Head-to-head
Ipamorelin vs Tesamorelin
A field-by-field comparison of Ipamorelin and Tesamorelin drawn from the PeptideIndex database: mechanism, evidence grade, half-life, administration route, reported dosing, side effects, storage and legal status. Both are indexed as growth hormone compounds, so the useful question is how they differ within that category.
Ipamorelin vs Tesamorelin: editorial summary
Ipamorelin and tesamorelin both increase endogenous growth-hormone signalling but do so through different receptors. Ipamorelin is a selective ghrelin-receptor agonist, whereas tesamorelin is a GHRH analogue.
Key considerations
- Ipamorelin's defining feature is receptor selectivity: it acts through GHS-R1a to produce a GH pulse. Tesamorelin works through the GHRH receptor and is a longer, stabilised analogue with an established clinical indication.
- Evidence maturity is another major distinction. PeptideIndex rates tesamorelin Strong and ipamorelin Moderate.
Ipamorelin characteristics
- Ipamorelin is a pentapeptide GH secretagogue with Moderate evidence. Its profile emphasises selectivity for GH release compared with older secretagogues.
Tesamorelin characteristics
- Tesamorelin is a 44-amino-acid GHRH analogue with Strong evidence and an FDA-approved indication for HIV-associated lipodystrophy.
Ipamorelin vs Tesamorelin at a glance
| Attribute | Ipamorelin | Tesamorelin |
|---|---|---|
| Category | Growth hormone | Growth hormone |
| Evidence grade | Moderate | Strong |
| Also known as | NNC 26-0161 | Egrifta, TH9507 |
| Chain | Pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) | 44 amino acid stabilised GHRH analogue |
| Mechanism | Acts as a ghrelin receptor (GHS-R1a) agonist on the pituitary, triggering a clean GH pulse. Its selectivity avoids the appetite and cortisol effects seen with older secretagogues like GHRP-6. | A stabilised GHRH(1-44) analogue that resists enzymatic degradation, producing a sustained, physiological increase in endogenous GH and downstream IGF-1. |
| Reported benefits | Clean GH pulse without hunger spikes · Better sleep quality and recovery · Mild fat-loss and body-composition support | Clinically demonstrated visceral adipose tissue reduction (~15–18%) · Improved triglycerides in trial populations · Preliminary evidence for cognitive benefit in older adults |
| Reported side effects | Mild headache · Injection-site redness · Light-headedness shortly after dosing | Joint pain and swelling · Injection-site erythema · Insulin resistance · Peripheral oedema |
| Half-life | About 2 hours | 26–38 minutes |
| Administration | Subcutaneous injection, 1–3 times daily | Daily subcutaneous injection, abdomen |
| Dosing overview | 200–300 mcg per dose, often 100–300 mcg before bed | Approved label dose is 2 mg once daily |
| Storage | Reconstituted vials refrigerated 2–8 °C, stable ~4 weeks | Refrigerated; reconstitute immediately before use per label |
| Legal status | Not FDA-approved; compounding restrictions apply in the US. Banned in sport. | FDA-approved for a specific indication; other uses are off-label. |
Key differences between Ipamorelin and Tesamorelin
Both are growth hormone compounds
Ipamorelin and Tesamorelin are both indexed under growth hormone, so they compete for the same use case rather than complementing each other. Ipamorelin: "The most selective of the growth-hormone secretagogues, valued because it lifts GH without meaningfully raising cortisol or prolactin." Tesamorelin: "The one GH-axis peptide with full FDA approval, indicated for reducing excess visceral abdominal fat in HIV-associated lipodystrophy."
Mechanism of action
Ipamorelin: Acts as a ghrelin receptor (GHS-R1a) agonist on the pituitary, triggering a clean GH pulse. Its selectivity avoids the appetite and cortisol effects seen with older secretagogues like GHRP-6. Tesamorelin: A stabilised GHRH(1-44) analogue that resists enzymatic degradation, producing a sustained, physiological increase in endogenous GH and downstream IGF-1.
Evidence quality is not equal
Ipamorelin carries a Moderate evidence grade and Tesamorelin a Strong grade on this index. The grade describes the quality of published human data, not how well a compound works — Tesamorelin has the better-documented record of the two, and claims made about Ipamorelin rest on thinner human evidence.
Half-life and dosing frequency
Ipamorelin is listed at about 2 hours; Tesamorelin at 26–38 minutes. That difference is what drives the reported schedules: 200–300 mcg per dose, often 100–300 mcg before bed versus Approved label dose is 2 mg once daily
Route of administration
Ipamorelin is administered by subcutaneous injection, 1–3 times daily. Tesamorelin is administered by daily subcutaneous injection, abdomen.
Legal and regulatory status differs
Ipamorelin: Not FDA-approved; compounding restrictions apply in the US. Banned in sport. Tesamorelin: FDA-approved for a specific indication; other uses are off-label. This is usually the most practical difference between two compounds, because it determines whether a supply chain is labelled and regulated at all.
Handling and storage
Ipamorelin is stored reconstituted vials refrigerated 2–8 °c, stable ~4 weeks. Tesamorelin is stored refrigerated; reconstitute immediately before use per label.
What Ipamorelin and Tesamorelin have in common
- Category: both listed as Growth hormone
Each compound in brief
Ipamorelin
Growth hormone · Moderate evidence
The most selective of the growth-hormone secretagogues, valued because it lifts GH without meaningfully raising cortisol or prolactin.
Considerations: Weakest GH release of the GHRPs — usually stacked with CJC-1295 · Effects build over weeks, not days · Dose ceiling: more than ~300 mcg per pulse gives diminishing returns
Tesamorelin
Growth hormone · Strong evidence
The one GH-axis peptide with full FDA approval, indicated for reducing excess visceral abdominal fat in HIV-associated lipodystrophy.
Considerations: Visceral fat returns after discontinuation · Requires monitoring of fasting glucose and IGF-1 · Expensive relative to other GH secretagogues
Frequently asked questions
Do ipamorelin and tesamorelin work through the same receptor?
No. Ipamorelin acts through GHS-R1a, while tesamorelin acts through the GHRH receptor.
Which has the stronger evidence grade on PeptideIndex?
Tesamorelin is rated Strong; ipamorelin is rated Moderate.
Are they approved for the same uses?
No. Tesamorelin has a specific FDA-approved indication, whereas ipamorelin is not FDA-approved.
Related comparisons and reading
Every figure on this page is reproduced from the compound profiles in this database and reflects published literature and commonly reported protocols. It is educational information, not medical advice, and not a recommendation to use either compound. See the medical disclaimer.