RQS Scoring Log

Melanotan II

Sexual Health· Observational· Scored June 2026· View compound profile →

38 /100

Weak Evidence

7 dimensions · 100 points total · Methodology by PeptideClear

Dimension Breakdown

Dimension	Scoring Notes	Score
Study Design	Phase I and Phase II human trials exist for both tanning (melanogenesis) and erectile dysfunction indications — conducted primarily at University of Arizona. Genuine human trials with controlled designs. However, development was abandoned before Phase III, so no completed efficacy RCT exists. Phase I/II score of 10 is accurate.	10 / 25
Sample Size	Phase I trials enrolled 10–30 subjects. The Wessells 1998 erectile dysfunction study enrolled ~10 men. Dorr 1996 tanning study enrolled small cohorts. Cumulative human sample is in the low tens — typical Phase I sizing but thin for evidence purposes.	4 / 20
Replication	University of Arizona (Hadley group) conducted the primary human trials — single research group essentially. Some independent melanocortin receptor pharmacology work exists but specific MT-II human replication outside Arizona is minimal. Partial credit for mechanistic replication via PT-141 successor literature.	5 / 20
Journal Impact Factor	Wessells 1998 published in Urology (IF ~2.5); Dorr 1996 in Archives of Dermatology (IF ~4.5 at time); Van der Ploeg melanocortin review in higher-tier pharmacology journals. Mix of mid-tier to decent specialty journals.	8 / 15
Funding Independence	University of Arizona and NIH-funded academic research for original development. Genuinely independent academic origin — not industry-sponsored trials. Deduction for limited scope and single-institution concentration.	7 / 10
Population Diversity	Small Phase I cohorts, predominantly white male (erectile dysfunction studies) or limited demographic reporting. Narrow population base.	1 / 5
Researcher h-Index	Mac Hadley (University of Arizona, original MT-II developer) has a credible academic profile in melanocortin biology but h-Index is moderate in modern databases. Victor Hruby (peptide chemistry, UA) has a stronger profile (h-Index ~60+) but his contribution is to the chemistry, not clinical trials. Blended score reflects mixed investigator profiles.	3 / 5

Animal Only Note

This score reflects evidence in humans. Animal and in vitro evidence — particularly rodent melanocortin behavior and tanning models — is substantially stronger than the human score suggests. MT-II has not progressed to Phase III human trials; development was redirected to PT-141 (bremelanotide), which reached FDA approval in 2019.

Sources: PubMed — Dorr et al. 1996 Arch Dermatol (PMID 8794166), Wessells et al. 1998 Urology (PMID 9655544), Van der Ploeg et al. 2002 melanocortin pharmacology. Lead researchers: Mac Hadley, Victor Hruby (University of Arizona). Funding: NIH/academic — independent origin.

Note: MT-II development was abandoned in favor of PT-141 (bremelanotide), which reached FDA approval in 2019 for HSDD. The human trial base is intentionally thin because commercial development stopped at Phase II. Regulatory status: no approval in US, EU, UK, or Australia — sold as an unregulated research chemical. Melanocytic nevus darkening and mole-change reports represent a genuine unresolved safety concern.

Scored by the PeptideClear editorial team using publicly available literature. Sources: PubMed (study design, sample size, replication) · ScimagoJR (journal impact factor) · Google Scholar (researcher h-Index) · Primary papers (funding disclosure). Scores are reviewed as new research is published.