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Melanotan-2 Dosage: 100mcg → 500mcg Loading Chart (2026)

Affiliate disclosure: vendor links in this article are affiliate links — The Peptide Catalog may earn a commission if you buy through them, at no additional cost to you. Where These Numbers Come From MT-2 has some human clinical data, primarily from sexual dys

By Recovery & Performance Peptides Editorial Team

Affiliate disclosure: vendor links in this article are affiliate links — The Peptide Catalog may earn a commission if you buy through them, at no additional cost to you.

Where These Numbers Come From

MT-2 has some human clinical data, primarily from sexual dysfunction studies rather than tanning.

Wessells et al. (2000) tested intranasal MT-2 at 0.025 mg/kg (approximately 1.75 mg for 70 kg person) in a Phase II erectile dysfunction trial with significant efficacy (PMID 11035391). Dorr et al. (1996) published the Phase I clinical study of MT-II demonstrating melanotropic activity (PMID 8637402).

The loading/maintenance pattern evolved from decades of underground use: early protocols (1990s) used higher doses with more side effects; current protocols have been refined through community experience. The community settled on 250-500 mcg range as the sweet spot for effective MC1R saturation without excessive nausea.

Stacking Protocols

MT-2 is rarely stacked due to its unique mechanism and side effect profile.

UV exposure

500 mcg per protocol

Essential — not optional

Sun protection

Standard

MT-2 tan does NOT eliminate need for SPF

Community sources describe MT-2 and PT-141 as redundant rather than synergistic, since both work through melanocortin receptors — typically one is chosen based on the primary goal (tanning vs sexual enhancement). Community sources similarly describe MT-2 and Melanotan-1 as redundant overlap rather than a complementary stack.

Side Effects & Safety

Nausea — community sources report 80-90% of users experience it during loading, especially at higher doses. Peaks 2-4 hours post-injection, lasts 4-6 hours. Community sources describe bedtime dosing to minimize impact

Facial flushing — within 30-60 minutes, lasts 1-2 hours

Appetite suppression — community sources describe reductions exceeding 50% during the loading phase

Libido increase — pronounced; led to PT-141 development

Fatigue/lethargy — especially first week

Mole/freckle darkening — potentially permanent; community and clinical sources describe dermatological monitoring for these changes, especially with long-term use

Injection site darkening — localized hyperpigmentation

Mood changes — irritability reported by some during loading

Managing nausea: community sources commonly describe beginning at 100-250 mcg, injecting before bed on an empty stomach, using anti-nausea medication (ondansetron) when needed, and escalating the dose gradually.

mg to Units Conversion

On a standard 100-unit insulin syringe, each "unit" equals 0.01 mL (so 100 units = 1 mL). Once Melanotan-2 is reconstituted, the conversion from a target dose to syringe units depends on the chosen dilution.

The two reconstitution ratios most often described in community protocols are below.

Reconstitution A: 10 mg vial + 2 mL BAC water (5 mg/mL) — the standard dilution from the Quick Reference above.

250 mcg

0.05 mL

5 units

500 mcg

0.1 mL

10 units

750 mcg

0.15 mL

15 units

1000 mcg

0.2 mL

20 units

Reconstitution B: 10 mg vial + 3 mL BAC water (3.33 mg/mL) — more BAC water for larger, easier-to-measure draws.

0.075 mL

7.5 units

0.225 mL

22.5 units

0.3 mL

30 units

These conversions reflect the dilutions documented in community reconstitution protocols. They report how the math is described, not a recommended dosing schedule.

Core Supplies for This Protocol

The three essentials for running any reconstituted injectable: cold storage, accurate syringes, and metabolic tracking.

Cooluli Classic 4L Mini Fridge

Compact thermoelectric mini-fridge with heat/cool toggle. The most-mentioned dedicated peptide-storage fridge in research community sources — fits ~20 vials and runs quietly.

BD Ultra-Fine 31G 0.3cc 5/16" Insulin Syringes (Box of 90)

0.3cc 31G syringes — each gradation marks 1 unit (vs 2 units on 1cc), making sub-50-unit peptide doses accurate. BD Ultra-Fine is the most widely-cited brand in peptide community sources.

