Side-by-side · Research reference

PT-141vsSelank

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

AFDA-ApprovedReviewed13/41 cited

BHuman-MechanisticDraft11/40 cited

PT-141

MC4R Agonist · FDA-Approved (HSDD)

1.75 mgPer doseVYLEESI (bremelanotide injecti 2019

Pre-sexTimingVYLEESI (bremelanotide injecti 2019

~2.7 hrHalf-lifeVYLEESI (bremelanotide injecti 2019

SQ · Abdomen / thigh · ≥45 min before sex

Selank

Anxiolytic + Cognitive · Russian Pharma

150–300 mcg/doseIntranasalZaderej 2014

HumanMechanisticZaderej 2014 Medvedev 2007

~30 minOnset

Intranasal · 2–3×/day during stress / cognitive demand

01Mechanism of Action

Parameter

PT-141

Selank

Primary target

Melanocortin-4 receptor (MC4R) in hypothalamusSimerly 2023 VYLEESI (bremelanotide injecti 2019

Monoamine system (serotonin / GABA modulation) + immunomodulation via tuftsin domainZaderej 2014

Pathway

MC4R agonism in paraventricular nucleus → autonomic + neuroendocrine sexual arousal pathwaysSimerly 2023

Tuftsin-derived immune signaling + CNS monoamine modulation → reduced anxiety + improved mood / cognitionMedvedev 2007

Downstream effect

Increased sexual desire and arousal; central rather than peripheral mechanismClayton 2015

Anxiolytic + cognitive enhancement; immunomodulation via increased IL-6 + IFN-γMedvedev 2007 Zaderej 2014

Feedback intact?

—

No GABA-receptor binding; no dependence reportedMedvedev 2007

Origin

Cyclic 7-AA peptide derived from α-MSH (agonist Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-OH cyclic)VYLEESI (bremelanotide injecti 2019

Synthetic 7-AA peptide derived from human tuftsin (immune-system tetrapeptide)Zaderej 2014

Antibody development

—

02Dosage Protocols

Parameter

PT-141

Selank

Standard dose

1.75 mg SQVYLEESI (bremelanotide injecti 2019

Single dose ≥45 min before anticipated sexual activity. Max 1 dose / 24 hr.

150–300 mcg / dose intranasalZaderej 2014

Frequency

PRN, max 8 doses / month

2–3× per day during stress

Lower / starter dose

1 mg (off-label)

75 mcg / dose

Evidence basis

FDA-approved (HSDD pre-menopausal women)VYLEESI (bremelanotide injecti 2019 Clayton 2015

Human-mechanistic + Russian clinical trialsMedvedev 2007

Duration

PRN; reassess if no benefit after 8 doses

10–14 day cycles, repeated as needed

Reconstitution

Pre-filled commercial pen (Vyleesi). Research vial: bacteriostatic water.

Pre-formulated nasal spray (commercial); research vial: bacteriostatic water

Timing

≥45 min before sexual activity

Morning + early afternoon preferred

Half-life

~2.7 hrVYLEESI (bremelanotide injecti 2019

Short (minutes plasma); CNS effect lasts ~3 hr

04Side Effects & Safety

Parameter

PT-141

Selank

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

Avoid — insufficient data

Cardiovascular disease

Use caution; transient BP rise

—

Nasal irritation

—

Mild burning or congestion (transient)

Sedation

—

None — distinct from benzodiazepinesMedvedev 2007

Dependence / withdrawal

—

None reported in clinical useZaderej 2014

Cognitive impairment

—

None — opposite effect (enhancement)

Allergic reaction

—

Rare hypersensitivity

Long-term safety

—

Limited Western RCT data

Absolute Contraindications

PT-141

·Uncontrolled hypertension
·Known cardiovascular disease (caution)
·Pregnancy

Selank

·Pregnancy / breastfeeding
·Hypersensitivity to peptide

Relative Contraindications

PT-141

·Pre-existing hyperpigmentation disorders
·MC4R-pathway-dependent psychiatric conditions

Selank

·Active autoimmune disease (theoretical via immunomodulation)

05Administration Protocol

Parameter

PT-141

Selank

1. Reconstitution

Vyleesi: pre-filled auto-injector. Research vial: 2 mL bacteriostatic water per 10 mg → 5 mg/mL.

Pre-formulated nasal spray (commercial) or research vial reconstituted with bacteriostatic water.

2. Injection site

SQ — abdomen or thigh.

Intranasal — 1–3 sprays per nostril per dose. Tilt head slightly back.

3. Timing

≥45 min before sexual activity for peak effect. Effect persists ~6–8 h.

Morning + early afternoon for cognitive demand; PRN for acute anxiety.

4. Storage

Vyleesi: room temp ≤30 °C. Research vial: refrigerate after reconstitution.

Refrigerate after reconstitution; ≤30 days. Light-protected.

5. Needle

Auto-injector (Vyleesi) or 29–31G, 4–8 mm insulin syringe.

Avoid co-administration with strong sedatives or other anxiolytics initially.