Melanotan II vs Somatropin

A side-by-side comparison from PeptideSciences101, the open peptide reference.

Overview

Melanotan II is primarily a cosmetic & skin peptide, while Somatropin is used for hormonal.

This page compares Melanotan II and Somatropin across their primary use, typical dosing, reported benefits and side effects, and U.S. regulatory status. For the full monograph on either compound — mechanism of action, clinical research, and references — follow the article links.

Side-by-side comparison

Melanotan IISomatropin
CategoryCosmetic & SkinHormonal
Regulatory status (US)Compounding (Rx) — Apr 2026FDA approved
Typical dosage250-500 mcg0.16-0.24 mg/kg/week (pediatric growth hormone deficiency); about 0.2 mg/day (adult growth hormone deficiency)
Frequencyas neededdaily subcutaneous injection
Reported benefitsSkin tanning without UV exposure, increased libido, potential appetite suppressionIn labeled use, somatropin increases linear growth in children with growth failure from growth hormone deficiency, Turner syndrome, Prader-Willi syndrome, small size for gestational age and idiopathic short stature. In adults with diagnosed growth hormone deficiency, professional guidelines describe benefits in body composition, exercise capacity, skeletal integrity and quality-of-life measures, with the largest benefit in the most severely deficient patients.
Reported side effectsNausea, facial flushing, darkening of moles, potential cardiovascular effectsFluid retention, edema, arthralgia and carpal tunnel syndrome are common in adults. Labeled warnings include glucose intolerance and new-onset diabetes, intracranial hypertension, slipped capital femoral epiphysis and scoliosis progression in children, hypothyroidism, hypoadrenalism, pancreatitis and hypersensitivity reactions.

Key differences

Primary use. Melanotan II is categorised under Cosmetic & Skin, while Somatropin falls under Hormonal. Their differing categories mean they are usually chosen for different goals rather than as direct substitutes.

Regulatory status. Melanotan II: not FDA-approved; compounding permitted with a prescription as of April 2026. Somatropin: FDA-approved.

Dosing. Melanotan II is typically dosed at 250-500 mcg (as needed). Somatropin is typically dosed at 0.16-0.24 mg/kg/week (pediatric growth hormone deficiency); about 0.2 mg/day (adult growth hormone deficiency) (daily subcutaneous injection).

Can you stack them?

Some protocols combine peptides, but stacking Melanotan II and Somatropin has not been validated for safety or efficacy in controlled trials. Combining compounds can change their effects and risks. Nothing here is medical advice — consult a qualified healthcare provider before starting or combining any protocol.

Frequently asked questions

What is the difference between Melanotan II and Somatropin?
Melanotan II is primarily a cosmetic & skin peptide, while Somatropin is used for hormonal. Melanotan II is not FDA-approved; compounding permitted with a prescription (as of April 2026), whereas Somatropin is FDA-approved for one or more indications.
What is Melanotan II used for?
Tanning, libido.
What is Somatropin used for?
Recombinant human growth hormone, FDA-approved for growth failure in children and growth hormone deficiency in adults.
Can you take Melanotan II and Somatropin together?
Some users combine peptides within a single protocol, but stacking Melanotan II and Somatropin has not been established as safe or effective in controlled trials. Neither this comparison nor PeptideSciences101 is medical advice — consult a qualified healthcare provider before combining any compounds.
Is Melanotan II or Somatropin FDA-approved?
Melanotan II is not FDA-approved; compounding permitted with a prescription (as of April 2026). Somatropin is FDA-approved for one or more indications.

Read the full articles

  • Melanotan II — full monograph: mechanism, research, dosing & references
  • Somatropin — full monograph: mechanism, research, dosing & references

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