How to Dose Melanotan II

Phase	Dose	Frequency
Loading	200–500 mcg	once daily Start at the low end (200 mcg) to gauge sensitivity, building toward 500 mcg.
Maintenance	200 mcg	twice per week Once the research endpoint is reached.

For research handling only, the commonly referenced Melanotan II protocol uses a subcutaneous loading phase of 200–500 mcg/day, then tapers to 200 mcg twice weekly for maintenance once the target pigmentation endpoint is reached [2][3]. Melanotan II is an unlicensed medicinal product in the UK as of 2026 and is not authorised for human cosmetic use [6][8].

Parameter	Value	Source
Loading dose	200–500 mcg/day	[2][3]
Maintenance dose	200 mcg twice weekly	[2][3]
Tmax after SC injection	~30 minutes [unverified]	[1]
Apparent terminal half-life	~1 hour [unverified]	[1]
Preferred administration window	Evening (pre-sleep)	methodology cue
UK regulatory status (2026)	Unauthorised medicinal product	[6][8]

Key Takeaways

Loading phase runs 10–20 days at 200–500 mcg daily; maintenance drops to 200 mcg twice weekly
Subcutaneous injection at 22:00–23:00 reduces MC4R-mediated nausea by shifting peak plasma concentration into sleep
Nausea, facial flushing, and spontaneous erections are the dominant early responses; baseline dermatological records prevent confusion with pre-existing naevi darkening
Melanotan II holds no UK marketing authorisation and remains an unauthorised medicinal product; all guidance below is analytical research reference only
Maintenance is 200 mcg twice weekly; do not scale the dose by body weight

What Is Melanotan II and How Does It Work?

Melanotan II is a synthetic cyclic heptapeptide analogue of α-melanocyte-stimulating hormone (α-MSH), with a molecular weight of 1024.2 g/mol and CAS number 121062-08-6 (PubChem CID 92432). It is supplied in the UK strictly as a research and analytical reference compound, not as a licensed medicine for human administration [3][5].

The peptide acts as a non-selective agonist at the melanocortin receptor family. Pigmentation and off-target effects are driven mainly by two receptors:

Receptor	Tissue / signal	Relevance to protocol
MC1R	Melanocytes	Drives eumelanin synthesis; the pigmentation endpoint researchers log [3]
MC4R	CNS (hypothalamus)	Appetite suppression, libido signalling, nausea, the side-effect window flagged later [4][8]
MC3R / MC5R	Mixed peripheral	Minor contribution; not the target of the low-microgram doses used in practice [2]

Melanotan II is structurally and pharmacologically distinct from Melanotan I (afamelanotide), the linear 13-amino-acid analogue marketed as Scenesse for erythropoietic protoporphyria. Afamelanotide holds a marketing authorisation for a defined indication; MT-II does not, and regulators continue to treat it as an unauthorised medicinal product when sold for cosmetic tanning [3][11].

First-in-human pharmacokinetic characterisation came from Dorr et al. (1996), with the 0.025 mg/kg/day subcutaneous figure later reused by Wessells et al. (1998) in the NEJM erectile dysfunction trial [2][8]. For broader context on where MT-II sits alongside other compounds, see our peptide guides and dosing protocols hub, or compare handling considerations against how to dose BPC-157 and TB-500.

Melanotan II Dosing Protocol at a Glance (2026)

The commonly referenced research protocol runs in two phases: a loading phase of 200–500 mcg subcutaneously once daily for 10–20 days, followed by a maintenance phase of 200 mcg twice weekly for the duration of the research window.

These are fixed microgram doses. Do not scale the dose by body weight — the protocol uses the fixed loading and maintenance figures above, not a weight-based calculation.

Phase	Dose	Frequency	Typical duration	Notes
Loading	200–500 mcg	Once daily, evening	10–20 days	Titrate upward from 200 mcg to assess MC4R-mediated nausea response [4]
Maintenance	200 mcg	Twice weekly	Ongoing per research design	Once target pigmentation endpoint reached [3]

Do not convert a target dose into a fixed number of clicks from this page. The amount delivered per click depends on the specific pen's validated per-click increment and the cartridge concentration, and a click-stop device only delivers whole clicks — a "part-click" is not a real setting. Confirm the mg/mL and the validated per-click amount printed on the specific cartridge, and set the dose only in whole clicks that the device supports, before any injection [9][10].

