Sermorelin vs Ipamorelin vs Tesamorelin: A Research Comparison
Sermorelin, ipamorelin, and tesamorelin are three of the most-studied growth-hormone-secretagogue research peptides — and they are constantly confused, because two of them act on one receptor family and one acts on another. This comparison sorts them into their receptor families, explains how each differs, and covers how to verify research-grade material.
The key distinction: two receptor families
GH-secretagogue research peptides act on two different receptors:
- GHRH receptor — engaged by GHRH analogs: sermorelin and tesamorelin (and CJC-1295).
- GHS receptor (ghrelin receptor) — engaged by GHS agonists: ipamorelin (and the GHRPs).
So sermorelin and tesamorelin belong together (GHRH analogs), while ipamorelin sits in the other family (GHS agonist). This is why ipamorelin is often studied alongside a GHRH analog — the two families are complementary.
Side-by-side
| | Sermorelin | Ipamorelin | Tesamorelin |
| --- | --- | --- | --- |
| Receptor family | GHRH receptor | GHS (ghrelin) receptor | GHRH receptor |
| Structure | GHRH(1–29) fragment | Synthetic pentapeptide | GHRH(1–44) + N-terminal stabilizer |
| Half-life (lab) | Short | Short | Extended |
| Studied for | Minimal GHRH analog | Selective GHS agonist | Stabilized long-acting GHRH analog |
How to think about them
- Sermorelin — the minimal GHRH analog; the shortest active GHRH fragment.
- Tesamorelin — the stabilized, longer-acting GHRH analog (full 1–44 with an N-terminal group). See what is tesamorelin →.
- Ipamorelin — the selective GHS-receptor agonist from the other family; frequently paired with a GHRH analog. See what is ipamorelin →.
All three offered here are research chemicals for laboratory use only. Not for use in humans or animals.
What researchers study in the comparison
- Receptor-family pharmacology — how GHRH-receptor and GHS-receptor engagement differ.
- Half-life characterization — short (sermorelin, ipamorelin) versus extended (tesamorelin).
- Complementary pairings — a GHRH analog with a GHS agonist in the same model.
Reconstitution and handling for research
These peptides ship as a lyophilized (freeze-dried) powder for laboratory use. Standard research handling:
- Bring to room temperature before opening so condensation does not form on the cold vial.
- Add bacteriostatic water slowly down the inside wall — never spray directly onto the lyophilized cake. Let it dissolve without shaking; a gentle swirl is enough.
- Concentration is simple arithmetic: milligrams of peptide divided by milliliters of water added equals the concentration in mg/mL. For example, 10 mg reconstituted in 2 mL of bacteriostatic water yields a 5 mg/mL research stock solution.
- Keep it sterile. Wipe the stopper with alcohol, use a fresh sterile needle to draw solvent, and work in a clean area.
For a full walk-through, see our peptide reconstitution guide →.
How research-grade material is verified
Every batch from a credible US supplier should arrive with a third-party Certificate of Analysis (COA) for that exact lot. Peptide Technologies publishes a COA on every batch and ties it to a QR code on the vial. A complete COA reports:
- Identity — mass spectrometry (ESI-MS) confirming the observed mass matches the theoretical mass of the target sequence.
- Purity — reverse-phase HPLC, reported as percent peak area at a fixed wavelength (typically 220 nm). Research-grade material is ≥99% by area.
- Net content — gravimetric confirmation the vial holds the stated mass within tolerance.
- Endotoxin — LAL assay below research-grade thresholds.
If a vendor cannot show a lot-specific COA, you cannot verify what is in the vial. Browse the full COA library →
How to source research-grade material
For laboratory research, sourcing quality comes down to a few checks:
- Lot-specific COA from an accredited, independent laboratory — not a generic marketing PDF.
- HPLC purity ≥99% by peak area, with the chromatogram shown.
- US synthesis and finishing, so the chain of custody is documented end to end.
- Cold-chain shipping for lyophilized material, so the product arrives stable.
Peptide Technologies meets each of these and shows the live competitor price on every product page. See how our pricing compares →
FAQ
What is the difference between sermorelin, ipamorelin, and tesamorelin?
Sermorelin and tesamorelin are GHRH-receptor analogs; ipamorelin is a GHS (ghrelin) receptor agonist. Tesamorelin is the longer-acting of the two GHRH analogs.
Which are in the same family?
Sermorelin and tesamorelin are both GHRH analogs. Ipamorelin belongs to the separate GHS-receptor family, which is why it is often paired with a GHRH analog.
Is tesamorelin stronger than sermorelin?
They act on the same receptor, but tesamorelin is a stabilized full-length GHRH analog with a longer half-life in laboratory systems; sermorelin is the short fragment.
How are these peptides verified?
Each is verified by HPLC for purity, mass spectrometry for identity, and an LAL endotoxin assay, reported on a lot-specific third-party COA.
Are they research chemicals?
Yes. All three are research chemicals for laboratory use only. Not for use in humans or animals.