Peptide of the Week: Tesamorelin, the FDA-Approved GHRH Analog
By PeptideChat Team · September 24, 2026
Many peptides discussed in the growth-hormone space have little human data. Tesamorelin is the exception. It went through large, placebo-controlled phase 3 trials and was approved by the US Food and Drug Administration in November 2010 to reduce excess abdominal fat in people with HIV who have lipodystrophy (Grunfeld 2011).
That approval covers one specific population. This week we look at what the trials showed, what has been studied beyond that indication, and how tesamorelin compares with its better-known relatives.
What it is and how it works
Tesamorelin is a synthetic, stabilized analog of human growth hormone-releasing hormone (GHRH) that keeps the hormone's full 44-amino-acid length (Falutz 2010; Clemmons 2017). A GHRH analog acts at the pituitary gland, prompting it to release the body's own growth hormone rather than supplying growth hormone directly (Dhillon 2011).
Growth hormone, in turn, raises IGF-1 (insulin-like growth factor 1). In the trials, IGF-1 was tracked as a sign that the drug was working.
Why does this matter for fat? In people with HIV on antiretroviral therapy, fat can build up inside the abdomen around the organs. This is called visceral adipose tissue, or VAT, and it is linked to higher cardiovascular risk (Falutz 2007). Tesamorelin was developed to target it.
The pivotal trials
The first phase 3 trial
The first trial randomly assigned 412 people with HIV and abdominal fat build-up to daily subcutaneous tesamorelin (2 mg, the dose used in the trial) or placebo for 26 weeks (Falutz 2007):
- Visceral fat, measured by CT scan, fell 15.2% with tesamorelin and rose 5.0% with placebo.
- Triglycerides fell by 50 mg/dL versus a 9 mg/dL rise with placebo.
- IGF-1 rose 81.0% versus a 5.0% fall with placebo.
- There were no significant differences in glucose measures.
The second trial and the pooled analysis
A second trial of 404 patients found visceral fat fell 10.9% with tesamorelin versus 0.6% with placebo over six months (Falutz 2010). When both trials were pooled (806 patients), the treatment effect on visceral fat was -15.4% at 26 weeks. Fat just under the skin of the abdomen did not change significantly, and patients' own ratings of "belly appearance distress" improved (Falutz 2010).
What happens when it stops
The trials included extension phases. In patients who continued, the reduction in visceral fat was maintained at about 18% over 52 weeks. In those switched to placebo, visceral fat came back (Falutz 2008). The effect lasts only as long as treatment does.
What is known outside the approved use
Several studies have explored other questions. Most are small, and none extends the approval.
Liver fat in HIV. In a 50-person trial, tesamorelin reduced both visceral fat and liver fat over six months, with a net treatment effect of -2.9% in liver lipid-to-water percentage (Stanley 2014). A later 61-person, 12-month trial in people with HIV and non-alcoholic fatty liver disease found a 37% relative reduction in liver fat fraction versus placebo (Stanley 2019). Both were still in people with HIV.
Type 2 diabetes. Because growth hormone can worsen insulin resistance, one 12-week trial in 53 people with type 2 diabetes checked specifically for that. It found no significant change in insulin response or glycemic control (Clemmons 2017). The study was sponsored by the drug's manufacturer.
Cognition in older adults. A 20-week randomized controlled trial in 152 adults aged 55 to 87, some with mild cognitive impairment, reported a favorable effect on cognition overall, with the clearest effect on executive function (Baker 2012). This is a single trial and has not led to an approved use.
An early review noted that other potential uses for tesamorelin "appear less promising" than the HIV indication (Wang 2009).
Side effects reported in trials
In the phase 3 program, tesamorelin was generally well tolerated. Serious treatment-emergent adverse events occurred in fewer than 4% of patients over 26 weeks. Most adverse events were injection-site reactions or effects known from growth hormone therapy, such as joint pain (arthralgia), headache and swelling in the legs (peripheral edema) (Dhillon 2011). A 2026 meta-analysis of five randomized trials also listed muscle pain, tingling (paresthesia) and injection-site redness (Badran 2026).