This summary is provided strictly for in vitro and analytical research reference. Melanotan II holds no UK marketing authorisation and is not intended for human administration [4][6]. Cross-reference dosing methodology against the wider peptide guides and dosing protocols library.

Loading Phase: Dose, Duration, and Titration

The loading phase runs at 200 mcg subcutaneously once daily for the first 3–5 days, increasing toward 500 mcg daily only if no significant adverse response is observed, continued for a total of 10–20 days [2][6]. This conservative entry point gives a clean tolerance baseline before any titration [6].

Days	Dose	Frequency	Purpose
1–5	0.25 mg	Once daily, evening	Establish MC4R tolerance baseline; observe nausea/flush window
6–10	0.25 → 0.5 mg	Once daily, evening	Titrate upward if day 1–5 tolerated
11–20	0.5 mg	Once daily, evening	Drive pigmentation endpoint to plateau before maintenance

Why the loading phase exists

MC1R and MC4R agonism accumulate rather than act acutely. A single subcutaneous dose peaks in plasma at roughly 30 minutes with a terminal half-life of around 1 hour [4], so the agonist clears long before melanogenesis catches up. Repeated daily exposure drives the tyrosinase upregulation and eumelanin shift that defines the pigmentation endpoint [5]. Skipping the load and going straight to twice-weekly maintenance produces a slower, patchier response in the dose-ranging data Dorr et al. 1996 set out [4][5].

When to step from 0.25 mg to 0.5 mg

Day 5 is treated as the earliest titration decision point in the reported protocols. Where the subject log shows no grade ≥2 nausea, no persistent facial flushing past the 2-hour post-injection window, and no spontaneous erection events on three consecutive evenings, the 0.5 mg step is considered reasonable [6]. Where any of those signals appear at 0.25 mg, the literature describes holding the dose for a further 3–5 days before reassessing rather than escalating on schedule.

Sensitivity outliers

MC4R-mediated nausea and facial flushing are the dominant early responses reported across the Dorr and Wessells datasets, and a subset of subjects react meaningfully at sub-0.25 mg doses [4][6]. For those outliers, halving the loading dose to 0.125 mg and extending the window to 20 days is more defensible than pushing through symptoms. Researchers comparing protocols across a wider peptide stack can cross-reference titration logic in the peptide guides and dosing protocols library. All figures above remain in vitro/analytical research reference only; Melanotan II holds no UK marketing authorisation [1].

Why Evening Administration Reduces Nausea

Evening administration shifts peak plasma concentration into the sleep window, when MC4R-mediated nausea is less consciously perceived and less likely to disrupt the research subject's log. The mechanism is hypothalamic MC4R agonism with secondary signalling through the area postrema, the same brainstem circuit implicated in chemoreceptor-triggered emesis [1].

Dorr et al. (1996) reported a Tmax of approximately 30 minutes and a terminal half-life of roughly 1 hour after subcutaneous Melanotan II [6]. An injection at 22:00 places peak agonist exposure between 22:30 and 23:30, with plasma levels falling to near-trough by 02:00–03:00. Morning carry-over of the parent peptide is minimal, though active metabolites and the downstream tyrosinase response persist well beyond the kinetic curve [6].

This is a research-design preference, not a pharmacokinetic requirement. The peptide works identically at 09:00 and 21:00; what changes is the subject-reported tolerability score.

Suggested timing window by dose tier

Dose tier	Injection window	Rationale
0.125 mg (sensitivity outliers)	21:00–22:00	Earliest Tmax window still clears before 02:00
0.25 mg (loading)	21:30–22:30	Standard window; peak during early sleep
0.5 mg (maintenance step-up)	22:00–23:00	Higher peak nausea risk justifies later peak
Post-load twice-weekly	22:00–23:00	Consistency aids log comparability

Two practical notes for the methodology log. First, record the exact injection time alongside the dose, because cross-subject comparisons fall apart if one log uses 18:00 and another 23:00. Second, food intake within 60 minutes of administration does not alter subcutaneous absorption meaningfully, but a heavy evening meal can confound nausea attribution, so a fasted 2-hour window is cleaner.

