# Tesamorelin + Ipamorelin: Full-Length Acyl-Capped GHRH With a Selective Secretagogue > The only GHRH-side molecule in this class with an approved reference product — how the cap works, why a 2:1 label is not 2:1 by moles, and what a blend certificate must resolve. Web page: https://peptidemedixeu.com/en/learn/what-is-tesamorelin-ipamorelin/ · Peptide Medix EU · 6 min read · Updated: 2026-03-23 Co-lyophilized at a 2:1 ratio, [this tesamorelin and ipamorelin preparation](https://peptidemedixeu.com/en/products/tesamorelin-ipamorelin/) combines a stabilised full-length GHRH analogue with a selective pentapeptide agonist at the ghrelin receptor. The GHRH side is what separates it from other growth hormone blends: tesamorelin is a 44-residue analogue of the complete human GHRH sequence bearing an N-terminal trans-3-hexenoyl group, and no other GHRH-side molecule in this class has both an approved prescription reference product and a published Phase 3 evidence base — the latter in reduction of visceral adipose tissue in HIV-associated lipodystrophy. That approval attaches to the prescription medicine rather than to research-grade material, a distinction that carries through everything below. Our [tesamorelin and ipamorelin blend](https://peptidemedixeu.com/en/products/tesamorelin/) is a co-lyophilized powder in 15 mg (10 mg/5 mg) and 30 mg (20 mg/10 mg) vials, within the growth hormone blends range. ## Where each component comes from Unlike sermorelin and the CJC-1295 family, which use the 29-residue active fragment, tesamorelin reproduces the whole 44-residue human growth hormone releasing hormone sequence. Its one modification is chemical rather than sequence-level: a trans-3-hexenoyl group fixed to the N-terminus. This acyl cap shields the peptide's weakest point, the Tyr1-Ala2 bond that dipeptidyl peptidase-4 cleaves, without replacing any residue, leaving the molecule sequence-identical to native GHRH from one end to the other. Our tesamorelin explainer sets out the chemistry, and tesamorelin vs sermorelin covers the trade-offs against the shorter native fragment. Ipamorelin came from Novo Nordisk's secretagogue programme of the 1990s, a synthetic pentapeptide assembled around aminoisobutyric acid and D-2-naphthylalanine. Selectivity is its defining published property: preclinical and human pharmacology work described growth hormone release with none of the accompanying cortisol, ACTH and prolactin rises [typical of the GHRP-2](https://peptidemedixeu.com/en/learn/what-is-ghrp-2/), GHRP-6 and hexarelin group. The detail is in our ipamorelin explainer. ## Why the two are combined The logic of the pairing rests on two receptors on one pituitary cell working through different second-messenger systems. Being Gs-coupled, the GHRH receptor responds to agonism by raising cAMP and activating protein kinase A. Being Gq-coupled, the ghrelin receptor responds by engaging phospholipase C, generating inositol trisphosphate and raising intracellular calcium. Pharmacology studies in humans and animals that combined a GHRH-class compound with a GHRP-class one have reliably reported a larger secretory response than either produces by itself, and secretagogues acting at GHS-R1a have also been described as reducing [somatostatin restraint](https://peptidemedixeu.com/en/glossary/somatostatin/), which would let the GHRH-driven response run fuller. This particular formulation imposes two design constraints. The first: a 2:1 ratio by mass is not 2:1 by moles. Given 5,135.86 against 711.85 g/mol, ten milligrams of tesamorelin works out at about 1.95 µmol while five milligrams of ipamorelin works out at about 7.02 µmol — around 3.6 [molar parts of ipamorelin](https://peptidemedixeu.com/en/learn/peptide-molecular-weight-and-moles/) to one of tesamorelin. The second: co-lyophilizing locks that proportion, so altering it means ordering separate Tesamorelin and Ipamorelin vials. When each format is appropriate is discussed in our guide to [blends against single vials](https://peptidemedixeu.com/en/learn/peptide-blends-vs-single-vials/). ## What has been studied ### Visceral adipose tissue and the approved indication Among GHRH-side molecules in this class, tesamorelin has by far the strongest human evidence. Phase 3 trials in people with HIV-associated lipodystrophy reported CT-measured reductions in visceral adipose tissue together with changes in triglycerides and IGF-1, and the prescription product was approved on that basis. Those data concern a prescription medicine given under medical supervision; they are not evidence about research-grade material or about this blend. ### Liver fat and metabolic endpoints Investigator-led studies later examined hepatic fat fraction and associated metabolic markers in the same population, once again using the approved product. That body of work explains why tesamorelin turns up in metabolic research settings rather than solely in growth-axis ones. ### Combined GHRH and secretagogue pharmacology Supporting the pairing rationale is an older, separate literature in which humans and animals received GHRH alongside a GHRP-class secretagogue, with pituitary synergy reported. That work typically used native GHRH or sermorelin rather than tesamorelin. ### Ipamorelin selectivity work Preclinical comparisons with GHRP-6 showed that [the pentapeptide triggers](https://peptidemedixeu.com/en/products/ipamorelin/) growth hormone release without the ACTH and cortisol response attached to it, which is why it is the secretagogue found in most current blends. ### What has not been studied No controlled studies of this co-formulated product have been published, and nothing establishes a 2:1 mass ratio as optimal for any research question. The composition is a formulation convention. ## Presentations available Each presentation is co-lyophilized into one vial, so a single reconstitution produces a solution holding both peptides in the stated proportion. Shorter series suit the 15 mg (10 mg/5 mg) vial, while the 30 mg (20 mg/10 mg) vial