Side-by-side · Research reference

MT-1vsSermorelin

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

AFDA-ApprovedHUMAN-REVIEWED9/51 cited

BPhase 3HUMAN-REVIEWED14/43 cited

MT-1

α-MSH Analogue · FDA-Approved

16 mgImplant dose

13 AAPeptide lengthChawathe 2026

2019FDA approval

SQ Implant · 60-Day Release

Sermorelin

GHRH 1-29 fragment · Short-acting

100–500 mcgPer doseMolteno 2013

Phase 3Evidence levelWalker 1994 Molteno 2013

~12 minHalf-lifeMolteno 2013

SQ · Pre-sleep · 1×/day

01Mechanism of Action

Parameter

MT-1

Sermorelin

Primary target

Melanocortin-1 receptor (MC1R) on melanocytesLangan 2010

Pituitary GHRH receptorWalker 1994

Pathway

α-MSH analogue → MC1R activation → cAMP elevation → MITF transcription → eumelanin synthesis

GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994

Downstream effect

Increased melanogenesis, photoprotection, reduced UV sensitivityLangan 2010

Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013

Feedback intact?

Yes — exogenous MC1R agonism does not suppress endogenous α-MSH production

Yes — short pulse preserves feedback

Origin

Synthetic 13-AA peptidomimetic with norleucine (position 4) and D-phenylalanine (position 7) substitutions for metabolic stabilityChawathe 2026

Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994

Antibody development

—

02Dosage Protocols

Parameter

MT-1

Sermorelin

Standard dose

16 mg subcutaneous implant

FDA-approved formulation (Scenesse).

100–500 mcg per injectionMolteno 2013

Frequency

Every 60 days

Sustained release implant — no daily administration required.

Once daily, pre-sleep

Evidence basis

Phase 3 RCT / FDA-approved orphan drug

Phase 3 (Geref pediatric); clinical practiceWalker 1994 Molteno 2013

Indication

Erythropoietic protoporphyria (EPP)

Narrow FDA approval — not licensed for cosmetic tanning.

—

Duration

Seasonal use (spring–autumn typical)

Aligned with peak UV exposure months.

8–12 weeks per cycle

Route

Subcutaneous implant — upper arm or abdomen

—

Stability

Norleucine/D-Phe substitutions enhance peptidase resistance

Modified structure vs endogenous α-MSH (Met⁴, L-Phe⁷).

—

Lower / starter dose

—

100 mcg per dose

Reconstitution

—

Bacteriostatic water

Timing

—

Pre-sleep, fasted preferred

Half-life

—

~12 min (plasma)Molteno 2013

Shorter than tesamorelin (~26 min) — simpler GHRH analogue.

04Side Effects & Safety

Parameter

MT-1

Sermorelin

Nausea

Common (>10%) — mild, transient

—

Implant site reaction

Erythema, bruising, tenderness at insertion site

—

Hyperpigmentation

Generalised tanning (therapeutic effect), darkening of freckles/neviLangan 2010 Habbema 2017

Expected melanogenic response — complicates pigmented lesion surveillance.

—

Melanocytic changes

Rapid pigmentation of existing nevi; new melanocytic lesions reported with unregulated useHabbema 2017

Requires dermatologic monitoring; theoretical melanoma concern with chronic stimulation.

—

Headache

Occasional (MC1R-independent melanocortin effects)

—

Photosensitivity (paradoxical)

Rare phototoxic reactions despite melanin increase

—

Contamination risk (unregulated)

Impurity, infection, blood-borne virus transmission from illicit melanotan productsLangan 2010 Habbema 2017

Applies to internet/gym-sourced 'melanotan' — not FDA-approved Scenesse.

—

Injection site reaction

—

Mild erythema, transient pain

Flushing / headache

—

Common transient effect

IGF-1 elevation

—

Modest at standard doses

Cancer risk

—

Contraindicated in active malignancy (GH/IGF-1 axis)

Pregnancy / OB

—

Avoid

Glucose handling

—

Generally neutral

Absolute Contraindications

MT-1

·Hypersensitivity to afamelanotide or excipients
·Hepatic impairment (no safety data)
·Renal impairment (no safety data)

Sermorelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Relative Contraindications

MT-1

·History of melanoma or atypical nevi (melanocortin receptor stimulation concern)Habbema 2017
·Pregnancy/lactation (insufficient data)
·Photosensitive dermatoses (other than EPP)

Sermorelin

·Untreated diabetes

05Administration Protocol

Parameter

MT-1

Sermorelin

1. Implant insertion

Performed by trained healthcare provider. Sterile technique. Small incision in upper arm (triceps) or lower abdomen using trocar. 16 mg rod (4 mm × 1.5 cm) inserted subcutaneously.

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

2. Site care

Pressure applied post-insertion. Sterile dressing × 24 hrs. Avoid strenuous activity for 24–48 hrs to prevent extrusion.

SQ — abdomen or thigh. Rotate sites.

3. Release kinetics

Slow biodegradable polymer matrix releases afamelanotide over 60 days, maintaining therapeutic plasma levels without daily dosing.

Pre-sleep, fasted.

4. Repeat dosing

New implant every 60 days during high UV season (spring–autumn in temperate climates). Rotate implant sites to avoid scarring.

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

5. Monitoring

Baseline and periodic dermatologic exams to document pigmented lesions. Patient education on self-examination for new/changing nevi.

29–31G, 4–8 mm insulin syringe.

06Stack Synergy

MT-1

— no documented stacks

Sermorelin

+ Ipamorelin

Strong

View Ipamorelin →

Sermorelin (GHRH analogue) and ipamorelin (selective GHRP) form the prototypical GHRH+GHRP dual-axis stack at the lowest cost. Both peak within 30 min and produce a sharp physiological GH pulse without cortisol/prolactin elevation.

Sermorelin: 200–300 mcg SQ · pre-sleep
Ipamorelin: 200–300 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation, recovery, body composition

Raun 1998 Walker 1994