 1.3 nmol/L | In vitro | Acute | [1] |
| Conscious swine | ED50 2.3 nmol/kg | Intravenous | Single dose | [1] |
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
- 10mg vial + 2 mL solvent = 5 mg/mL
References
- Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. PMID 9849822
CJC-1295 w/DAC
Mechanism
CJC-1295 with DAC (Drug Affinity Complex) is a synthetic GHRH analog conjugated with a maleimidopropionic acid linker that spontaneously binds serum albumin after injection. This molecular anchor extends the half-life to 6-8 days — compared to native GHRH's 7-minute half-life. It mimics endogenous GHRH signaling at the pituitary, maintaining natural pulsatile GH release patterns while providing sustained baseline elevation. [1]
Doses used in published studies
| Model | Dose | Route | Duration | Ref |
|---|---|---|---|---|
| Human, healthy adults 21–61 yr | Ascending single doses; best tolerated at 30 or 60 µg/kg | Subcutaneous, single or weekly/biweekly | 28 and 49 days | [1] |
Laboratory handling
- 5mg vial + 2 mL solvent = 2.5 mg/mL
References
- Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006. PMID 16352683
Lab results: how reports are chosen and what they mean
Every product lists the laboratory documentation behind the vial — here is how to read it. See the purity testing guide and the COA verification guide for detail.
How are the lab reports for each product chosen?
Each vial is tied to a lot-specific report from an independent third-party laboratory — not the manufacturer's own in-house data. A usable report is selected on four criteria: it names the compound and the exact production lot, it is dated, it identifies the testing laboratory, and it covers both reverse-phase HPLC purity and LC-MS mass-spectrometry identity. The lot number on the report must match the lot number printed on the vial you receive, so the published results describe the material actually in your shipment. Where a lab document cannot be verified against those criteria, it is not published.
What do the lab results mean?
Purity (HPLC): the percentage of the sample that is the target peptide, measured after chromatographic separation. Research-grade material is typically ≥98%, with the remaining signal coming from synthesis-related impurities such as deletion sequences. Identity (LC-MS): the observed molecular mass compared with the theoretical mass of the sequence, confirming the compound is what its label says rather than a lookalike. Net peptide content, when reported, states how much of the total powder weight is actual peptide versus salts and water. Together, purity and identity tell you the sample is clean and is the correct compound.
Why must the lab report match my vial's lot number?
Peptides are produced in discrete batches, and each batch can differ slightly in purity. A COA for a different lot says nothing about the vial in front of you. Matching the lot number confirms the published purity and identity results apply to the exact material you received, which is why the lab documents on each product page are keyed to production lots.
General Handling for All Peptides
- Store lyophilized powder sealed at −20 °C, protected from light and moisture; allow the vial to reach room temperature before opening to limit condensation.
- Reconstitute with sterile or bacteriostatic water, adding solvent slowly down the vial wall and swirling gently — do not shake.
- Store reconstituted solution at 2–8 °C and use within about 28 days; avoid repeated freeze–thaw cycles by aliquoting if longer storage is needed.
- Record lot number and reconstitution date on every vial so results trace back to the matching Certificate of Analysis.
Browse the shop, compare prices on the pricing page, or read the buying guide.
Research Use Only. Not for human consumption, therapeutic, veterinary or any in-vivo use.