is more economical where a long study should stay on one lot. Every lot ships with a certificate reporting purity per component at ≥99% by HPLC. Where the research question concerns the approved product instead of the research compound, the reference listing is Tesamorelin (Egrifta-type), a prescription-only biologic. ## Reconstitution and storage at the bench Reconstitute the blend as a single material. Use bacteriostatic water where repeated withdrawals are planned, and sterile water where a preservative would interfere with an assay. Run the solvent down the vial wall and swirl rather than shake — tesamorelin runs to 44 residues, and agitation only adds foam and surface denaturation without dissolving anything faster. Because this blend is not 1:1, the arithmetic has to be done per component. A 15 mg (10/5) vial reconstituted with 2 mL of diluent gives 7.5 mg/mL in total, resolving to 5 mg/mL of tesamorelin and 2.5 mg/mL of ipamorelin, so 0.1 mL — ten units on a U-100 syringe — holds 500 [micrograms of the GHRH analogue](https://peptidemedixeu.com/en/glossary/micrograms-vs-milligrams/) and 250 mcg of ipamorelin. Reading the total as a single peptide is the commonest arithmetic error with blends. The method appears in our reconstitution guide. Store lyophilized vials sealed at −20 °C, away from light and moisture, and reconstituted solution at 2–8 °C through the study window, aliquoting and freezing for longer programmes. General practice is in how to store peptides. ## Purity and reading a blend certificate What a two-component certificate must answer is what the vial contains and in what proportion. Purity belongs to each peptide separately rather than to a single combined number. Mass spectrometry should display both expected masses — 5,135.86 g/mol and 711.85 g/mol — which together form a far stronger identity check than either alone, and the wide gap between them makes the peaks easy to tell apart. The HPLC trace should present two well-separated peaks with relative areas consistent with a 2:1 mass blend; one peak only, or a mismatch with the label, warrants querying the lot before anything is used. ## Regulatory position Here tesamorelin parts company with most research peptides. In the United States an approved prescription product containing it exists for one specific indication, a prescription-only biologic dispensed through pharmacy channels under medical supervision. The research-grade blend described here is neither that product nor its equivalent, and it holds none of those approvals. Ipamorelin has no marketing authorisation in any jurisdiction. Anti-doping rules prohibit GHRH analogues and growth hormone secretagogues in sport. ## Related blends and further reading The closest alternatives retain ipamorelin and change what sits on the GHRH side: CJC-1295 (No DAC) + Ipamorelin pairs it at 1:1 with a 29-residue analogue carrying four substitutions, and Sermorelin + Ipamorelin pairs it with the unmodified native GHRH (1-29) fragment. ## Frequently asked questions ### What sets tesamorelin apart from other GHRH analogues? Two things. It reproduces all 44 residues of human GHRH instead of just the 29-residue active fragment, and the only change made to it is a trans-3-hexenoyl cap on the N-terminus that stops dipeptidyl peptidase-4 from cleaving it. Nothing is substituted, so from end to end the sequence remains identical to native GHRH. ### Does a 2:1 blend contain two moles of tesamorelin per mole of ipamorelin? Quite the reverse. With masses of 5,135.86 and 711.85 g/mol, 10 mg of tesamorelin equals about 1.95 µmol while 5 mg of ipamorelin equals about 7.02 µmol, leaving roughly 3.6 moles of the pentapeptide for every mole of the GHRH analogue. Blend labels quote mass ratios, never molar ones. ### How does the reconstitution arithmetic work for an unequal blend? Component by component. Taking a 15 mg (10/5) vial up in 2 mL yields 7.5 mg/mL overall, which breaks down into 5 mg/mL of tesamorelin and 2.5 mg/mL of ipamorelin, so 0.1 mL carries 500 mcg and 250 mcg respectively. The classic blend mistake is treating the combined mass as if it were one peptide. ### Has tesamorelin been approved? A prescription product containing tesamorelin is licensed in the United States for one specific indication and reaches patients through pharmacy channels under medical supervision. Research-grade material is a different article altogether — not equivalent, and inheriting none of those approvals. ### Why is ipamorelin the secretagogue chosen for these blends? Because it is selective. Preclinical comparisons with GHRP-6 described growth hormone release unaccompanied by the ACTH and cortisol response the older GHRP series provokes, which makes for a cleaner pharmacological partner whenever the GHRH arm is the variable being studied. ### What should the certificate show? Purity given per component rather than as one figure, mass spectrometry confirming 5,135.86 g/mol and 711.85 g/mol both, and an HPLC trace with two clearly separated peaks whose relative areas match a 2:1 mass blend. If the ratio departs from the label, query the lot. ### How does it compare with CJC-1295 + Ipamorelin? Each combines ipamorelin with something on the GHRH side, but those partners differ in length, in modification strategy and in evidence base — acyl-capped full-length GHRH(1-44) here versus a 29-residue fragment carrying four substitutions — and the mass ratios differ too, 2:1 against 1:1. ## Related products - [Ipamorelin](https://peptidemedixeu.com/en/products/ipamorelin/): from €34 - [Tesamorelin](https://peptidemedixeu.com/en/products/tesamorelin/): from €72 - [Tesamorelin + Ipamorelin](https://peptidemedixeu.com/en/products/tesamorelin-ipamorelin/): from €140 --- For laboratory research use only. This page is provided for scientific and educational information. Materials referenced here are sold strictly for in-vitro laboratory research by qualified professionals — not for human or veterinary use, and nothing on this page is medical advice.