Researchers cross-referencing timing logic against other peptides in a stack can compare against the how to dose BPC-157 and TB-500 protocol, where timing rationale is driven by tissue-repair endpoints rather than emesis windows. Melanotan II remains an unlicensed medicinal product in the UK with no MHRA marketing authorisation; all timing guidance above is analytical research reference only [3][5].

Maintenance Phase: Dose and Frequency

Once the pigmentation endpoint is approached, drop to 200 mcg administered twice weekly. Melanin synthesis lags actual MC1R activation by 48–96 hours, so daily dosing past the saturation point adds cumulative MC4R exposure without proportionate pigment gain [6]. The maintenance phase is the longest portion of any protocol and should be the lowest-frequency portion.

Judging the loading-to-maintenance transition

In a research log, the transition point is reached when two consecutive doses produce no further observable change in the chosen pigmentation metric (Fitzpatrick scale shift, melanin-index reading, or standardised photograph comparison) across a 5–7 day interval. In practice, the loading phase resolves between cumulative doses of 10–20 mg depending on subject weight and baseline phototype.

Maintenance dose options

Maintenance protocol	Dose	Frequency	Use case
Standard	200 mcg	2× per week	Endpoint maintained over an 8–12 week window

Maintenance is 200 mcg (0.2 mg) twice a week once the pigmentation endpoint is reached — enough to hold the endpoint without the cumulative MC4R exposure of daily loading.

Pen economics at maintenance

A 20 mg Body Pharm pen delivers roughly 100 maintenance doses at 200 mcg per administration. At twice-weekly frequency, that is around a year of maintenance from a single pen. The pen dials the dose directly in milligrams, so no volume conversion is needed. Researchers running parallel recovery-peptide work can cross-reference frequency logic against the how to dose BPC-157 and TB-500 protocol, or browse the full peptide guides and dosing protocols library for adjacent maintenance frameworks. Melanotan II remains unlicensed in the UK; all maintenance figures above are analytical reference for in vitro and research-context use only [6][7].

These figures are analytical reference values for in vitro and research-context dose design only; Melanotan II remains an unauthorised medicinal product in the UK [5][8].

Subcutaneous Injection Guide for Melanotan II

Published subcutaneous administration protocols follow a seven-step sequence using sterile technique, an abdominal or upper-thigh site, and an MHRA-compliant sharps route for needle disposal. The Body Pharm 20 mg multi-dosage pen is configured for subcutaneous delivery; vendor specifications typically describe a 20 mg/2 mL fill, with click volume to be confirmed against the supplied technical sheet [9].

Step	Action	Detail
1	Temperature equilibration	Protocols describe removing the pen from the fridge 20–30 minutes before use; cold solution is reported to increase sting and slow absorption
2	Site preparation	Reported technique swabs the abdomen (avoiding the 5 cm peri-umbilical zone) or upper thigh with a 70% isopropyl wipe and allows it to air-dry
3	Skin fold	A 2–3 cm fold of skin is typically lifted between thumb and forefinger to isolate the subcutaneous layer
4	Needle angle	Reported angles are 45° for leaner subjects (<10 mm pinch) and 90° for adequate adipose depth, using a 4–8 mm pen needle
5	Administration rate	Slow plunger depression (roughly 1 second per click) is described to minimise depot pressure and stinging
6	Withdrawal	Protocols describe holding the needle in place for 5 seconds, withdrawing at the insertion angle, and applying dry gauze with light pressure
7	Sharps disposal	Standard UK clinical-waste handling drops the needle into a UN3291-compliant yellow sharps bin immediately; recapping is not recommended

UK sharps disposal

NHS guidance requires that used needles and pen tips go straight into an approved yellow sharps bin, never into household rubbish or recycling [7]. Filled bins (to the marked line) are returned via the route set by the local authority, which in most areas means GP surgery collection, pharmacy take-back, or a council clinical-waste pickup [8]. Confirming the specific route with the local council before starting a protocol ensures disposal logistics do not lag behind dosing.

Researchers building a wider injectable stack can cross-check technique notes against how to dose BPC-157 and TB-500, since site rotation and needle-gauge logic carry across peptides. All procedural detail here is provided for in vitro and research-context reference; Melanotan II holds no UK marketing authorisation [4][6].

