Side-by-side · Research reference

DihexavsMT-1

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

AAnimal-StrongHUMAN-REVIEWED7/28 cited

BFDA-ApprovedHUMAN-REVIEWED9/51 cited

Dihexa

Angiotensin IV Analogue · Pre-Clinical

Pre-clinicalDevelopment stage

Rodent onlyEvidence basisBenoist 2014

HGF/c-MetTarget systemWright 2015

Not established — animal studies only

MT-1

α-MSH Analogue · FDA-Approved

16 mgImplant dose

13 AAPeptide lengthChawathe 2026

2019FDA approval

SQ Implant · 60-Day Release

01Mechanism of Action

Parameter

Dihexa

MT-1

Primary target

c-Met receptor (HGF receptor tyrosine kinase)

Melanocortin-1 receptor (MC1R) on melanocytesLangan 2010

Pathway

HGF/c-Met receptor activation → downstream signaling cascade → synaptogenesis and dendritic arborization

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

Downstream effect

Induction of dendritic arborization, synapse formation, neurogenesis, and neuroprotection in rodent models

Increased melanogenesis, photoprotection, reduced UV sensitivityLangan 2010

Feedback intact?

—

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

Origin

Small-molecule angiotensin IV analogue designed to activate HGF/c-Met systemWright 2015

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

Antibody development

—

02Dosage Protocols

Parameter

Dihexa

MT-1

Human dosing

Not established — no human trials

—

Animal studies

Mouse/rat models only — dosing not translatable to humans

—

Evidence basis

Pre-clinical / Rodent models

Phase 3 RCT / FDA-approved orphan drug

Clinical status

No Phase 1, 2, or 3 trials published

—

Standard dose

—

16 mg subcutaneous implant

FDA-approved formulation (Scenesse).

Frequency

—

Every 60 days

Sustained release implant — no daily administration required.

Indication

—

Erythropoietic protoporphyria (EPP)

Narrow FDA approval — not licensed for cosmetic tanning.

Duration

—

Seasonal use (spring–autumn typical)

Aligned with peak UV exposure months.

Route

—

Subcutaneous implant — upper arm or abdomen

Stability

—

Norleucine/D-Phe substitutions enhance peptidase resistance

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

04Side Effects & Safety

Parameter

Dihexa

MT-1

Human safety data

None available — no human clinical trials

—

Theoretical c-Met risks

c-Met receptor activation has been implicated in tumorigenesis; unknown cancer risk profile

—

Pre-clinical tolerability

Not systematically reported in available studies

—

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.

Absolute Contraindications

Dihexa

·Not approved for human use — research compound only

MT-1

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

Relative Contraindications

Dihexa

·Theoretical contraindication: active or history of malignancy (c-Met pathway involvement in cancer)

MT-1

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

05Administration Protocol

Parameter

Dihexa

MT-1

1. Human administration

No established protocol. Dihexa has not been tested in human subjects. Animal studies used various routes (typically subcutaneous or intraperitoneal in rodents) not translatable to clinical use.

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.

2. Legal status

Pre-clinical research compound. Not approved by FDA or any regulatory authority for human use.

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

3. Release kinetics

—

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

4. Repeat dosing

—

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

5. Monitoring

—

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