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Peptide Database

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Fat LossMuscle BuildingInjury HealingAnti-AgingCognitive EnhancementSleep OptimizationImmune SupportGut HealingSkin RejuvenationSexual Health
Peptides
Abarelix
Hormone Support
Acetyl Hexapeptide-3 (Argireline)
Cosmetic
Adipotide
Weight Management
Adrenomedullin
Healing & Recovery
Alexamorelin
Growth Hormone
Angiotensin (1-7)
Healing & Recovery
AOD-9604
Weight Management
Apelin-13
Healing & Recovery
ARA-290 (Cibinetide)
Healing & Recovery
Bestatin (Ubenimex)
Immune
BPC-157
Healing & Recovery
Buserelin
Hormone Support
Cagrilintide
Weight Management
Capromorelin
Growth Hormone
Cartalax
Anti-Aging
Cathelicidin (hCAP-18 / Synthetic Derivatives)
Immune
Cerebrolysin
Cognitive
Cerluten
Cognitive
Cetrorelix
Hormone Support
Chonluten
Immune
CJC-1295 (No DAC)
Growth Hormone
CJC-1295 with DAC
Growth Hormone
Copper Tripeptide-1 (GHK-Cu)
Cosmetic
Cortexin
Cognitive
Crystagen
Immune
Daptomycin
Immune
Defensin (HBD-2)
Immune
Defensin (HBD-3)
Immune
Degarelix
Hormone Support
Dihexa
Cognitive
DSIP (Delta Sleep-Inducing Peptide)
Sleep & Recovery
Dulaglutide
Weight Management
Enalapril
Healing & Recovery
Epithalon
Anti-Aging
Exenatide
Weight Management
Fertirelin
Hormone Support
FOXO4-DRI
Anti-Aging
Ganirelix
Hormone Support
GHK-Cu
Cosmetic
GHRH (1-29)
Growth Hormone
GHRP-2
Growth Hormone
GHRP-6 (Growth Hormone Releasing Peptide-6)
Growth Hormone
Glutathione
Anti-Aging
Gonadorelin (GnRH)
Hormone Support
Gramicidin
Immune
Hexarelin
Growth Hormone
Human Chorionic Gonadotropin (HCG)
Hormone Support
Human Growth Hormone (HGH)
Growth Hormone
IGF-1 LR3
Growth Hormone
Immunoxel (Dzherelo)
Immune
Imunofan
Immune
Intermedin (Adrenomedullin-2)
Healing & Recovery
Ipamorelin
Growth Hormone
Kisspeptin-10
Sexual Health
KPV (Alpha-MSH Fragment)
Healing & Recovery
Lactoferricin B
Immune
Larazotide
Healing & Recovery
Lentinan
Immune
Leuphasyl
Cosmetic
Leuphasyl
Cosmetic
Leuprolide
Hormone Support
Liraglutide
Weight Management
Livagen
Anti-Aging
Lixisenatide
Weight Management
LL-37
Immune
Macimorelin
Growth Hormone
Magainin-2
Immune
Mazdutide
Weight Management
Melanotan-2
Cosmetic
MK-677 (Ibutamoren)
Growth Hormone
MOTS-c
Metabolic
Myristoyl Pentapeptide-17
Cosmetic
N-Acetyl Selank
Cognitive
N-Acetyl Semax Amidate
Cognitive
NAD+
Mitochondrial
Nafarelin
Hormone Support
Natriuretic Peptide (ANP)
Healing & Recovery
Nesiritide (BNP)
Healing & Recovery
Nisin
Immune
Noopept (Omberacetam)
Cognitive
Orforglipron
Weight Management
Ovagen
Anti-Aging
Oxytocin Acetate
Hormone Support
P21 (P021)
Cognitive
PACAP-38
Healing & Recovery
Palmitoyl Oligopeptide
Cosmetic
Palmitoyl Pentapeptide-4 (Matrixyl)
Cosmetic
Palmitoyl Tetrapeptide-7
Cosmetic
Palmitoyl Tripeptide-1
Cosmetic
Pancragen
Metabolic
PEG-MGF
Healing & Recovery
Pemvidutide
Weight Management
Pentadecapeptide (BPC Analog)
Healing & Recovery
Pidotimod
Immune
Pinealon
Cognitive
PNC-27
Immune
Polymyxin B
Immune
Pralmorelin (GHRP-2)
Growth Hormone
Pramlintide
Weight Management
Prostamax
Hormone Support
PT-141 (Bremelanotide)
Sexual Health
Relaxin-2 (Serelaxin)
Healing & Recovery
Retatrutide
Weight Management
Selank
Cognitive
Semaglutide
Weight Management
Semax
Cognitive
Sermorelin
Growth Hormone
Setmelanotide
Weight Management
SLU-PP-332
Metabolic
SM-130686
Growth Hormone
Snap-8
Cosmetic
SS-31 (Elamipretide)
Mitochondrial
Substance P Antagonists
Healing & Recovery
Survodutide
Weight Management
SYN-AKE
Cosmetic
Tabimorelin
Growth Hormone
TB-500
Healing & Recovery
Tesamorelin
Growth Hormone
Testagen
Hormone Support
Thymalin
Immune
Thymopentin (TP-5)
Immune
Thymopoietin
Immune
Thymosin Alpha-1
Immune
Thymosin Beta-4
Healing & Recovery
Thymulin (FTS)
Immune
Thymulin Analog (PAT)
Healing & Recovery
Tirzepatide
Weight Management
Tripeptide-29
Cosmetic
Triptorelin
Hormone Support
Ularitide
Healing & Recovery
Urocortin
Healing & Recovery
Ventfort
Anti-Aging
Vesilute
Hormone Support
Vilon
Immune
VIP (Vasoactive Intestinal Peptide)
Healing & Recovery
Xenin-25
Metabolic
Ziconotide (Prialt)
Healing & Recovery
Total Peptides: 137
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Peptide Comparison

