PHG · REV 2026.10 For laboratory research use only. Not medical or dosing guidance.
Peptide Handling Guide Storage, handling and documentation for research peptides
Document
CS-SEMAX
Type
Compound handling sheet
Revised
Sources checked
Bands
−20 °C

Semax Handling Sheet

Also known as ACTH(4–7)-Pro-Gly-Pro, Met-Glu-His-Phe-Pro-Gly-Pro

A seven-residue peptide built on the ACTH(4–7) fragment with a Pro-Gly-Pro extension. Its N-terminal methionine is the main stability concern.

1 min read

Identity

Sequence
MEHFPGP
Formula
C37H51N9O10S
Molecular weight
813.9 g/mol (average)
Usual supplied form
Lyophilized powder
Record
PubChem

M oxidation-prone N deamidation-prone D Asp-Gly / Asp-Ser site

Formula and weight are for the free peptide. Salt forms (acetate, TFA) weigh more; use the figure on the lot's COA.

Storage & sensitivity

Lyophilized−20 °C
In solution−20 °C
Oxidation
High
Light
Moderate
Moisture
Moderate
Inferred from structure

Little compound-specific stability data is published. Guidance follows from the sequence and general peptide chemistry.

Bench card

  • Met1 oxidizes readily; minimize oxygen exposure and use degassed solvent.
  • His3 is also oxidation-prone, especially with trace metals or light.
  • Store solutions as frozen aliquots; −80 °C for longer holds.
  • The C-terminal Pro-Gly-Pro was added to slow enzymatic breakdown, not chemical degradation.
  • Storage advice here is inferred from sequence chemistry; no published shelf-life study was found.

Handling-relevant features

FeatureWhy it matters for handling
Met1Oxidizes to methionine sulfoxide (+16 Da)
His3Susceptible to metal-catalyzed and photosensitized oxidation
Phe4Weak UV absorber; contributes modestly to light sensitivity
Pro-Gly-Pro C-terminusAdded to resist peptidases in biological systems

What it is

Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro, combining the ACTH(4–7) fragment with a Pro-Gly-Pro tail. The literature is predominantly from Russian research groups and can be found through PubMed.

Stability profile

The N-terminal methionine is the most vulnerable residue. Histidine, next to it, is also susceptible to oxidation, particularly when trace metals or light are present. There are no Asn or Gln residues, so deamidation is not a concern.

Storage

Form Recommended Notes
Sealed powder −20 °C Desiccant; inert-gas overlay after opening
Solution, days 2–8 °C Degassed water; amber tube
Solution, longer −80 °C Single-use aliquots

Analytical notes

Expected [M+H]+ is about m/z 814.9 (average). A +16 Da companion peak indicates methionine oxidation; track it over time if solutions are stored.

References

  1. PubMed literature on Semax (Met-Glu-His-Phe-Pro-Gly-Pro), an ACTH(4–7)-Pro-Gly-Pro analogue. PubMed
  2. Li S, Schöneich C, Borchardt RT. Chemical instability of protein pharmaceuticals: mechanisms of oxidation and strategies for stabilization. Biotechnol Bioeng. 1995;48(5):490–500. DOI
  3. Stadtman ER. Oxidation of free amino acids and amino acid residues in proteins by radiolysis and by metal-catalyzed reactions. Annu Rev Biochem. 1993;62:797–821. DOI
  4. Kerwin BA, Remmele RL Jr. Protect from light: photodegradation and protein biologics. J Pharm Sci. 2007;96(6):1468–1479. DOI

This sheet covers laboratory storage and handling of research material only. It does not describe use in humans or animals, and the supplier's datasheet for your lot takes priority.