Per vial, USD
| Fill weight | 100+ | 1,000+ | 2,500+ | Order |
|---|---|---|---|---|
| 10 mg | $13.50 | $11.34 | $11.07 |
Ordering at volume
A cyclic peptide costs more to make than a linear one of the same length, and that is the fact to hold on to when a rate here is compared with a rate on a seven-residue linear chain. Once the chain is assembled the ring still has to be closed, and cyclization runs at high dilution so that chains react with themselves instead of with each other — a great deal of vessel occupied for a modest quantity of product. The purification that follows then has to separate closed material from whatever failed to close.
Fill weights on this line are confirmed at quote rather than published. The catalog row does not carry a figure we are prepared to print, so the vial size is agreed in writing before an order is placed and is restated on the quote and the packing list. Raise it explicitly on a first enquiry: a rate cannot be compared with another supplier's until both quotes name the same fill.
Everything else runs as standard catalog stock — held in California, quoted usually within the same business day, and priced on the quantity of this compound alone rather than on the order total. Because the vial size is settled at quote, the ladder is then applied to the vial count agreed there, which makes it sensible to fix the fill first and the quantity second. What a written quote restates back to you is described in how to order.
Specification
- Compound
- Melanotan II
- CAS number
- 121062-08-6
- Formula
- C₅₀H₆₉N₁₅O₉
- Molecular weight
- 1,024.18 g/mol
- PubChem CID
- 25054210
- Form
- Lyophilized powder, sealed vial
- Fill weights
- 10 mg
- Stock depth
- Standard catalog — Stocked in California. Each compound reaches its own tier break.
- Intended use
- Laboratory research only. Not for human or veterinary use.
What the material is
Melanotan II is a synthetic cyclic heptapeptide of the melanocortin class. Seven residues make up the chain, and the ring is closed not by the disulfide familiar from other cyclic peptides but by a lactam bridge — an amide bond formed between two side chains — with the chain ending in an amide rather than a free acid. The catalog lists it at 1,024.18 g/mol.
The ring is the defining structural fact and the thing that separates this molecule from an ordinary linear peptide of the same length. A closed ring is more rigid and has fewer routes by which it can come apart in solution than an open chain of seven residues. It arrives as an off-white freeze-dried solid, crimp-sealed in clear glass. Colour beyond a faint off-white cast, or a solid that has slumped away from the base, is worth raising before the carton is opened any further.
Storage and reconstitution
Hold the sealed vial in a −20 °C freezer, protected from light and moisture. The lyophilized solid holds up well at that temperature over long periods, and a short warm spell in transit does not compromise a vial that is still sealed and still shows an intact solid at the base.
It goes into a buffer appropriate to the assay, or into sterile water, and should give a clear solution. Hold that solution cold and dark and use it within a short window. The ring does not make a solution indefinitely stable, and repeated freeze-thaw cycles still cost material.
Buying questions
What fill weights does Melanotan II come in?
They are confirmed at quote rather than published. Our catalog row does not carry a fill figure we are willing to print, so the vial size is agreed in writing before the order goes ahead and appears on both the quote and the packing list. Ask for it on the first enquiry.
Why does a cyclic peptide cost more per vial than a linear one of the same length?
The ring has to be closed after the chain is built, and that step runs at high dilution so chains close on themselves rather than joining one another. It ties up a lot of vessel for a small amount of product, and the purification afterwards has to remove everything that did not close. Residue count alone does not predict the rate.
Does the ring change how a Melanotan II solution is stored?
No. A dissolved peptide is short-lived next to a sealed lyophilized vial whatever its shape, so the solution is kept cold, dark and aliquoted exactly as a linear peptide's would be.
What has to be agreed before a Melanotan II quote can be compared with another supplier's?
The fill, first of all. Two rates are not comparable until both name the same vial size, and this is the line where that detail is most often left vague. Get the fill, the quantity and the lot documentation stated in writing, then compare.
