What is tesamorelin?
Tesamorelin is a synthetic 44-amino-acid analog of human growth hormone-releasing hormone (GHRH), the hypothalamic peptide that signals the pituitary to release growth hormone. It keeps the full human GHRH(1-44) sequence with a C-terminal amide and adds a trans-3-hexenoyl group to the N-terminal tyrosine. In preclinical work that change made the peptide resistant to dipeptidyl aminopeptidase-IV and slowed its breakdown in rat, dog and human plasma (Ferdinandi et al., 2007). It was developed under the code TH9507.
A pharmaceutical tesamorelin product, Egrifta, was approved by the US FDA in November 2010 for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy (Grunfeld et al., 2011). The tesamorelin Disguised Alpha sells is a research-grade lyophilized peptide for laboratory use. It is not that drug product, it is not intended for that indication or any clinical use, and it is not for use in people.
Tesamorelin reference data
| Property | Value |
|---|---|
| Name | Tesamorelin |
| Aliases | TH9507, (3E)-hex-3-enoylsomatoliberin (PubChem CID 16137828) |
| Sequence | YADAIFTNSYRKVLGQLSARKLLQDIMSRQQGESNQERGARARL (44 residues, PubChem CID 16137828), with a trans-3-hexenoyl group on Tyr1 and a C-terminal amide |
| Peptide class | Stabilized GHRH analog |
| Molecular formula | C₂₂₁H₃₆₆N₇₂O₆₇S |
| Molecular weight | 5135.86 g/mol |
| CAS number | 218949-48-5 |
| Form | Lyophilized powder |
| Sizes carried | 5MG, 10MG |
| Testing | Third-party tested, with the certificate for each lot published on the product page and in the COA portal |
Formula, molecular weight, CAS number and sizes are from the tesamorelin product page; sequence and aliases are from PubChem (CID 16137828, which lists 5136 g/mol). Confirm identity and measured content against your lot's certificate.
What the research covers
Published work on tesamorelin falls into six areas. Each summary below states the model used. Human studies used the pharmaceutical product in clinical settings and describe that product, not the research material sold here.
Design and preclinical pharmacology
Non-clinical studies compared TH9507 with native hGRF(1-44)-NH2. The hexenoyl group resisted dipeptidyl aminopeptidase-IV and slowed in vitro degradation in plasma. Daily repeat studies raised plasma growth hormone and IGF-1 in pigs, rats and dogs, and the apparent elimination half-life in dogs ranged from 21 to 45 minutes. In studies of up to four months, the more pronounced reversible findings in dogs were attributed to sustained supraphysiological growth hormone and IGF-1 (Ferdinandi et al., 2007).
Growth hormone secretion physiology
In 13 healthy men studied over two weeks, tesamorelin increased mean overnight growth hormone, growth hormone pulse area and basal secretion, and raised IGF-1, while insulin-stimulated glucose uptake measured by clamp did not change significantly (Stanley et al., 2011).
Visceral adipose tissue in clinical trials
Two Phase 3, placebo-controlled trials enrolled adults with HIV and excess abdominal fat and measured visceral adipose tissue by CT. The first (412 participants, 26 weeks) reported a 15.2% decrease with tesamorelin against a 5.0% increase with placebo (Falutz et al., 2007). A pooled analysis of both trials (806 participants) reported a placebo-adjusted reduction of about 15% at 26 weeks, maintained at 52 weeks in participants who continued (Falutz et al., 2010). A later review noted that visceral fat reaccumulated after discontinuation (Dhillon, 2011).
Liver fat
A 6-month randomized trial in 50 adults with HIV and abdominal fat accumulation reported reductions in visceral fat and modest reductions in liver fat, with a transient rise in fasting glucose at 2 weeks (Stanley et al., 2014). A 12-month multicentre trial in 61 people with HIV and non-alcoholic fatty liver disease reported an absolute reduction in hepatic fat fraction of 4.1 percentage points versus placebo (Stanley et al., 2019).
Cognition in older adults
A 20-week randomized, double-blind, placebo-controlled trial enrolled 152 adults aged 55 to 87, 66 of them with mild cognitive impairment. Investigators reported a significant effect on a composite cognitive score, driven mainly by executive-function tests, along with higher IGF-1 and lower percent body fat. Mild adverse events were reported by 68% of the active group and 36% of the placebo group (Baker et al., 2012).
Analytical detection and metabolism
GHRH and its synthetic analogs are on the World Anti-Doping Agency prohibited list, so doping-control laboratories have published detection methods. One study incubated sermorelin, tesamorelin, CJC-1295 and CJC-1295 with drug affinity complex in vitro, identified and synthesized 19 major metabolites as reference materials, and built an LC-MS/MS method with detection limits generally at or below 1 ng/mL in urine (Memdouh et al., 2021). Immunoaffinity purification with high-resolution mass spectrometry has also detected tesamorelin in plasma, with a lower limit of detection under 50 pg/mL (Knoop et al., 2016).
