Side-by-side · Research reference

Melanotan-IIvsThymalin

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

APhase 1Reviewed9/43 cited

BHuman-MechanisticDraft12/40 cited

Melanotan-II

MC1R + MC4R agonist · Tanning + sexual response

0.25–1.0 mgPer doseDorr 1996

Phase 1Evidence levelDorr 1996

~1 hrHalf-life

SQ · Abdomen · Loading 5–7 days, then maintenance

Thymalin

Immune restorer · Russian peptide bioregulator

5–10 mgPer cycle doseKhavinson 2002

HumanMechanisticKhavinson 2002

HoursHalf-life (est)

IM · Daily for 5–10 days · 1-2×/year

01Mechanism of Action

Parameter

Melanotan-II

Thymalin

Primary target

MC1R (skin) + MC3R + MC4R (CNS sexual / appetite)Dorr 1996

T-cell precursors + thymus-axis maturation pathwayKhavinson 2002

Pathway

MC1R agonism → melanocyte tyrosinase → eumelanin synthesis. MC4R → autonomic sexual arousal centresDorr 1996 Simerly 2023

Modulation of T-cell differentiation + thymic hormone restoration in age-involuted thymusKhavinson 2002

Downstream effect

Skin darkening, photo-protection, increased sexual desire / spontaneous erectionDorr 1996

Restored T-cell populations, improved immune surveillance, reduced infection rates in elderlyKhavinson 2002

Feedback intact?

—

Origin

Cyclic 7-AA modified α-MSH analog; designed at University of ArizonaDorr 1996

Polypeptide fraction isolated from calf thymus extractKhavinson 2002

Antibody development

—

02Dosage Protocols

Parameter

Melanotan-II

Thymalin

Loading phase

0.25–0.5 mg/day SQ × 5–7 daysDorr 1996

Builds up to visible tan.

—

Maintenance

0.5–1.0 mg 1–2×/week

After visible tan develops; supports with UV exposure.

—

Frequency

Daily during loading; 1–2× per week maintenance

Once daily during cycle

Lower / starter dose

0.1 mg / day

Conservative starter — assess tolerability for nausea.

2.5 mg / day

Evidence basis

Phase 1 + anecdotalDorr 1996

Russian clinical + in vitroKhavinson 2002

Duration

8–12 weeks per cycle

5–10 day cycles, 1–2× per year

Reconstitution

Bacteriostatic water; protect from light

Saline or bacteriostatic water

Timing

Evening preferred (24h tan-development cycle)

Morning preferred

Half-life

~1 hour plasma; effects on melanocytes persist days

Hours (estimated)

Standard dose

—

5–10 mg / day IM × 5–10 daysKhavinson 2002

04Side Effects & Safety

Parameter

Melanotan-II

Thymalin

Nausea

Common, especially loading phase

—

Flushing

Common transient

—

Spontaneous erection

Common in men — MC4R cross-effectDorr 1996

—

Increased mole / freckle pigmentation

Existing moles darken; new lesions possible

—

Melanoma risk

Theoretical concern — increased melanocyte activity; CAUTION in melanoma history

—

Appetite suppression

MC4R-mediated; mild

—

Pregnancy / OB

Contraindicated

Avoid

Injection site reaction

—

Mild erythema at IM site

Allergic reaction

—

Rare hypersensitivity to bovine-derived polypeptide

Autoimmune flare

—

Theoretical risk in active autoimmune disease

Long-term safety

—

Limited Western data

Absolute Contraindications

Melanotan-II

·History of melanoma or atypical mole syndrome
·Pregnancy / breastfeeding
·Active uncontrolled hypertension

Thymalin

·Pregnancy / breastfeeding
·Bovine protein hypersensitivity

Relative Contraindications

Melanotan-II

·Significant freckling / dysplastic nevus
·Personal or family melanoma history

Thymalin

·Active autoimmune disease
·Concurrent immunosuppressant therapy

05Administration Protocol

Parameter

Melanotan-II

Thymalin

1. Reconstitution

Add 2 mL bacteriostatic water to 10 mg vial → 5 mg/mL = 500 mcg per 0.1 mL. Light-protected.

Add 1–2 mL saline or bacteriostatic water per 10 mg vial.

2. Injection site

SQ — abdomen. Rotate sites.

Intramuscular — deltoid or gluteal. Rotate sites.

3. Timing

Evening preferred. UV exposure (sunlight or tanning bed) helps develop tan.

Morning preferred during cycle.

4. Storage

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

Lyophilised: refrigerate, light-protected. Reconstituted: use immediately.

5. Needle

29–31G insulin syringe.

23–25G, 25–38 mm IM needle.

06Stack Synergy

Melanotan-II

— no documented stacks

Thymalin

+ Thymosin α-1

Moderate

View Thymosin α-1 →

Thymalin is a polypeptide complex; Thymosin α-1 is a single purified peptide. Both target the thymus-axis but at different levels — Thymalin restores broad thymic signaling; Tα-1 provides a specific molecular activator. Anecdotally combined for elderly immune support.

Thymalin: 5–10 mg IM · daily × 7 days
Thymosin α-1: 1.6 mg SQ · 2× weekly during the cycle
Primary benefit: Broad thymic restoration + targeted immune activation

Khavinson 2002 Camerini 2001