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Peptide Comparison

Alpha-MSH vs Relaxin

Both are Reproductive & Hormonal peptides.

Alpha-MSH

Alpha-Melanocyte Stimulating Hormone

RecoveryNot EvaluatedResearch Only

Half-life: ~3-5 minutes (plasma)

No providers listed yet

Full Alpha-MSH profile →
vs

Relaxin

Relaxin-2

Sexual HealthInvestigationalResearch Only

Half-life: ~7–8 h (terminal, serelaxin/rh-relaxin-2)

No providers listed yet

Full Relaxin profile →
Bottom line

Relaxin carries stronger published evidence (RCT, 5 key studies) than Alpha-MSH (Review, 12); both are research compounds.

Quick Verdict

Alpha-MSH

Half-life

~3-5 minutes (plasma)

Relaxin

Half-life

~7–8 h (terminal, serelaxin/rh-relaxin-2)

Which One Should You Choose?
Your goalBetter option
Stronger clinical evidenceRelaxin
Further along in FDA reviewRelaxin

Research summary only — not medical advice. Consult a qualified provider before making any decisions.

Side-by-Side Comparison
Alpha-MSH
Relaxin
Mechanism Family
Reproductive & Hormonal
Reproductive & Hormonal
Half-life
~3-5 minutes (plasma)
~7–8 h (terminal, serelaxin/rh-relaxin-2)
FDA Status
not evaluated
investigational
Admin Routes
subcutaneous, intranasal
subcutaneous, intravenous
Availability
Research Only
Research Only
Providers
None listed
None listed
Avail. Notes
Endogenous 13-aa neuropeptide. No FDA-approved drug. Bremelanotide (PT-141/Vyleesi) is an approved derivative but a distinct compound. Not on FDA 503A bulks list. Research use only.
—
Research Evidence

Alpha-MSH

Review · 12 key studies · most recent 2026

Relaxin

RCT · 5 key studies · most recent 2026
Research Citations

About Alpha-MSH

Melanocortin peptide; activates MC1R (pigmentation/anti-inflammatory), MC3R (energy balance), MC4R (appetite); suppresses NF-κB and pro-inflammatory cytokines

Research Areas
anti-inflammatoryappetite suppressionthermoregulationskin pigmentation

About Relaxin

Binds RXFP1 receptor, activating adenylyl cyclase and cAMP/PKA pathway. Upregulates matrix metalloproteinases (MMPs) to degrade excess collagen. Inhibits TGF-β fibrotic signaling. Promotes cervical softening and pelvic ligament compliance.

Research Areas
connective tissue remodelinganti-fibroticpelvic floor supportfertility supportcardiac protection
Safety Profile

Information below reflects published research data only — not medical advice. Consult a qualified provider before use.

Alpha-MSH

Reported (Unverified — Pending Clinical Review)
melanoma historyuncontrolled hypertension

No established clinical contraindications

Relaxin

No established clinical contraindications. This is an investigational compound with limited human data and has not been evaluated by the FDA for safety in this context. Consult a qualified clinician.

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Where to source these peptides

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Educational research tools — not medical advice.

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