Tesamorelin and sermorelin are both GHRH analogues — they work the same upstream lever, telling the pituitary to release its own growth hormone. The difference is durability and focus: sermorelin is the short, physiologic GHRH 1-29 fragment, while tesamorelin is a stabilised, more potent molecule with dedicated visceral-fat research behind it. Both are supplied by New-U for laboratory research only — not for human use.
Sermorelin is the first 29 amino acids of GHRH — enough to activate the receptor, but it clears in minutes. Tesamorelin is a full-length GHRH(1-44) analogue with a trans-3-hexenoyl group that shields it from enzymatic breakdown, giving a stronger, longer GHRH signal. Both preserve the pituitary's somatostatin feedback, so GH stays within physiologic bounds.
| Sermorelin | Tesamorelin | |
|---|---|---|
| Class | GHRH 1-29 fragment | Stabilised GHRH(1-44) analogue |
| Receptor | GHRH receptor | GHRH receptor |
| Stability / potency | Short half-life, lower potency | Protease-resistant, more potent & sustained |
| Signature research area | Natural GH-pulse restoration, sleep, recovery | Visceral adipose tissue reduction; IGF-1 |
| Regulatory status | Formerly approved (Geref); now research compound | FDA-approved as Egrifta (HIV lipodystrophy) |
| Feedback preserved? | Yes | Yes |
| Typical framing | Gentle, physiologic GHRH probe | Stronger, targeted GHRH probe |
The clearest reason to pick one over the other in research is the visceral-fat literature: tesamorelin is the GHRH analogue with dedicated data (and an FDA approval as Egrifta) for reducing visceral adipose tissue. Sermorelin raises GH more broadly but doesn't carry that targeted body-composition evidence. If the study endpoint is visceral fat or IGF-1 magnitude, tesamorelin is the molecule with the track record; if it's modelling a natural, gentle GH rhythm, sermorelin is the lighter-touch tool.
Because both hit the same GHRH receptor, combining them is redundant. The productive pairing is a GHRH analogue plus a ghrelin-receptor agonist — see Ipamorelin vs Sermorelin for why two different receptors give supra-additive GH release.
What is the difference between tesamorelin and sermorelin?
Both are GHRH-receptor analogues. Sermorelin is the short GHRH 1-29 fragment with a brief half-life; tesamorelin is a stabilised full-length GHRH(1-44) analogue that resists breakdown, is more potent, and is the one studied (and approved as Egrifta) for visceral-fat reduction. Both research use only.
Is tesamorelin stronger than sermorelin?
In research terms generally yes — its stabilising modification gives a more sustained GHRH signal and larger IGF-1/GH effects. Sermorelin's edge is closely mimicking the body's own physiologic pulse.
Which is better for fat-loss research?
Tesamorelin has the dedicated visceral-fat data and approval; sermorelin raises GH more broadly without that targeted evidence. Research context only — not a weight-loss or human-use recommendation.
Can tesamorelin and sermorelin be combined?
They share the GHRH receptor, so combining them is redundant. Researchers instead pair a GHRH analogue with a ghrelin-receptor agonist like ipamorelin to engage two pathways. Research model only.
New-U supplies both as sealed 10-vial packs of lyophilised reference peptide, independently HPLC-verified at >99% purity by Janoshik and Freedom Diagnostics, with a per-batch Certificate of Analysis. Research use only — not for human consumption.
View Tesamorelin