Peptide Comparisons
Tesamorelin vs. Sermorelin: Same Family, Different Standing
Both prompt the pituitary the same way. One is a full-length analogue that is still an approved medicine; the other is a fragment that was withdrawn from the market.
Peptide Library Editorial · September 20, 2026 · 2 min read
Both are GHRH analogues acting on the same pituitary receptor. The differences are structural, pharmacokinetic, and regulatory — and the regulatory one matters most.
Tesamorelin is an approved medicine with a labelled indication. Sermorelin was approved and was withdrawn from the US market.
Side by side
Tesamorelin | Sermorelin | |
|---|---|---|
Structure | Full 44-residue GHRH, stabilised | GHRH (1-29) fragment |
Half-life | Longer — engineered to resist degradation | Roughly 10–20 minutes |
Status | Approved, specific indication | Withdrawn from the US market |
Labelled dose | 2 mg daily, subcutaneous | Historic labelling only |
Evidence | Randomised trials for its indication | Older, thinner by modern standards |
Full length versus fragment
Sermorelin is the first 29 amino acids of GHRH — the shortest portion retaining full activity. Tesamorelin is the complete 44-residue sequence with a modification that resists enzymatic breakdown.
That modification is the practical difference. A stabilised full-length analogue persists longer, which is why one is dosed daily as an approved medicine while the other acts within a narrow window.
See the sermorelin guide and the tesamorelin guide for each in full.
Why the approval difference matters most
Tesamorelin has an approved indication — visceral fat reduction in HIV-associated lipodystrophy — supported by randomised trials with an imaging endpoint. That is a narrow approval, and it is a real one.
Sermorelin's withdrawal is widely attributed to commercial rather than safety reasons. That distinction is genuine and often overstated: "withdrawn for business reasons" is still not "currently approved and monitored", and material sold today sits outside any regulated channel either way.
Neither approval extends to general use. Tesamorelin's label covers one condition in one population. Applying either compound outside that is an inference by analogy, not a use the evidence covers.
Where secretagogues fit alongside
Both act on the GHRH receptor. Ipamorelin and the other GHRPs act on the ghrelin receptor instead, which is the rationale for pairing the two classes — see CJC-1295 and ipamorelin and ipamorelin vs sermorelin.
The vial math
Compound | Vial | BAC water | Concentration | 1 mg |
|---|---|---|---|---|
Tesamorelin | 5 mg | 2 mL | 2.5 mg/mL | 40 units |
Tesamorelin | 10 mg | 3 mL | 3.33 mg/mL | 30 units |
Sermorelin | 5 mg | 3 mL | 1.67 mg/mL | 60 units |
Sermorelin | 10 mg | 5 mL | 2 mg/mL | 50 units |
The peptide calculator converts any vial and target into units.
Storage
Storage is the same as any reconstituted vial: 2–8 °C, protected from light, never frozen, and bounded by the shorter of peptide stability and the 28-day limit on bacteriostatic water. The bacteriostatic water guide covers the detail.
Frequently asked questions
Which is stronger?
They act on the same receptor, so the meaningful difference is duration rather than strength. Tesamorelin persists longer because it is stabilised against degradation.
Why was sermorelin withdrawn?
Reporting attributes it to commercial factors rather than a safety finding.
Is tesamorelin approved for general use?
No. Its approval covers visceral fat reduction in HIV-associated lipodystrophy specifically.
Research and educational use only. Peptide Library is an independent research and comparison platform and does not sell peptides. Nothing here is medical advice, dosing guidance, or a recommendation to administer any substance to a person or an animal. Consult a licensed clinician for anything concerning human health.
Sources
- 1. Efficacy and Safety of Tesamorelin in People Living With HIV With Lipodystrophy: A Systematic Review — Journal of the International Association of Providers of AIDS Care (2026) Source PubMed
- 2. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? — Clinical Interventions in Aging (2006) Source PubMed
Author
Peptide Library Editorial
Editorial content from Peptide Library. Research and educational use only. Not medical advice.
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