01 / Comparison
Sermorelin vs Ipamorelin, side by side.
The two names often appear together, but the molecules share little beyond an amidated C-terminus. Sermorelin is a 29-residue chain of standard amino acids, the first 29 residues of the GHRH reference. Ipamorelin is a five-residue chain built partly from nonstandard and D-configured residues.
| Sermorelin | Ipamorelin | |
|---|---|---|
| Length | 29 residues | 5 residues |
| Sequence | YADAIFTNSYRKVLGQLSARKLLQDIMSR-NH₂ | Aib–His–D-2-Nal–D-Phe–Lys–NH₂ |
| Building blocks | Standard amino acids | Includes Aib, D-2-Nal and D-Phe |
| C-terminus | Amide | Amide |
| Formula | C149H246N44O42S | C38H49N9O5 |
| Molecular weight | 3357.9 g/mol | 711.9 g/mol |
| CAS number | 86168-78-7 | 170851-70-4 |
| PubChem CID | 16132413 | 9831659 |
- IpamorelinThe five-residue chain with nonstandard and D-configured residues.
- CJC-1295 (No DAC) + IpamorelinModified GRF (1–29): this sequence with four substitutions.
02 / Molecular architecture
A closer look at the chain.
This is a GHRH-family peptide with a 29-residue backbone, YADAIFTNSYRKVLGQLSARKLLQDIMSR, built from standard amino acids and amidated at its C-terminus. It differs from modified GRF analogs and from the much shorter ipamorelin molecule.
- 29 residues
- GHRH(1–29)
- Amidated C-terminus
- 1Tyr
- 2Ala
- 3Asp
- 4Ala
- 5Ile
- 6Phe
- 7Thr
- 8Asn
- 9Ser
- 10Tyr
- 11Arg
- 12Lys
- 13Val
- 14Leu
- 15Gly
- 16Gln
- 17Leu
- 18Ser
- 19Ala
- 20Arg
- 21Lys
- 22Leu
- 23Leu
- 24Gln
- 25Asp
- 26Ile
- 27Met
- 28Ser
- 29Arg
Reference information: [1][2][3]. Actual lot identity must be verified separately.
Reading GHRH(1–29)-NH₂.
The numbers designate the first twenty-nine residues of the GHRH reference. NH₂ specifies an amidated C-terminus. These pieces together describe a defined fragment and its ending; the shorter phrase GHRH peptide leaves both fragment boundaries and terminal chemistry less explicit.
Fragment length versus analog modification.
Sermorelin’s relationship to GHRH differs from a modified GRF reference and from tesamorelin’s longer backbone. A shared family does not tell you whether residues have been substituted, whether an attachment is present or where the chain ends. Those distinctions belong in a structural comparison.
Structure and research references: [1]
03 / Read the evidence
Research & analytical context.
The technical record identifies the first 29 residues of the GHRH reference with a C-terminal amide. Chain length and amidation are both part of that identity. A shorter name such as GHRH fragment does not specify these details.
Read the references: [1][2][3].
The distinction that matters
Sermorelin, Modified GRF (1–29) and DAC-containing CJC-1295 are different reference identities. Similar pathways do not make their sequences or experimental profiles interchangeable.
04 / From reference to record
Know the lot, too.
A publication describes its own test material. Your lot’s certificate describes what was tested on that lot. Keep the compound name, batch number and reported methods together when reviewing a result.
Identity & composition
Check sequence or chemical form, terminal modifications, counterion and—where relevant—each blend component.
Analytical results
Read purity, content, sterility and endotoxin results as separate measurements. Only call a test passed when the actual report supports it.
Handling & storage notes
Lyophilized material: Store at −20°C; protect from light and moisture.
Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.
How to store lyophilized peptides05 / Reference questions
A few details, explained.
Is sermorelin identical to Modified GRF (1–29)?
No. Equal chain length does not establish equal residue identity. A modified analog must be compared by its full sequence and modifications, not just the 1–29 designation.
How does sermorelin differ from ipamorelin?
Sermorelin is a 29-residue chain of standard amino acids with an amidated end. Ipamorelin is a five-residue chain that includes Aib, D-2-Nal and D-Phe, also amidated. They share a terminal group, not a backbone, so neither sequence describes the other.
Read alongside the references: [1]
06 / Continue reading
Go to the source.
Each source is labeled by its type. External sources are not Pioneer batch certificates.
- Cayman Chemical · Sermorelin structure and primary study referencesSupplier reference · Read source (opens a new tab)
- PubChem · Sermorelin identity record, CID 16132413Public record · Read source (opens a new tab)
- PubChem · Ipamorelin identity record, CID 9831659Public record · Read source (opens a new tab)