984 Da vs 1032 Da “Adamax”: why these are not the same compound
There has been a lot of confusion lately around vendors calling both the 984 Da compound and the 1032 Da compound “Adamax.” I want to lay out the issue chemically, because this is not just a naming preference. These are different molecular identities.
Short version
A 984 Da product may be a Semax-derived analog, but it is not the same molecule as the 1032 Da Adamax structure.
If Adamax is defined as the Semax/P021 hybrid containing the adamantyl-glycine modification, then the expected molecular weight is approximately 1032.23 g/mol.
A COA showing identity around 984 Da does not confirm that structure. It confirms a different compound.
The core problem
The name “Adamax” comes from the adamantane/adamatyl-glycine modification. That modification is not a minor cosmetic change. It is the defining structural feature of the molecule.
The 1032 Da Adamax structure is generally described as a Semax-derived peptide with:
the Semax core: MEHFPGP
an N-terminal acetyl cap
a C-terminal amide
a P021-style adamantyl-glycine modification
That adamantane cage is the whole reason the molecule is called Adamax.
So when someone says “non-adamantylated Adamax,” that should immediately raise a red flag. Removing the adamantyl group removes the defining feature of Adamax. At that point, it may be an Adamax-like analog, or a Semax-family analog, but it is not chemically the same molecule.
What the 984 Da compound appears to be
The 984 Da version commonly appears in catalogues as:
Ac-MEHFPGPAG-OH
Written out:
Ac-Met-Glu-His-Phe-Pro-Gly-Pro-Ala-Gly-OH
That is best described as an N-acetyl Semax analog extended with ordinary Ala-Gly at the C-terminus.
It is not plain Semax, because plain Semax is only the heptapeptide MEHFPGP and falls around 813–814 Da.
But it is also not the 1032 Da Adamax, because it lacks the adamantyl/P021-style modification.
So the 984 Da compound sits in the middle:
Semax: about 813–814 Da
984 compound: Ac-Semax-Ala-Gly-OH
Adamax: about 1032.23 Da, adamantylated/P021-style Semax hybrid
Those are not interchangeable.
Why mass spec settles the issue
For the 984 Da compound, expected LC-MS signals would be around:
[M+H]+ ≈ 984.4 m/z
[M+2H]2+ ≈ 492.7 m/z
For the 1032 Da Adamax structure, expected LC-MS signals would be around:
[M+H]+ ≈ 1032.5 m/z
[M+2H]2+ ≈ 516.7 m/z
That difference is not tiny. It is not a rounding issue. It is not “close enough.” It is a different molecule.
If a COA shows peaks around 984 and 492.7, that is consistent with the 984 Da Ac-MEHFPGPAG-OH compound. It does not prove the 1032 Da Adamax structure.
Purity does not fix this. A compound can be 99% pure and still be the wrong compound. Purity answers the question: “Is this sample mostly one thing?” Identity answers the question: “Is that one thing the compound on the label?”
Why “two versions of Adamax” is misleading
Some vendors are now framing this as if there are simply two valid versions:
984 Da Adamax
1032 Da Adamax
That may reflect how the grey-market vendor catalogues have evolved, but it is not clean chemistry.
A vendor can say “we sell a non-adamantyl Adamax analog” if they want to be transparent. They can say “Adamax-like Semax analog.” They can say “Ac-MEHFPGPAG-OH.”
But calling the 984 Da molecule simply “Adamax” creates a scientific identity problem.
If the original or intended Adamax design is the adamantylated Semax/P021 hybrid, then removing the adamantyl group creates a different molecule. It is not the same compound with a small variation. It is a structurally different analog.
That matters because the inferred rationale for Adamax comes from two pieces:
the Semax core
the P021-style adamantyl-glycine modification
If the adamantyl-glycine modification is missing, then the product no longer represents that hybrid design.
The naming standard vendors should follow
The correct way to label these would be:
Semax
MEHFPGP
Approx. MW: 813–814 Da
984 Da analog
Ac-MEHFPGPAG-OH
Better label: Acetyl-Semax-Ala-Gly-OH, Ac-Semax-AG-OH, or non-adamantyl Semax-Ala-Gly analog
Approx. MW: 984.10 Da
Adamax
Adamantyl/P021-style Semax hybrid
Formula commonly given as C50H69N11O11S
Approx. MW: 1032.23 Da
If a vendor wants to sell the 984 Da compound, that is their choice. The issue is not that the 984 Da molecule exists. The issue is representing it as the same Adamax that researchers expect when they see the 1032 Da adamantylated structure.
COA standard
A meaningful Adamax COA should not just say:
Identity: Adamax
It should show:
exact sequence/structure
molecular formula
theoretical molecular weight
observed LC-MS m/z peaks
whether the compound is the 984 Da non-adamantyl analog or the 1032 Da adamantylated Adamax
HPLC purity
net content
If the COA does not show the mass spectrum or expected m/z values, then “Identity: Adamax” is just a label claim, not independent proof.
Bottom line
The 984 Da compound and the 1032 Da compound are not the same molecule.
The 984 Da compound may be a Semax-family analog. It may be Adamax-like. It may be a vendor-catalogue compound that some suppliers have chosen to call Adamax.
But scientifically, if Adamax is the adamantylated Semax/P021 hybrid, then Adamax should confirm at approximately 1032.23 g/mol.
A 984 Da COA does not confirm 1032 Da Adamax.
Vendor names are marketing. Molecular weight is chemistry.