Tesamorelin with sermorelin: two GHRH analogues on one receptor, why no study has combined them, what the GHRH-plus-GHRP research shows instead, and units.
"Sermorelin and tesamorelin" is searched as a stack more often than as a comparison, and the stack idea rests on the two being different enough to add together. They are less different than that. Both are man-made versions of growth-hormone-releasing hormone (GHRH), and both act on the same receptor in the pituitary. This page sets out what is on record about combining them, which is nothing, and what the research on combining growth-hormone peptides actually tested.
Which of the two is which, molecule by molecule, is on tesamorelin vs sermorelin. The single-compound records are on the tesamorelin and sermorelin dosage pages.
The registry, counted
A ClinicalTrials.gov search for tesamorelin AND sermorelin returned 13 records on 2026-10-09. The registry treats sermorelin as a synonym for GHRH, which is why the count is not zero: each of the 13 gives one GHRH preparation, tesamorelin (under its own name or as TH9507) or GHRH 1-44, against placebo or nothing. None gives two GHRH analogues together. PubMed held 12 records naming both; they are reviews of peptide use in sport and orthopaedics and laboratory papers on detecting GHRH analogues in athletes' urine, not studies of the pair.
One receptor, two molecules
|
Tesamorelin |
Sermorelin |
| Structure |
GHRH 1-44 with a hexenoyl group |
GHRH 1-29-NH2 |
|---|
| Molecular weight |
5,136 |
3,357.9 |
|---|
| Receptor |
GHRH receptor, pituitary |
Same receptor |
|---|
| Current label |
EGRIFTA SV 1.4 mg, EGRIFTA WR 1.28 mg, once daily |
None (GEREF discontinued) |
|---|
| Half-life |
8 min (SV) and 11 min (WR) after injection, label |
4.3 min during IV infusion (Soule 1994) |
|---|
| Evidence base |
412-person 26-week trial, HIV lipodystrophy |
Open-label year in 110 GH-deficient children |
|---|
Both are short-lived, and both deliver the same instruction to the same cells: release growth hormone. A second GHRH analogue on top of the first adds more of the same signal, not a different one. The stacking guide calls this a class collision: two compounds competing for one receptor rather than adding a mechanism.
What the combination research tested instead
The combination that has been studied in people pairs a GHRH analogue with a growth-hormone-releasing peptide (GHRP), which acts on a second receptor, the ghrelin receptor. Bowers, who developed the GHRPs, reported in 1993 that GHRP-1 given intravenously at 1 mcg/kg together with GHRH 1-44 released growth hormone synergistically in humans, more than either alone. That is the reasoning behind GHRH-plus-GHRP stacks such as sermorelin with ipamorelin and the CJC-1295 and ipamorelin blend. It is a two-receptor result, and it does not extend to two GHRH analogues, for which no human data exist.
The doses that circulate, and their scale
| Amount |
Source of the figure |
Molecules (nmol) |
| Tesamorelin 1.28 mg |
EGRIFTA WR label |
≈249 |
| Tesamorelin 1.4 mg |
EGRIFTA SV label |
≈273 |
| Tesamorelin 2 mg |
Pivotal trial (Falutz 2007) |
≈389 |
| Sermorelin 200 mcg |
Clinic and vendor pages |
≈60 |
| Sermorelin 300 mcg |
Clinic and vendor pages |
≈89 |
| Sermorelin 500 mcg |
Clinic and vendor pages |
≈149 |
Added together, the labelled tesamorelin dose and 300 mcg of sermorelin come to about 362 nmol of GHRH analogue, close to the 2 mg tesamorelin dose of the pivotal trial and above either current label. No source ties that total to a measured response.
Reconstitution and the units per draw
| Amount |
2.5 mg/mL |
5 mg/mL |
10 mg/mL |
| Tesamorelin 1.28 mg |
51.2 units |
25.6 units |
12.8 units |
| Tesamorelin 1.4 mg |
56 units |
28 units |
14 units |
| Sermorelin 200 mcg |
8 units |
4 units |
2 units |
| Sermorelin 300 mcg |
12 units |
6 units |
3 units |
| Sermorelin 500 mcg |
20 units |
10 units |
5 units |
2.5 mg/mL is a 5 mg vial with 2 mL of water; 5 mg/mL is a 5 mg vial with 1 mL or a 10 mg vial with 2 mL; 10 mg/mL is a 10 mg vial with 1 mL. The EGRIFTA SV preparation is 2 mg in 0.5 mL (4 mg/mL), at which the label's 1.4 mg is 35 units; EGRIFTA WR is 8 mg/mL, at which 1.28 mg is 16 units. Each compound is drawn from its own vial; neither tesamorelin label describes mixing it with another product. Any vial and volume are worked on the tesamorelin calculator and the sermorelin calculator.
No human study has given tesamorelin and sermorelin together, so there is no measured growth-hormone or IGF-1 response, no safety record and no dose for the pair. Tesamorelin's label carries a glucose-intolerance warning and asks for IGF-1 to be monitored; those cautions were set for tesamorelin alone. Tesamorelin's approval covers one population, adults with HIV and excess abdominal fat. The compounds are covered in Medibact's Tesamorelin guide and Sermorelin guide. Nothing on this page is an instruction; product and dose belong with a prescriber.
Sources and dates
Opened 2026-10-09: the ClinicalTrials.gov intervention search for tesamorelin AND sermorelin (13 records, interventions read for each) and the single-compound counts (tesamorelin 24, sermorelin 27); the PubMed search for the pair (12 records); Bowers 1993 (PMID 8374685, abstract); PubChem records for tesamorelin (CID 16137828) and sermorelin (CID 16132413). Carried from this site's pages, each with its read date: the EGRIFTA SV and WR labels and half-lives, GEREF's status, Soule 1994 and Thorner 1996 (tesamorelin vs sermorelin page, 2026-09-23), the Falutz 2007 trial (tesamorelin page, 2026-09-18) and the clinic sermorelin figures (sermorelin page, 2026-09-18). Units and molar arithmetic by this site. Corrections go to the contact page.
