Side-by-side · Research reference
MT-1vsSS-31
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-REVIEWED9/43 cited
MT-1
α-MSH Analogue · FDA-Approved
SQ Implant · 60-Day Release
SS-31
Cardiolipin-binding · Mitochondrial protective
SQ · Abdomen · Once daily
01Mechanism of Action
Parameter
MT-1
SS-31
Primary target
Melanocortin-1 receptor (MC1R) on melanocytesLangan 2010
Cardiolipin in inner mitochondrial membraneSzeto 2014
Pathway
α-MSH analogue → MC1R activation → cAMP elevation → MITF transcription → eumelanin synthesis
Cardiolipin binding → cristae stabilisation → ETC integrity → reduced ROS + preserved ATP synthesisSzeto 2014Szilagyi 2009
Downstream effect
Increased melanogenesis, photoprotection, reduced UV sensitivityLangan 2010
Mitochondrial bioenergetic preservation; cardio-, neuro-, and reno-protective effects in animal + clinical studiesSzeto 2014
Feedback intact?
Yes — exogenous MC1R agonism does not suppress endogenous α-MSH production
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Origin
Synthetic 13-AA peptidomimetic with norleucine (position 4) and D-phenylalanine (position 7) substitutions for metabolic stabilityChawathe 2026
Synthetic tetrapeptide D-Arg-Dmt-Lys-Phe-NH₂; cell-permeable, mitochondrial-selectiveSzeto 2014
Antibody development
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02Dosage Protocols
Parameter
MT-1
SS-31
Standard dose
16 mg subcutaneous implant
FDA-approved formulation (Scenesse).
40 mg / day SQ (clinical trials)Szeto 2014
Anecdotal community range 5-10 mg/day. Phase 3 trials use 40 mg.
Frequency
Every 60 days
Sustained release implant — no daily administration required.
Once daily
Evidence basis
Phase 3 RCT / FDA-approved orphan drug
Multiple Phase 3 trials (Barth, AMD, ischemia-reperfusion)Szeto 2014Szilagyi 2009
Indication
Erythropoietic protoporphyria (EPP)
Narrow FDA approval — not licensed for cosmetic tanning.
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Duration
Seasonal use (spring–autumn typical)
Aligned with peak UV exposure months.
Indefinite for mitochondrial disease; cycled for healthspan use
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
—
5 mg / day (anecdotal)
Reconstitution
—
Bacteriostatic water
Timing
—
Morning fasted preferred; pre-workout for exercise-induced mitochondrial stress
Half-life
—
~3 h plasma; tissue uptake longer
04Side Effects & Safety
Parameter
MT-1
SS-31
Nausea
Common (>10%) — mild, transient
—
Implant site reaction
Erythema, bruising, tenderness at insertion site
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Hyperpigmentation
Generalised tanning (therapeutic effect), darkening of freckles/neviLangan 2010Habbema 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)
Reported in some Phase 3 trials
Photosensitivity (paradoxical)
Rare phototoxic reactions despite melanin increase
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Contamination risk (unregulated)
Impurity, infection, blood-borne virus transmission from illicit melanotan productsLangan 2010Habbema 2017
Applies to internet/gym-sourced 'melanotan' — not FDA-approved Scenesse.
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Injection site reaction
—
Erythema, mild pruritus
GI symptoms
—
Nausea (uncommon)
Cardiovascular
—
Cardio-protective in studies; no signal of harm
Pregnancy / OB
—
Avoid — insufficient data
Absolute Contraindications
MT-1
- ·Hypersensitivity to afamelanotide or excipients
- ·Hepatic impairment (no safety data)
- ·Renal impairment (no safety data)
SS-31
- ·Pregnancy / breastfeeding
- ·Hypersensitivity to peptide
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)
SS-31
- ·None established
05Administration Protocol
Parameter
MT-1
SS-31
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 bacteriostatic water per label. Light-protected handling.
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.
Morning fasted; pre-workout for exercise-augmented mitochondrial stress.
4. Repeat dosing
New implant every 60 days during high UV season (spring–autumn in temperate climates). Rotate implant sites to avoid scarring.
Lyophilised: refrigerate, 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
SS-31
+ MOTS-c
ModerateSS-31 and MOTS-c address mitochondrial decline through complementary axes. SS-31 protects existing mitochondrial structure (cardiolipin binding, cristae stabilisation). MOTS-c upregulates AMPK/PGC-1α, triggering biogenesis of new mitochondria. Together they pair preservation with renewal — anecdotally favoured in healthspan and post-cardio-event recovery protocols.
- SS-31
- 5–10 mg SQ · daily morning
- MOTS-c
- 5 mg SQ · 2× per week pre-workout
- Primary benefit
- Mitochondrial preservation + biogenesis