A few other points from the trials:
- More patients on tesamorelin than placebo withdrew because of an adverse event in the first phase 3 trial (Falutz 2007).
- Fasting glucose rose briefly at two weeks in one trial but was not significantly different at six months (Stanley 2014).
- In older adults, adverse events (mostly mild) were reported by 68% on tesamorelin versus 36% on placebo (Baker 2012).
Reviews have pointed to limited long-term safety data as a remaining gap (Spooner 2012).
How it differs from sermorelin and CJC-1295
All three act on the same GHRH receptor, but they are built differently and have very different evidence bases.
| Tesamorelin | Sermorelin | CJC-1295 | |
|---|---|---|---|
| Structure | Stabilized full-length GHRH (1-44) | First 29 amino acids of GHRH | Modified GHRH analog built for a long half-life |
| Duration | Given daily in trials | Given daily in pediatric studies | Estimated half-life of 5.8-8.1 days |
| Main human evidence | Phase 3 trials; FDA-approved for HIV-associated abdominal fat | Diagnosis and treatment of childhood GH deficiency | Two ascending-dose trials in healthy adults |
Sermorelin is the shortest synthetic fragment of GHRH with full biological activity. It was studied mainly in children with growth hormone deficiency, where the most common side effects were facial flushing and injection-site pain (Prakash 1999).
CJC-1295 was designed to last much longer. In healthy adults, a single injection raised growth hormone 2- to 10-fold for 6 days or more, and IGF-1 1.5- to 3-fold for 9 to 11 days (Teichman 2006). For what the "DAC" label on some CJC-1295 products means, see the glossary.
For a fuller breakdown, see Sermorelin vs Tesamorelin and CJC-1295 vs Sermorelin. Tesamorelin also appears in the Tesamorelin + Ipamorelin stack; we are not aware of published trials of that combination.
The bottom line
Tesamorelin has some of the strongest human evidence of any peptide in our library, but that evidence is concentrated in one population: people with HIV and excess visceral fat. In that group, it reliably reduced visceral fat and triglycerides without clear effects on glucose, and the benefit faded after stopping. Evidence outside HIV is limited to a few small trials.
Sources
- Tesamorelin. Nat Rev Drug Discov, 2011. PMID 21283099
- Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in human immunodeficiency virus-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data. J Clin Endocrinol Metab, 2010. PMID 20554713
- Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy. Drugs, 2011. PMID 21668043
- Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med, 2007. PMID 18057338
- Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial with a safety extension. J Acquir Immune Defic Syndr, 2010. PMID 20101189
- Long-term safety and effects of tesamorelin, a growth hormone-releasing factor analogue, in HIV patients with abdominal fat accumulation. AIDS, 2008. PMID 18690162
- 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
- Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. Lancet HIV, 2019. PMID 31611038
- Safety and metabolic effects of tesamorelin, a growth hormone-releasing factor analogue, in patients with type 2 diabetes: A randomized, placebo-controlled trial. PLoS One, 2017. PMID 28617838
- 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
- Tesamorelin, a human growth hormone releasing factor analogue. Expert Opin Investig Drugs, 2009. PMID 19243281
- Body composition, hepatic fat, metabolic, and safety outcomes of Tesamorelin, a GHRH analogue, in HIV-associated lipodystrophy: A meta-analysis of randomized controlled trials. Obes Res Clin Pract, 2026. PMID 41545261
- Tesamorelin: a growth hormone-releasing factor analogue for HIV-associated lipodystrophy. Ann Pharmacother, 2012. PMID 22298602
- Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs, 1999. PMID 18031173
- Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab, 2006. PMID 16352683
This article is for educational and research purposes only and is not medical advice.