How much water a 5 or 10 mg Melanotan II vial takes, and why a per-kilogram published dose makes the syringe reading depend on the person, not the vial.
Every reconstitution page on this site answers the same three questions: how much water, what concentration, how many units. Melanotan II is the compound where the third question has no single answer, because the only published human doses for it are stated per kilogram of body weight. The same vial, at the same concentration, reads as thirty units for one person and fifty for another. This page works the arithmetic through with weight as an explicit column, reports what the published figures are and where they came from, and records what the registry does and does not contain. It reports and does not recommend.
The Melanotan II calculator runs the same sums for any vial and volume, the sourced dose figures and their provenance are on the Melanotan II dosage page, and every compound's arithmetic is indexed on the reconstitution hub.
Water per vial and the concentration it gives
One U-100 unit is a hundredth of a millilitre.
| Vial |
Water |
Concentration |
One unit holds |
| 5 mg |
1 mL |
5,000 mcg/mL |
50 mcg |
| 5 mg |
2 mL |
2,500 mcg/mL |
25 mcg |
| 5 mg |
3 mL |
1,667 mcg/mL |
16.7 mcg |
| 10 mg |
1 mL |
10,000 mcg/mL |
100 mcg |
| 10 mg |
2 mL |
5,000 mcg/mL |
50 mcg |
| 10 mg |
3 mL |
3,333 mcg/mL |
33.3 mcg |
Nothing on this page is unusual so far; this is the ordinary table. What follows is where this compound differs from the rest of the set.
The column a calculator cannot fill in
The published human figure is 0.025 mg/kg. Converting it into micrograms requires a body weight, and converting that into syringe units requires the concentration as well. Both tables below use the 0.025 mg/kg figure from the two Wessells studies.
From a 10 mg vial:
| Body weight |
Amount at 0.025 mg/kg |
In 1 mL (10,000 mcg/mL) |
In 2 mL (5,000 mcg/mL) |
In 3 mL (3,333 mcg/mL) |
| 60 kg |
1,500 mcg |
15 units |
30 units |
45 units |
| 70 kg |
1,750 mcg |
17.5 units |
35 units |
52.5 units |
| 80 kg |
2,000 mcg |
20 units |
40 units |
60 units |
| 90 kg |
2,250 mcg |
22.5 units |
45 units |
67.5 units |
| 100 kg |
2,500 mcg |
25 units |
50 units |
75 units |
From a 5 mg vial:
| Body weight |
Amount |
In 1 mL (5,000 mcg/mL) |
In 2 mL (2,500 mcg/mL) |
In 3 mL (1,667 mcg/mL) |
| 60 kg |
1,500 mcg |
30 units |
60 units |
90 units |
| 70 kg |
1,750 mcg |
35 units |
70 units |
105 units — more than one syringe |
| 80 kg |
2,000 mcg |
40 units |
80 units |
more than one syringe |
| 90 kg |
2,250 mcg |
45 units |
90 units |
more than one syringe |
| 100 kg |
2,500 mcg |
50 units |
100 units — a full syringe |
more than one syringe |
The bottom right of the second table is the constraint most likely to be met in practice: a 5 mg vial in 3 mL is dilute enough that the published per-kilogram amount no longer fits in a single U-100 syringe. That is not an argument about what anyone should do; it is the point at which the arithmetic stops working and has to be redone at a different volume.
| Source |
Figure |
For a 70 kg adult |
In units from 10 mg in 2 mL |
| Dorr 1996, phase 1 starting dose (PMID 8637402) |
0.01 mg/kg |
700 mcg |
14 units |
| Dorr 1996, escalated (PMID 8637402) |
0.025 to 0.03 mg/kg |
1,750 to 2,100 mcg |
35 to 42 units |
| Wessells 1998 and 2000 (PMID 9679884, 11018622) |
0.025 mg/kg |
1,750 mcg |
35 units |
| Vendor pages, per this site's chart (2026-09-18) |
100 to 1,000 mcg, fixed |
100 to 1,000 mcg |
2 to 20 units |
The published human amounts sit above the circulating ones, which is the reverse of the pattern on most pages here. It is worth being precise about what that does and does not mean. The trial figures come from single doses and short courses given under direct observation — the phase 1 study ran weekdays for two consecutive weeks in three volunteers, and escalated one subject to 0.03 mg/kg where Grade II somnolence and fatigue appeared in one of two subjects at that level. They are not figures for repeated unsupervised use, and the studies did not test that. The vendor figures, for their part, have no study behind them that this site could locate.
How many amounts a vial holds
Set by the milligrams alone, unchanged by the water:
| Amount |
5 mg vial |
10 mg vial |
| 1,750 mcg (0.025 mg/kg at 70 kg) |
2, with 1.5 mg left |
5, with 1.25 mg left |
| 1,000 mcg |
5 |
10 |
| 500 mcg |
10 |
20 |
| 250 mcg |
20 |
40 |
What is not established
Melanotan II is not approved anywhere this site could verify. DailyMed returned no record for "melanotan" on 2026-09-21, checked alongside searches that did return results.
The registry position is more interesting than a count suggests. ClinicalTrials.gov holds exactly one Melanotan II registration, NCT07437560 — a phase 2 vitiligo study of 60 participants at Peking University Shenzhen Hospital, sponsored by Hudson Biotech, first posted on 27 February 2026 and recorded as recruiting. Its brief summary opens: "This example interventional study record describes a randomized Phase 2 clinical trial…". The record describes itself as an example. Its status field says recruiting, its phase field says 2 and its enrolment field says 60, and none of those fields carries any hint of the sentence that undoes them. Anyone counting registered trials for this molecule from the structured fields would report one; reading the summary gives zero.
The approved relative is worth knowing about for a different reason. Afamelanotide, sold as SCENESSE, is a subcutaneous implant — a solid rod placed under the skin, not a powder and not a solution. It has a current DailyMed label published on 13 May 2026 and 23 registered studies. The chemical family therefore does contain an approved product, and that product has no reconstitution arithmetic at all, because nothing about it is ever mixed with water.
The mechanism and the evidence file are covered in Medibact's Melanotan II guide. For the compound whose amounts run in the opposite direction — milligram doses a single vial barely covers — see the ARA-290 dosage page. For the general case of converting a published figure into what a syringe reads, the insulin syringe units guide sets out the arithmetic once.