Key studies
- Ferdinandi ES, et al. "Non-clinical pharmacology and safety evaluation of TH9507, a human growth hormone-releasing factor analogue." Basic Clin Pharmacol Toxicol. 2007. PMID 17214611. DOI 10.1111/j.1742-7843.2007.00008.x. Non-clinical pharmacology: DPP-IV resistance, plasma stability, toxicology in rats and dogs.
- Falutz J, et al. "Metabolic effects of a growth hormone-releasing factor in patients with HIV." N Engl J Med. 2007. PMID 18057338. DOI 10.1056/NEJMoa072375. Phase 3 randomized trial, 412 adults with HIV: visceral fat by CT over 26 weeks.
- Stanley TL, et al. "Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men." J Clin Endocrinol Metab. 2011. PMID 20943777. DOI 10.1210/jc.2010-1587. 13 healthy men: overnight growth hormone pulsatility, IGF-1 and insulin sensitivity.
- Grunfeld C, et al. "Tesamorelin." Nat Rev Drug Discov. 2011. PMID 21283099. DOI 10.1038/nrd3362. Drug-approval summary noting FDA approval in November 2010.
- Baker LD, 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. PMID 22869065. DOI 10.1001/archneurol.2012.1970. Randomized trial in 152 older adults with or without mild cognitive impairment.
- Stanley TL, et al. "Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial." JAMA. 2014. PMID 25038357. DOI 10.1001/jama.2014.8334. Randomized trial in 50 adults with HIV: visceral and liver fat over 6 months.
- Stanley TL, et al. "Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial." Lancet HIV. 2019. PMID 31611038. DOI 10.1016/S2352-3018(19)30338-8. Randomized multicentre trial in 61 adults with HIV and NAFLD: hepatic fat fraction.
- Memdouh S, et al. "Advances in the detection of growth hormone releasing hormone synthetic analogs." Drug Test Anal. 2021. PMID 34665524. DOI 10.1002/dta.3183. In vitro metabolism of four GHRH analogs and an LC-MS/MS urine method.
Handling and storage of lyophilized tesamorelin
General laboratory practice for this material:
- Store the lyophilized powder at -20°C, protected from light, until use (storage guidance on the product page).
- Let the sealed vial reach room temperature before opening so moisture does not condense on the powder.
- Tesamorelin can turn cloudy or gel in near-neutral, unbuffered diluents and at high concentration. Add solvent gently down the vial wall and swirl rather than shake.
- The sequence carries a methionine at position 27, and methionine side chains oxidize readily, so limit exposure to air, light and oxidizers.
- After reconstitution, keep solutions at 2 to 8°C and protected from light, and split stock into single-use aliquots to avoid freeze/thaw cycles.
- Record the lot number and keep its certificate with your notes. For quantitative work, use the measured content on the certificate rather than the label mass.
Frequently asked questions
What is the tesamorelin peptide?
Tesamorelin is a synthetic 44-amino-acid GHRH analog (5135.86 g/mol, CAS 218949-48-5) with an N-terminal trans-3-hexenoyl group that slows its breakdown in plasma compared with native GHRH (Ferdinandi et al., 2007). Researchers use it to study growth hormone release and the IGF-1 axis.
Is tesamorelin FDA approved?
A pharmaceutical tesamorelin product received FDA approval in November 2010 for one specific HIV-related indication (Grunfeld et al., 2011). That approval covers that drug product only. Disguised Alpha's tesamorelin is research-grade material for laboratory use, not that product, and is not approved for any human use.
How does tesamorelin differ from sermorelin, CJC-1295 and ipamorelin?
Sermorelin corresponds to the first 29 residues of GHRH, GRF(1-29) (Cristea et al., 2023). CJC-1295 is a long-acting GHRH analog whose estimated half-life in healthy adults was 5.8 to 8.1 days (Teichman et al., 2006). Tesamorelin keeps all 44 GHRH residues and adds the hexenoyl group. Ipamorelin belongs to a different class: a pentapeptide growth hormone secretagogue that acts through a GHRP-like receptor rather than the GHRH receptor (Raun et al., 1998).
Why does tesamorelin sometimes gel when reconstituted?
Cloudiness or gelling is usually a solubility effect, not breakdown: peptides are least soluble near their isoelectric point, concentrated solutions favor association, and shaking promotes aggregation. Our tesamorelin gelling note covers diluent choice and gentle mixing.
How should tesamorelin powder be stored?
Store the lyophilized powder at -20°C, protected from light. After reconstitution, keep it at 2 to 8°C, protected from light, and avoid freeze/thaw cycles, as listed on the product page.
Where can researchers buy tesamorelin?
Disguised Alpha sells it for laboratory research, third-party tested with the certificate published on the product page: Tesamorelin (5MG and 10MG).
Related compounds and guides
- Tesamorelin & Ipamorelin and its research guide
- Tesamorelin gelling and clumping during reconstitution
- Sermorelin Acetate
- CJC-1295 No DAC and CJC-1295 Drug Affinity Complex
- CJC-1295 No DAC & Ipamorelin
- Ipamorelin
- COA portal: every published certificate, by lot
This product is for research use only. It has not been evaluated for safety or effectiveness in humans. Not for human consumption. All products are intended for laboratory research purposes only.