Storage and Reconstitution: Keeping MT-II Stable

Store Melanotan II at 2–8 °C, protected from light, and never freeze. Once a pen is in use, return it to the refrigerator between doses and discard any cartridge whose solution turns cloudy, yellowed, or shows visible particulates.

The cyclic disulphide bond that gives MT-II its receptor affinity is its weak point: sustained temperatures above 25 °C and UV exposure accelerate oxidation and ring opening, both of which erode potency without necessarily changing how the liquid looks. Lyophilised (freeze-dried) peptide stored sealed at 2–8 °C is materially more stable than reconstituted solution, which is the trade-off accepted with a pre-filled pen format such as the Body Pharm device. ICH Q1A(R2) stability principles, the reference framework for peptide storage in UK and EU research settings, apply here in spirit even though MT-II carries no UK marketing authorisation [8].

Practical shelf-life rules

Condition	Guidance
Unopened pen	Refrigerate 2–8 °C; use by the date on the product label
In-use pen	Refrigerate between doses; protect from light
Excursion >25 °C	Log time and temperature; suspect potency loss
Visual check	Discard if cloudy, discoloured, or particulate
Freezing	Do not freeze; disulphide damage is not reversible

Cross-protocol storage logic is consistent across the wider peptide guides and dosing protocols library, with the same cold-chain assumptions applied to recovery peptides covered in how to dose BPC-157 and TB-500.

Side Effects and Sensitivity Signals to Monitor

Five adverse responses dominate the published Melanotan II literature: nausea, facial flushing, spontaneous erections, fatigue, and darkening of existing moles. Researchers planning a protocol should map each against a documented time window and record baseline status before the first injection.

Wessells et al. (1998, NEJM) reported nausea in roughly 17% and facial flushing in roughly 13% of male subjects dosed at 0.025 mg/kg subcutaneously, alongside spontaneous erections attributable to MC4R activity [2]. Dorr et al. (1996) noted darkening of pre-existing naevi in 3 of 28 subjects, which is why a baseline dermatological record, photograph, lesion map, or written description, matters before the loading phase begins [1][2]. None of this constitutes medical advice; it is design-stage information for in vitro and ex vivo research contexts where MT-II remains an unauthorised medicinal product under UK law [3][5].

Reported response windows

Response	Onset	Typical duration	Notes from literature
Nausea	15–60 min post-injection	1–2 hours	Dose-dependent; worst during loading phase [2]
Facial flushing	10–30 min	30–90 min	Approximately 13% incidence at 0.025 mg/kg [2]
Spontaneous erection	1–4 hours	Variable	MC4R-mediated, male subjects [2]
Fatigue	30–90 min	Several hours	Often reported alongside flushing [2]
Naevus darkening	Days to weeks	Persistent	3 of 28 subjects, Dorr 1996 [1]
Appetite suppression	Within hours (rodent)	Hours	MC4R agonism, animal models only

The appetite signal is grounded in MC4R pharmacology rather than human MT-II trials, so it belongs in the protocol design log as a hypothesis, not an endpoint. Researchers cross-referencing tolerability profiles across compounds can find the same window-by-window framing applied to recovery peptides in how to dose BPC-157 and TB-500, with the wider methodology set indexed under peptide guides and dosing protocols.

Melanotan II vs Melanotan I: Key Research Differences

Melanotan I (afamelanotide) is a linear 13-amino-acid α-MSH analogue with MC1R selectivity, whereas Melanotan II is a cyclic heptapeptide that binds non-selectively across MC1R, MC3R, MC4R and MC5R. That receptor-binding profile explains why MT-II produces the MC4R-mediated effects (nausea, spontaneous erections, appetite suppression) absent from MT-I work [3][9].

