Sermorelin vs Tesamorelin: The Discontinued GHRH Analog and the Approved One

Sermorelin and tesamorelin are both copies of growth hormone-releasing hormone (GHRH), the signal that tells the pituitary to release growth hormone. Sermorelin is the first 29 amino acids of it and was approved long ago for children, as Geref, which is now discontinued.^[1][2] Tesamorelin is the full 44-amino-acid hormone with a small chemical addition, and it is approved today as Egrifta WR for one use: reducing excess abdominal fat in adults with HIV and lipodystrophy.^[4] Tesamorelin has the far stronger evidence, but its label says it is not indicated for weight loss, and as a licensed biologic it cannot be compounded.^[4][8]

Sermorelin vs tesamorelin at a glance

What each one is

Natural GHRH has 44 amino acids. Sermorelin is the first 29 of them, the shortest synthetic piece that keeps the hormone’s full activity.^[1] Tesamorelin keeps all 44 and adds a hexenoyl group, a six-carbon chain, to the first amino acid; the label describes it as a growth hormone-releasing factor analog produced synthetically.^[4] Both act on the same pituitary receptor and both raise IGF-1, the hormone growth hormone drives.^[3][5]

The human evidence for each

Tesamorelin: two large trials in people with HIV

Tesamorelin’s approval rests on two randomized, double-blind trials of daily 2 mg injections in adults with HIV whose antiretroviral treatment had led to fat building up around the abdominal organs. In the first, 412 patients were treated for 26 weeks. Visceral fat fell by 15.2% with tesamorelin and rose by 5.0% with placebo, triglycerides fell by 50 mg/dL against a 9 mg/dL rise, and IGF-1 rose by 81%. More patients on tesamorelin than on placebo left the study because of an adverse event.^[5] The second trial randomized 404 patients with the same design.^[4]

Body weight barely moved. In the label’s tables, average weight changed by −0.4 kg and +0.5 kg in the tesamorelin groups of the two trials, and the differences from placebo were not significant. The label calls the drug “weight neutral” and says it is not indicated for weight loss management.^[4] When patients were switched to placebo after 26 weeks, their visceral fat rose again, by 16% to 22% over the next 26 weeks.^[4]

Later trials have tested tesamorelin for other problems in people with HIV. In a 12-month trial of 61 people with HIV and fatty liver disease, liver fat fell by 4.1 percentage points more with tesamorelin than with placebo, a 37% relative reduction.^[6] In 39 obese adults with low growth hormone secretion, 12 months of tesamorelin raised IGF-1 more than placebo.^[13] None of these is an approved use.

Sermorelin: children, and a few small adult studies

Sermorelin was used as a single IV test for growth hormone deficiency and, given nightly under the skin, increased growth in some prepubertal children with idiopathic growth hormone deficiency, though less than daily somatropin did.^[1] In adults, a 1997 single-blind study gave 19 people aged 55 to 71 a close analog, [Nle27]GHRH(1-29), nightly for 16 weeks after a month of placebo. Growth hormone and IGF-1 rose, body weight and blood pressure did not change, and lean body mass rose in the men only.^[3] No trial of sermorelin compares with the size of tesamorelin’s.

Tesamorelin has two trials of more than 400 people each and a current label. Sermorelin has pediatric data and studies of a few dozen adults. Neither is approved for weight loss.

Regulatory status side by side

Tesamorelin: approved, and a biologic

Egrifta was approved in 2010 under a new drug application. On March 23, 2020, a change in federal law moved certain protein products to biologics licenses, and FDA’s list of applications deemed to be biologics licenses on that date includes tesamorelin acetate, Egrifta and Egrifta SV.^[7] That has a practical effect. FDA’s guidance states that for purposes of sections 503A and 503B, “a drug does not include any biological product that is subject to licensure” under the Public Health Service Act.^[8] A pharmacy therefore has no compounding route for tesamorelin. Tesamorelin offered as a compounded or research-use-only product is not Egrifta WR.

A prescriber can still write for Egrifta WR outside its label, but the label’s limits remain: long-term cardiovascular safety has not been established, it is not indicated for weight loss, and it is contraindicated in pregnancy, in active cancer and in people whose hypothalamic-pituitary system has been disrupted by surgery, tumor, radiation or head injury.^[4]

Sermorelin: discontinued, and compounded

FDA’s database lists Geref as discontinued, with a Federal Register determination that it was not withdrawn for safety or effectiveness reasons.^[2] Sermorelin is regulated as a drug, not a biologic, and it is not on any of FDA’s three 503A nomination lists.^[10] Under section 503A, a pharmacy may compound from a bulk substance that meets an applicable USP or National Formulary monograph, or, where no monograph exists, from one that is a component of an FDA-approved drug.^[9] Sermorelin was the active ingredient of an approved drug; we found no FDA statement on sermorelin specifically, so a patient can ask the pharmacy which route it relies on.

Neither peptide is in the HHS enforcement-discretion policy of October 28, 2026, which covers six other peptides.^[11] Both are banned in sport at all times: WADA names sermorelin and tesamorelin under S2.2.4 as GHRH analogs, a peptide-hormone class separate from anabolic steroids.^[12]

Safety: what each label and study shows

• Tesamorelin has labeled warnings. The Egrifta WR label warns of a possible increased risk of cancer from raised growth hormone, says the effects of long-term IGF-1 elevation are unknown and tells prescribers to monitor IGF-1, and warns of fluid retention (swelling, joint pain, carpal tunnel syndrome), glucose intolerance and hypersensitivity reactions. In trials, HbA1c of 6.5% or more developed in 5% of patients on tesamorelin and 1% on placebo.^[4]
• Its most common side effects, each in more than 5% of patients, were joint pain, injection-site redness and itching, pain in the arms or legs, swelling of the legs, and muscle pain.^[4]
• Sermorelin has no current label. In children it was well tolerated, with brief facial flushing and injection-site pain the most common effects.^[1] There is no large adult safety record, and HHS notes that compounded drugs are not FDA-approved, so FDA does not review their safety, effectiveness or quality.^[11]
• Both raise IGF-1. The tesamorelin label’s IGF-1 and glucose warnings come from the drug’s effect on growth hormone, which sermorelin shares.^[4][3] Which labs a label calls for is covered in peptide blood work.

Can they be combined?

There is little reason to, and no study has done it. Both act on the same GHRH receptor, so combining them adds a second drug for the same signal. The pairing clinics more often offer is a GHRH-type peptide with a ghrelin-receptor peptide, covered in ipamorelin vs sermorelin. Tesamorelin cannot be compounded into any blend, because licensed biologics fall outside sections 503A and 503B.^[8] For how either compares with taking growth hormone itself, or with an oral secretagogue, see MK-677 vs HGH.

To check where any other peptide stands, use our peptide status checker.