PACAP-38vsThymosin Beta-4

Neuroprotective polypeptide with potent anti-inflammatory and cytoprotective properties discovered in 1989

The body's natural healing peptide that accelerates tissue repair and reduces inflammation

Healing & RecoveryHealing & Recovery

At a Glance

Quick
comparison

Dose Range

PACAP-38

5 pmol/kg/min–20 pmol/kg/min mg

Thymosin Beta-4

2–5 mg

Frequency

PACAP-38

Once daily

Thymosin Beta-4

Twice weekly

Administration

PACAP-38

Intravenous infusion

Thymosin Beta-4

Subcutaneous injection

Cycle Length

PACAP-38

Ongoing/indefinite

Thymosin Beta-4

8-12 weeks

Onset Speed

PACAP-38

Moderate (1-2 weeks)

Thymosin Beta-4

Moderate (1-2 weeks)

Evidence Level

PACAP-38

Strong human trials (Phase 3 or FDA approved)

Thymosin Beta-4

Moderate human trials (Phase 1-2)

Efficacy

Benefit
ratings

PACAP-38
Thymosin Beta-4

Neuroprotection

PACAP-3892%
Thymosin Beta-40%

Anti-Inflammatory

PACAP-3885%
Thymosin Beta-40%

Migraine Research

PACAP-3888%
Thymosin Beta-40%

Wound Healing

PACAP-380%
Thymosin Beta-495%

Inflammation Reduction

PACAP-380%
Thymosin Beta-488%

Tissue Regeneration

PACAP-380%
Thymosin Beta-492%

Technical Data

Compound
specifications

PACAP-38

Molecular Formula

C203H331N63O53S

Molecular Weight

~4534 Da

Half-Life

Very short plasma half-life (minutes); rapid enzymatic degradation

Bioavailability

IV: systemic; Intranasal: direct CNS access bypassing BBB; poor oral bioavailability

CAS Number

137061-48-4

Thymosin Beta-4

Molecular Formula

C212H350N56O78S

Molecular Weight

4963

Half-Life

Dose-dependent (increases with higher doses)

Bioavailability

100% (subcutaneous and intravenous)

CAS Number

77591-33-4

Protocols

Dosing
tiers

PACAP-38

standard

10 pmol/kg/min

Continuous infusion

20-minute single infusion

Standardized human experimental-medicine provocation dose; 10 pmol/kg/min over 20 min was selected as the optimal/maximum tolerated rate after dose-finding (5-20 pmol/kg/min) and is reproduced across headache-model trials [6][7][8]. Used as a research provocation agent, not an approved therapeutic.