CONTOUR NEXT GEN Glucose Meter All-In-One Kit

Ascensia's CONTOUR NEXT GEN — the most clinically-validated home glucose meter. Includes 20 test strips + lancing device. Tracks the blood-sugar response GLP-1 users care about, especially during dose escalation.

As an Amazon Associate, The Peptide Catalog earns from qualifying purchases.

CONNECTED / MODULES

Post-session references

Selected from shared article topics. Source links are retained where available.

01

Handling & safety lane

Source-derived education, not individual medical guidance or an instruction to dose.

DOSAGE SOURCE

The Unfiltered Truth About Melanotan-2 Dosing Economics

Here's the honest answer: most melanotan-2 protocols circulating online are designed to sell more peptide, not to optimize outcomes. The 'front-load with 1mg daily for a week' approach has no basis in the published pharmacology and directly contradicts the receptor occupancy data from clinical trials. Receptor saturation doesn't care about loading. It cares about cumulative occupancy over time, which 250mcg every 72 hours achieves just as effectively as 1mg daily but with 75% less peptide consumption and a fraction of the side-effect burden. The loading myth persists because it moves inventory. A user buying 50mg of peptide and running 1mg daily depletes supply in seven weeks versus 20 weeks on a maintenance protocol. We mean this sincerely: if your supplier recommends daily milligram-range dosing or claims you need to 'saturate receptors quickly,' they either don't understand melanocortin pharmacodynamics or they're prioritizing revenue over protocol integrity. The University of Arizona trials that established melanotan-2's tanning efficacy used 250mcg doses at 48–72 hour intervals because the researchers understood that melanogenesis is a multi-day process. Tyrosinase upregulation, melanosome maturation, and eumelanin polymerization take 48–96 hours per cycle. Injecting daily doesn't accelerate that timeline. It just stacks peptide in plasma while melanocytes are still processing the previous dose. The melanotan-2 myths cost money health dynamic is most visible in reconsti…
SIDE EFFECTS

Side Effects, Contraindications, and Risk Mitigation Strategies

The most common side effects during MT2 loading phase are nausea (40–60% of users), facial flushing (30–50%), and spontaneous erections in males (20–40%). These effects result from non-selective melanocortin receptor binding. Nausea from MC4R activation in the hypothalamus, flushing from peripheral vasodilation, and erections from MC4R in the paraventricular nucleus. Side effects peak 2–4 hours post-injection and resolve within 6–8 hours as plasma peptide levels decline below receptor activation threshold. Nausea mitigation: Start at 250mcg for the first 3–5 doses, inject post-meal rather than fasted, split daily dose into two 250mcg injections 8–12 hours apart, or administer before bed so nausea occurs during sleep. Over-the-counter anti-nausea agents like meclizine (25mg) or ginger extract (500mg) taken 30 minutes pre-injection reduce symptom severity in clinical observation. Most users develop tolerance by day 7–10 as MC4R receptors downregulate in response to chronic agonist exposure. Unexpected darkening of existing moles and freckles occurs universally. MT2 stimulates melanin synthesis in all melanocytes, not just those in previously untanned skin. New mole formation has been reported in case studies but remains unquantified in controlled trials. Users with dysplastic nevus syndrome or personal/family history of melanoma should avoid MT2 entirely due to theoretical risk of accelerating malignant transformation in pre-existing atypical melanocytes. Appetite suppression …
02

Question drills

Open a question for its connected answer.

01What If the Research Goal Is to Model Human Sexual Dysfunction Therapies?+

Rodent models are insufficient. Non-human primates are required. MT-II's erectile effects in rats occur via hypothalamic MC4R activation of oxytocinergic neurons projecting to the spinal cord, but primate central nervous system architecture differs significantly. The compound bremelanotide (PT-141), a derivative of MT-II, advanced to human trials specifically because rhesus macaque studies demonstrated dose-dependent sexual arousal responses that translated to human physiology. If rodent models must be used, combining MT-II with PDE5 inhibitors allows separation of central arousal (melanocortin-mediated) from peripheral erectile mechanisms (cGMP-mediated).

