Peptide Comparison
Melanotan-2vsGHK-Cu
A powerful synthetic peptide that mimics your body's natural tanning hormone, giving you a deeper, longer-lasting tan with minimal sun exposure while also showing surprising benefits for libido and appetite.
A naturally occurring copper peptide that acts like a master switch for your body's repair systems—boosting collagen production, accelerating wound healing, and helping your skin rebuild itself from the inside out.
At a Glance
Quick
comparison
Dose Range
Melanotan-2
100–500 mcg
GHK-Cu
1–3 mg
Frequency
Melanotan-2
Once daily
GHK-Cu
Once daily
Administration
Melanotan-2
Subcutaneous injection
GHK-Cu
Subcutaneous injection
Cycle Length
Melanotan-2
4-6 weeks
GHK-Cu
8-12 weeks
Onset Speed
Melanotan-2
Moderate (1-2 weeks)
GHK-Cu
Moderate (1-2 weeks)
Evidence Level
Melanotan-2
Limited human trials
GHK-Cu
Strong preclinical (extensive animal studies)
Efficacy
Benefit
ratings
Tanning Efficacy
Sexual Function
Tan Longevity
Skin Rejuvenation
Wound Healing
Tissue Regeneration
Technical Data
Compound
specifications
Melanotan-2
Molecular Formula
C50H69N15O9
Molecular Weight
1024.18 g/mol
Half-Life
33-36 hours
Bioavailability
High (subcutaneous injection)
CAS Number
121062-08-6
GHK-Cu
Molecular Formula
C14H23N6O4Cu
Molecular Weight
403.93 g/mol
Half-Life
Approximately 1 hour (plasma)
Bioavailability
High when injected subcutaneously; variable topically depending on formulation
CAS Number
49557-75-7
Protocols
Dosing
tiers
Melanotan-2
GHK-Cu
Applications
Best
suited for
Melanotan-2
Fair-Skinned Individuals Who Struggle to Tan
If you're the type who burns before you bronze, MT-2 can be a game-changer. It works by telling your skin cells to produce more melanin—the pigment that creates a tan. People who normally can't tan often see the most dramatic results.
Those Wanting to Reduce Sun Exposure
MT-2 means you need far less UV exposure to develop and maintain a tan. A few minutes of sun or a brief tanning bed session goes much further. This could potentially reduce your cumulative UV damage over time.
Year-Round Tan Maintenance
Unlike a natural tan that fades quickly, MT-2 tans last longer and can be maintained year-round with minimal upkeep. Many users find they can keep their summer color through winter with just weekly maintenance doses.
Those Experiencing Low Libido
MT-2 has significant effects on sexual arousal and function in both men and women. While PT-141 is more targeted for this purpose, some users appreciate getting tanning and libido benefits from one peptide.
GHK-Cu
Anti-Aging Warriors
If fine lines, sagging skin, and lost elasticity are your enemies, GHK-Cu is your secret weapon. It ramps up collagen and elastin production—the two proteins responsible for keeping your skin firm and youthful. Studies show it can tighten loose skin and improve elasticity better than many popular skincare ingredients.
Wound Healing Champions
Whether you're recovering from surgery, dealing with stubborn wounds, or healing from a cosmetic procedure, GHK-Cu accelerates the entire repair process. It attracts immune cells, builds new blood vessels, and stimulates the growth factors your body needs to rebuild tissue faster and better.
Scar Reducers
GHK-Cu doesn't just heal wounds—it helps remodel scar tissue. By regulating how your body lays down collagen during healing, it can help scars become flatter, softer, and more like surrounding normal skin. It even reduces the TGF-beta signals that lead to thick, raised scars.
Hair Growth Seekers
Research shows GHK-Cu can enlarge hair follicles and activate the Wnt/beta-catenin pathway—the signaling system that tells hair follicles to grow. If you're noticing thinning hair or increased shedding, this peptide may help stimulate thicker, healthier growth over time.
Safety Profile
Side
effects
Melanotan-2
Common
- Facial flushing
- Nausea
- Darkening of moles and freckles
- Spontaneous erections (men)
- Drowsiness and fatigue
Uncommon
- New mole formation
- Headaches
Serious
- Priapism (prolonged erection)
- Concerning mole changes
GHK-Cu
Common
- Injection site redness
- Skin tingling (topical use)
- Minor bruising
- Mild swelling at injection site
Uncommon
- Mild headache
- Temporary skin purging (topical)
Serious
- Allergic reaction
Research Status
Safety
& evidence
Melanotan-2
Evidence Level
Limited human trials
FDA Status
Not FDA approved
Safety Overview
Melanotan-2 has been studied in clinical trials and shows a generally acceptable short-term safety profile when used as directed. The most common side effects—nausea and flushing—are usually temporary and decrease with continued use. However, MT-2 is not FDA approved, and long-term safety data is limited. The main safety concern is the unknown effect on melanocytes (pigment-producing cells), particularly in people with a history of melanoma or atypical moles.
Contraindications
- xHistory of melanoma or skin cancer
- xFamily history of melanoma
- xLarge number of atypical moles
- xPregnancy or breastfeeding
- xSevere cardiovascular disease
GHK-Cu
Evidence Level
Strong preclinical (extensive animal studies)
FDA Status
Research compound
Safety Overview
GHK-Cu has an excellent safety profile backed by decades of research since its discovery in the 1970s. It's a naturally occurring peptide found in your blood, saliva, and urine—your body already knows it well. Concentrations naturally decline with age (from about 200 ng/mL at age 20 to 80 ng/mL by age 60), which is part of why supplementation makes sense. Most side effects are mild and injection-related. The copper component is well-tolerated at recommended doses but should be monitored in long-term use.
Contraindications
- xWilson's disease or copper metabolism disorders
- xKnown allergy to copper or peptide components
- xActive cancer or history of cancer
- xPregnancy or breastfeeding
- xChildren and adolescents
Decision Guide
Which is
right for you?
Choose Melanotan-2 if...
- Achieving a natural-looking tan
- Reducing sun exposure time
- Enhancing libido and sexual function
- Appetite suppression
Choose GHK-Cu if...
- Skin rejuvenation and anti-aging
- Wound and injury recovery
- Scar reduction
- Hair growth support