Thymosin Beta-4

standard

2-5 mg (community injectable practice for 'TB-500')

Once or twice weekly

4-6 week loading phase, then weekly maintenance

Documented community/research-practice injectable dosing for tissue repair; thymosin beta-4 has ~100% bioavailability by the subcutaneous route [1]. Not an FDA-approved use.

standard

0.1% (1 mg/mL) RGN-259 solution, 1 drop

Several times daily (e.g. up to 5x/day)

4 weeks

0.1% RGN-259 ophthalmic solution used in phase III neurotrophic keratopathy and dry-eye trials, applied as eye drops several times daily for ~4 weeks [5].

advanced

450-1200 mg

IV push daily for the first 3 days, then weekly

Total of 7 doses over ~5 weeks

Doses studied in the RGN-352 acute myocardial infarction clinical program, given IV after PCI [6].

Applications

Best
suited for

PACAP-38

Neuroprotection research

PACAP-38 is particularly well-suited for individuals focused on neuroprotection research. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Stroke and traumatic brain injury investigation

PACAP-38 is particularly well-suited for individuals focused on stroke and traumatic brain injury investigation. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Migraine pathophysiology studies

PACAP-38 is particularly well-suited for individuals focused on migraine pathophysiology studies. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Anti-inflammatory mechanism research

PACAP-38 is particularly well-suited for individuals focused on anti-inflammatory mechanism research. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.

Thymosin Beta-4

Post-Surgery Recovery

Accelerates healing of surgical wounds and reduces post-operative inflammation and scarring

Chronic Wound Management

Helps pressure ulcers, venous stasis ulcers, and other slow-healing wounds progress faster

Tissue Regeneration

Supports repair of damaged tissues from injury, burns, or degenerative conditions

Safety Profile

Side
effects

PACAP-38

Common

  • Flushing
  • Tachycardia
  • Gastrointestinal Effects
  • Transient Warmth Sensation

Uncommon

  • Headache and Migraine Triggering
  • Hypotension

Serious

  • Systemic Hypotension and Cardiovascular Effects
  • Systemic Inflammatory Activation

Thymosin Beta-4

Common

  • Injection site redness
  • Injection site swelling

Uncommon

  • Temporary mild headache
  • Mild bruising at injection site
  • Transient fatigue

Serious

  • Allergic reaction

Research Status

Safety
& evidence

PACAP-38

Evidence Level

Strong human trials (Phase 3 or FDA approved)

FDA Status

Research compound

Safety Overview

PACAP-38 shows good tolerability in Phase II trials for migraine and pain conditions with minimal serious adverse events at IV doses of 2-6 mcg/kg. Primary side effects are transient flushing and headache (10-15% of subjects), likely related to vasodilation. Cardiovascular effects include mild heart rate increase and blood pressure changes, monitored in clinical settings. No carcinogenicity or teratogenicity in animal models; limited long-term safety data in humans.

Contraindications

  • xActive migraine or headache disorder (PACAP-38 is a potent migraine trigger)
  • xUncontrolled hypotension or cardiovascular instability
  • xNot approved for clinical use outside research settings
  • xInsufficient data for pregnancy and lactation safety

Thymosin Beta-4

Evidence Level

Moderate human trials (Phase 1-2)

FDA Status

Research compound

Safety Overview

Thymosin Beta-4 is a naturally occurring peptide found in all cells and body fluids in the human body. Clinical trials have demonstrated excellent safety even at very high doses. IV studies showed doses up to 1260 mg were well tolerated with no serious adverse events.

Contraindications

  • xActive systemic infections
  • xSevere immunosuppression
  • xHypersensitivity to thymosin or any component
  • xPregnancy (insufficient safety data)

Decision Guide

Which is
right for you?

Choose PACAP-38 if...

  • Neuroprotection research
  • Stroke and traumatic brain injury investigation
  • Migraine pathophysiology studies
  • Anti-inflammatory mechanism research

Choose Thymosin Beta-4 if...

  • Recovering from injuries or surgery
  • Improving wound healing speed
  • Reducing inflammation
  • Minimizing scar formation
PACAP-38 vs Thymosin Beta-4 — Peptide Comparison | Peptide Initiative