SOURCE / realpeptides.co ↗
02What If You're Considering Long-Term Maintenance Dosing?+

Understand that you're participating in an uncontrolled experiment. There is no published data tracking outcomes beyond 16 weeks. If you proceed, document baseline dermatoscopic images, blood pressure, lipid panel, and testosterone/LH levels before starting. Recheck at 3-month intervals. The absence of data doesn't mean the compound is safe. It means risk is unknown.

SOURCE / realpeptides.co ↗
03What If I Left Unreconstituted Melanotan-2 Out for 24 Hours?+

Return the vial to −20°C storage immediately. If the powder shows no colour change and was sealed throughout, potency loss is likely under 5%. Use it normally. The brief excursion at typical room temperature falls within the peptide's tolerance window for lyophilised stability.

SOURCE / realpeptides.co ↗
04What If a Lab Wants to Study Melanocortin Pathways but Needs MC1R Selectivity?+

Consider the MT2-Δ4 analogue characterised in the University of Arizona study published in Peptides (April 2026), or contact peptide synthesis facilities capable of custom amino-acid substitutions at positions 4, 7, and 10 of the cyclic scaffold. Melanotan-2 itself will activate MC4R at the same concentrations that drive melanogenesis, making it unsuitable for isolating MC1R-specific effects. Alternatively, alpha-MSH (the endogenous ligand) shows modest MC1R preference but has a plasma half-life under 10 minutes, requiring continuous infusion in cellular models. For experiments requiring sustained MC1R activation without MC4R cross-talk, a custom analogue is the only viable approach.

SOURCE / realpeptides.co ↗
05What If I Don't See Any Darkening After One Week of Daily Dosing?+

Administer a test dose of 0.5mg and monitor for nausea or flushing within 30–60 minutes. These are systemic markers of peptide activity. If you experience nausea but no pigmentation by day 7, the issue is likely melanocyte density (Fitzpatrick type I skin with minimal baseline melanin) or MC1R gene polymorphisms reducing receptor sensitivity. If you experience no nausea and no pigmentation, suspect peptide degradation from improper storage. MT-2 must be stored at 2–8°C after reconstitution and used within 30 days. Lyophilised powder stored above 25°C for extended periods loses potency irreversibly.

SOURCE / realpeptides.co ↗
03

Evidence cooldown

Research context and source excerpts for a slower second read.

RESEARCH

15. UK research-grade sourcing standards

MT-II should be sourced with full documentation: ≥98% HPLC purity (≥99% is the emerging 2026 standard) Mass spectrometry identity confirmation Batch-specific Certificate of Analysis Endotoxin quantification Residual TFA analysis Cyclisation integrity confirmation (LC-MS distinguishing cyclic from linear isomers) C-terminal amide confirmation (critical distinction from PT-141 free carboxyl) Lyophilised powder with cold-chain shipping Quality-control note: MT-II and PT-141 are near-identical in amino acid sequence. An inadequately QC’d batch of MT-II could be contaminated with PT-141 or the reverse. Mass spectrometry distinguishes the two (MT-II MW 1024 Da; PT-141 MW 1025 Da — 1 Da difference corresponding to amide→carboxyl). A high-quality COA should specifically confirm the expected MW.

RESEARCH

Summary: Melanotan 2 in Neurological Research

MT-II engages CNS biology through two primary receptor systems with distinct mechanistic profiles: MC1R on microglia drives cAMP-PKA-CREB-mediated NF-κB suppression and anti-neuroinflammatory M2-polarising effects across TBI, SCI and stroke models; MC4R on hippocampal and hypothalamic neurones mediates direct neuroprotection, enhanced LTP, BDNF upregulation, dendritic spine density increases, and cognitive enhancement in spatial memory paradigms. In neurodegenerative models (APP/PS1 AD mice, 6-OHDA partial dopamine depletion), these complementary mechanisms converge to produce synaptotrophic, anti-inflammatory and amyloid clearance-related effects. Hypothalamic MC4R circuitry additionally provides research access to energy homeostasis and autonomic regulation biology. The mechanistic diversity of MT-II’s CNS profile makes it a versatile tool compound for investigating melanocortin receptor pharmacology across neurological research domains. William is a research analyst at Peptides Lab UK, specialising in research peptides, laboratory compounds, and sourcing standards for high-purity peptide products.

05

Product & matchup locker

Linked catalog and comparison files.

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