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Specimen Atlas of Research Peptides81 plates · MIT
Side-by-side · Research reference

CortagenvsPT-141

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AAnimal-MechanisticHUMAN-REVIEWED11/35 cited
BFDA-ApprovedHUMAN-REVIEWED13/41 cited
Cortagen
Bioregulatory Tetrapeptide · Khavinson-School
TetrapeptideStructure
↓ LPO productsAntioxidant effectKozina 2007
AnimalEvidence level
Injectable · Animal models
PT-141
MC4R Agonist · FDA-Approved (HSDD)
SQ · Abdomen / thigh · ≥45 min before sex

01Mechanism of Action

Parameter
Cortagen
PT-141
Primary target
Cerebral cortex tissue — molecular targets under investigation
Melanocortin-4 receptor (MC4R) in hypothalamusSimerly 2023VYLEESI (bremelanotide injecti 2019
Pathway
Antioxidant pathway modulation — suppression of LPO cascade, reduction of protein oxidative modificationKozina 2007
MC4R agonism in paraventricular nucleus → autonomic + neuroendocrine sexual arousal pathwaysSimerly 2023
Downstream effect
Decreased lipid peroxidation products, reduced oxidative protein damage, altered gene expression in cardiac tissueKozina 2007Anisimov 2004
Increased sexual desire and arousal; central rather than peripheral mechanismClayton 2015
Feedback intact?
Origin
Synthetic tetrapeptide derived from amino acid analysis of natural brain cortex peptide preparation CortexinAnisimov 2004
Cyclic 7-AA peptide derived from α-MSH (agonist Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-OH cyclic)VYLEESI (bremelanotide injecti 2019
Antibody development

02Dosage Protocols

Parameter
Cortagen
PT-141
Animal model dose (rat)
Injection protocol (dose not specified in abstracts)
Multiple injections over study period.
Avian model dose (chicken)
40-day injection courseKuznik 2008
Compared to epithalon in hypophysectomized and aged birds.
Human peripheral nerve study
Therapeutic course (protocol details not provided)
Posttraumatic recovery context — reference cited but not detailed.
Evidence basis
Animal mechanistic studies
FDA-approved (HSDD pre-menopausal women)VYLEESI (bremelanotide injecti 2019Clayton 2015
Route
Injectable (inferred from animal protocols)
Standard dose
1.75 mg SQVYLEESI (bremelanotide injecti 2019
Single dose ≥45 min before anticipated sexual activity. Max 1 dose / 24 hr.
Frequency
PRN, max 8 doses / month
Lower / starter dose
1 mg (off-label)
Duration
PRN; reassess if no benefit after 8 doses
Reconstitution
Pre-filled commercial pen (Vyleesi). Research vial: bacteriostatic water.
Timing
≥45 min before sexual activity

04Side Effects & Safety

Parameter
Cortagen
PT-141
Antioxidant suppression
Suppression of antioxidant activity noted alongside LPO reductionKozina 2007
Mechanism unclear — possible homeostatic adaptation.
Immune/hemostasis effects
No effect on immunity or hemostasis parameters in avian hypophysectomy model (unlike epithalon)Kuznik 2008
Epithalon reversed deficits; cortagen did not.
Human safety data
No adverse events reported in peripheral nerve recovery context
Limited detail in available abstracts.
Nausea
Common (~40%); often transientVYLEESI (bremelanotide injecti 2019
Flushing
Common, transient
Injection site reaction
Erythema, mild pain
Headache
Common
Hyperpigmentation (focal)
Rare focal skin darkening; reversible after discontinuationVYLEESI (bremelanotide injecti 2019
Hypertension (transient)
Mean ↑6 mmHg systolic peaking ~4 h post-dose; resolves within 12 hVYLEESI (bremelanotide injecti 2019
Pregnancy / OB
Contraindicated
Cardiovascular disease
Use caution; transient BP rise
Absolute Contraindications
Cortagen
PT-141
  • ·Uncontrolled hypertension
  • ·Known cardiovascular disease (caution)
  • ·Pregnancy
Relative Contraindications
Cortagen
PT-141
  • ·Pre-existing hyperpigmentation disorders
  • ·MC4R-pathway-dependent psychiatric conditions

05Administration Protocol

Parameter
Cortagen
PT-141
1. Preparation
Reconstitute lyophilised peptide with bacteriostatic water per supplier protocol. Exact volumes depend on concentration supplied.
Vyleesi: pre-filled auto-injector. Research vial: 2 mL bacteriostatic water per 10 mg → 5 mg/mL.
2. Injection site
Subcutaneous injection typical for bioregulatory peptides — abdomen or thigh. Rotate sites.
SQ — abdomen or thigh.
3. Timing
Animal protocols used repeated dosing over weeks. Human timing not established — evening administration common in Khavinson tradition.
≥45 min before sexual activity for peak effect. Effect persists ~6–8 h.
4. Storage
Lyophilised: refrigerate or freeze per supplier. Reconstituted: refrigerate 2–8 °C, use within guideline window.
Vyleesi: room temp ≤30 °C. Research vial: refrigerate after reconstitution.
5. Needle
Auto-injector (Vyleesi) or 29–31G, 4–8 mm insulin syringe.