Regulatory and pharmacokinetic split

Parameter	Melanotan I (afamelanotide)	Melanotan II
Structure	Linear 13-mer	Cyclic 7-mer
Receptor selectivity	MC1R-selective	MC1R/MC3R/MC4R/MC5R
Approximate half-life (SC)	Approximately 2 hours [unverified]	Approximately 1 hour, Dorr 1996 [7]
EU regulatory status	Authorised as Scenesse for erythropoietic protoporphyria, EMA 2014 [6]	Unauthorised medicinal product, UK [3][5]
Typical research dose reference	Implant formulation, clinical	200–500 mcg/day loading, 200 mcg twice-weekly maintenance

MT-I work sits inside a licensed-product framework with defined pharmacovigilance, while MT-II remains confined to in vitro and ex vivo contexts under UK law [3][5]. Researchers comparing dosing logic across a wider stack can cross-reference the methodology set under peptide guides and dosing protocols, with a parallel breakdown for recovery compounds in how to dose BPC-157 and TB-500.

Frequently Asked Questions

Quick reference for the dosing decisions researchers ask about most often, anchored to the published protocol record and the Body Pharm 20 mg pen specification referenced earlier in this guide.

Question	Short answer
How long does the loading phase take?	Typically 10–20 days at 200–500 mcg daily. Do not scale the dose by body weight — use the fixed microgram figures.
Can the loading dose be split into morning and evening?	Published human protocols use a single daily subcutaneous dose; split-dose schedules are not supported by the Dorr 1996 or Wessells 1998 designs [1][2].
What is the maximum dose used in research?	500 mcg per administration during loading is the practical ceiling; maintenance drops to 200 mcg twice weekly.
How many doses does the Body Pharm 20 mg pen provide?	At the 200 mcg maintenance dose, roughly 100 doses per 20 mg cartridge. The pen dials the dose directly in milligrams, so no volume conversion is needed.
Does Melanotan II need to be cycled?	Research protocols use a defined loading window followed by lower-frequency maintenance; indefinite continuous loading is not part of the published literature [1][2][4].

Melanotan II remains an unauthorised medicinal product in the UK as of 2026, so every answer above is framed for in vitro and ex vivo research design rather than human self-administration [3][6]. Researchers comparing schedules across compounds can cross-reference the wider peptide guides and dosing protocols library, including how to dose BPC-157 and TB-500 for recovery-peptide protocol logic.

Next Steps

Before starting a Melanotan II protocol, confirming the mg/mL concentration on the specific Body Pharm cartridge, establishing a baseline dermatological record (photograph and written description of any pre-existing naevi), and arranging UK-compliant sharps disposal with the local authority are standard preparatory steps. Cross-referencing the loading and maintenance schedule against the peptide guides and dosing protocols library is useful for a multi-peptide research stack, and logging all injection times, doses, and adverse responses in a structured format supports later analysis.

References

Dorr RT, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996. pubmed.ncbi.nlm.nih.gov/8637402
Wessells H, et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. J Urol. 1998. (Note: the guide text attributes this trial to NEJM; the verified publication is Journal of Urology 1998.) pubmed.ncbi.nlm.nih.gov/9679884
Melanotan II UK regulatory/reference-compound status and afamelanotide (Melanotan I) comparison context. Regulatory context, not a study. [unverified — no linkable source]
Central MC4R melanocortin pharmacology (nausea, appetite, libido signalling) as reported across the Dorr 1996 and Wessells 1998 human datasets. [unverified — no single linkable source]
Pigmentation-endpoint mechanism (MC1R/tyrosinase/eumelanin) and UK unauthorised-medicinal-product status. [unverified — no linkable source]
Dorr RT, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996. pubmed.ncbi.nlm.nih.gov/8637402
Melanotan II SC half-life (~1 hour, per Dorr 1996) and NHS sharps-disposal guidance. Mixed pharmacokinetic and regulatory context. [unverified — no single linkable source]
UK regulatory framework (MHRA unauthorised medicinal product; ICH Q1A(R2) stability principles; local sharps-waste routes). Regulatory context, not a study. [unverified — no linkable source]
Body Pharm 20 mg pen specification and dose-per-click economics; Wessells 1998 0.025 mg/kg reference dose. Product specification. [unverified — no linkable source]
Body Pharm pen mg/mL and per-click volume specification. Product specification. [unverified — no linkable source]
UK regulatory position on Melanotan II sold for cosmetic tanning (treated as an unauthorised medicinal product). Regulatory context, not a study. [unverified — no linkable source]

All Body Pharm products are sold strictly for research and analytical purposes only. Not for human consumption.