Tesamorelin

Tesamorelin is a GHRH analogue that has been studied in a range of nonclinical experimental models. The following summaries reflect findings from the cited literature and should not be extrapolated to this vendor's specific product lot.

Tesamorelin 20 mg for Research Use

Certified-PEP supplies tesamorelin as a lyophilized powder (acetate salt) in a 5 mL vial, 20 mg per vial. Tesamorelin is a 44-amino-acid synthetic analog of growth hormone releasing hormone (GHRH) with a trans-3-hexenoyl group added to the N-terminus. Its formula is C221H366N72O67S and its molecular weight is 5135.9 g/mol. For larger studies, Tesamorelin 20 MG comes in a bigger vial, and the Tesamorelin/Ipamorelin Blend 13MG pairs it with a ghrelin-receptor peptide.

The compound was developed in the late 1990s by Theratechnologies in Montreal under the code TH9507. The FDA approved it on November 10, 2010 as Egrifta, specifically for HIV-associated lipodystrophy. This research product is not Egrifta and is not for use in people.

How Tesamorelin Mimics Natural GHRH to Raise Growth Hormone

Natural GHRH is a peptide made in the hypothalamus, a region of the brain. It signals the pituitary to produce and release growth hormone (GH, or hGH in humans), a protein that drives IGF-1 production in the liver. In people, GH comes out in pulses. The largest pulse usually follows sleep onset at night, and output is lower during the wake period. Tesamorelin binds the same pituitary receptor as natural GHRH, so it adds to this pulsatile pattern instead of supplying GH directly. That mechanism, leading to higher IGF-1, is why the compound shows up in fat metabolism research. In the main 26-week trial, IGF-1 rose about 81% with tesamorelin and fell 5% with placebo [4].

GHRH analogs differ in length, stability and potency. Sermorelin is the first 29 amino acids of GHRH. Tesamorelin keeps all 44 and adds the hexenoyl group. CJC No DAC is a modified 29-amino-acid version. Researchers compare them in GH release studies, often alongside ghrelin-receptor peptides such as Ipamorelin.

Half Life and Stability

The enzyme DPP-IV can break native GHRH down within minutes. A 2007 study characterized how tesamorelin resists it: the hexenoyl group slowed this breakdown in rat, dog and human plasma compared with native GHRH(1-44), and the analog stayed in circulation longer [1]. Even so, its half life is short. Published estimates run from about 8 to 38 minutes depending on formulation and study population [7].

In repeat-dose studies in rats and dogs, plasma GH and IGF-1 rose. Dogs held at sustained high GH and IGF-1 levels showed liver and kidney tissue changes, anemia and shifts in blood chemistry, and these findings reversed after dosing stopped [1].

Clinical Data: Visceral Fat and Lipid Profiles in HIV Lipodystrophy

HIV-associated lipodystrophy shifts body fat. Fat can be lost from the face, limbs and hip area while visceral fat builds up behind the abdominal wall and around the organs. In a trial published in the New England Journal of Medicine, 412 patients received daily subcutaneous injections of tesamorelin or placebo for 26 weeks. Visceral fat fell 15.2% with tesamorelin and rose 5.0% with placebo [4]. A second phase 3 trial reported an 18% reduction at week 26 [7]. Patients switched to placebo for the extension phase regained visceral fat, with increases of 16% to 22% [7].

Lipid profiles moved too. Triglycerides fell by 50 mg/dL with tesamorelin and rose 9 mg/dL with placebo, and the total cholesterol to HDL ratio improved [4]. Fasting glucose and insulin did not differ from placebo with statistical significance in that trial [4], but the label still warns about glucose intolerance and changes in insulin sensitivity [7]. In a 12-month trial in people with HIV and fatty liver disease, liver fat dropped and fewer participants showed fibrosis progression (10% vs 37% on placebo) [5]. A 20-week trial in older adults reported better scores on executive function tests [6]. Egrifta is not approved for general weight or fat loss.

In rats on antiretroviral therapy and calorie-dense diets, tesamorelin-treated groups showed significant differences from tesamorelin-free groups in glucose tolerance, lipid levels, liver triglycerides and adiposity [2]. In a related study, myocardial fibrosis appeared in the tesamorelin-free groups but not in the tesamorelin groups [3].

Reported Side Effects, Including Injection Sites

The prescribing data list joint pain, fluid retention (peripheral edema), muscle pain and pain in the limbs among common adverse reactions [7]. Reactions at injection sites, such as redness, itching and swelling, occurred in 25% of treated patients vs 14% on placebo. Trial injections were given into the abdomen. Hypersensitivity reactions, including hives and rash, were also reported. About 50% of patients developed anti-tesamorelin antibodies by week 26. The drug is contraindicated in active malignancy and pregnancy, IGF-1 is monitored during treatment, and its long-term safety profile, including the effects of sustained high IGF-1, has not been established [7]. Clinicians managing patients work from that label. None of it describes this research product.

Quality Testing and Storage

Every lot is manufactured in the USA and goes to a third-party lab for quality testing. HPLC analysis is used to identify the compound and measure purity, and lots are screened for endotoxins, heavy metals and sterility. Match the batch code on your vials to the matching report in our COA Library, and see Lab Testing for how each lot is checked. Some vendors post a generic COA, so check for a lot-matched one in any comparison.

To maintain stability, keep vials sealed, protected from light and moisture, and stored cold. Labs typically reconstitute with bacteriostatic water and log the date and time each vial is opened.

Research Use Only

Questions about dose, injection timing, administration around a last meal or before bed come up often in the online community. This page does not answer them. Tesamorelin from Certified-PEP is for laboratory research only. It is not a drug, food or supplement, it is not for human or veterinary use, and no protocol, benefits or availability claims made for Egrifta apply to it. The evidence above comes from published journal data on the approved drug and from animal studies. Read Research Purposes Only? and our FAQ, or browse all research peptides.

References

1. Ferdinandi ES, Brazeau P, High K, et al. "Non-clinical pharmacology and safety evaluation of TH9507, a human growth hormone-releasing factor analogue." Basic Clin Pharmacol Toxicol. 2007;100(1):49-58. PMID: 17214611
2. Chege BM, Mwangi PW, Githinji CG. "Dietary regimens appear to possess significant effects on the development of combined antiretroviral therapy (cART)-associated metabolic syndrome." PLOS ONE. 2024. doi:10.1371/journal.pone.0298752. PMID: 38416754
3. Chege BM et al. Electrocardiographic parameters and myocardial histopathology in Sprague Dawley rats on combined antiretroviral therapy and calorie-dense diets. 2026. PMID: 42018810
4. Falutz J, Allas S, Blot K, et al. "Metabolic effects of a growth hormone-releasing factor in patients with HIV." N Engl J Med. 2007;357(23):2359-2370. doi:10.1056/NEJMoa072375. PMID: 18057338
5. Stanley TL, Fourman LT, Feldpausch MN, et al. "Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial." Lancet HIV. 2019;6(12):e821-e830.
6. Baker LD, Barsness SM, Borson S, et al. "Effects of growth hormone-releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial." Arch Neurol. 2012;69(11):1420-1429.
7. EGRIFTA (tesamorelin for injection) prescribing information. Theratechnologies Inc. U.S. Food and Drug Administration label, NDA 022505.