Sermorelin vs Tesamorelin: Approval, Evidence and Lab Results

The biggest difference between sermorelin and tesamorelin is that one has a current FDA label and the other does not. Tesamorelin has been FDA-approved since 2010 and is sold as Egrifta SV and Egrifta WR for one use: reducing excess abdominal fat in HIV-infected adults with lipodystrophy. Sermorelin was FDA-approved as Geref until its manufacturer discontinued it in 2008 and FDA withdrew the applications effective June 18, 2009; DailyMed lists no sermorelin label as of September 29, 2026. Both are analogs of growth-hormone-releasing hormone (GHRH), and no trial we could find compared them directly.

At a glance

How they work differently

Both act on the pituitary gland, the way the body's own GHRH does, prompting it to release the body's own growth hormone rather than supplying growth hormone directly. The difference is in the molecule. Sermorelin is the first 29 amino acids of GHRH, which a 1999 review describes as the shortest synthetic piece with full GHRH activity (Prakash and Goa, BioDrugs, 1999). Tesamorelin keeps all 44 amino acids of the human sequence and adds a hexenoyl group to the front, which is what the label means by a growth-hormone-releasing factor analog (DailyMed, EGRIFTA SV). A trial paper calls tesamorelin a "stabilized analog" of GHRH (Baker et al., Archives of Neurology, 2012).

A 2006 commentary argues that sermorelin's effect stays under the body's own brake, somatostatin, which is why it is described as harder to overshoot than injected growth hormone (Walker, Clinical Interventions in Aging, 2006). Tesamorelin's label describes the same overall route (GH release, then higher IGF-1) and requires monitoring of IGF-1 because the effect of prolonged elevation is unknown. Tesamorelin's label also lists disruption of the hypothalamic-pituitary axis as a contraindication.

What the evidence shows

Head to head: no published trial compared sermorelin and tesamorelin. We searched PubMed for both names together and found reviews and doping-analysis papers, not a comparison, and ClinicalTrials.gov's sermorelin listings turned up none. Numbers from separate trials in different populations can't be lined up against each other, so we don't.

Sermorelin. Its best evidence sits in children with idiopathic growth hormone deficiency. The 1999 review found it useful as a diagnostic test, and reported that limited data showed increased height velocity sustained over treatment in some prepubertal children; it noted that sermorelin was not directly compared with somatropin (Prakash and Goa, 1999). FDA's 2013 notice confirms the two approved uses: evaluating whether the pituitary can secrete growth hormone, and treating growth failure from idiopathic GHD in children (Federal Register, March 4, 2013). The adult anti-aging case rests on a physician's commentary (Walker, 2006), not a trial; we found no placebo-controlled trial of sermorelin for muscle, fat loss or sleep. Full detail is in our sermorelin guide.

Tesamorelin. Its evidence is stronger and narrower. In a 26-week placebo-controlled trial of 412 people with HIV and excess abdominal fat, visceral fat on CT scans fell 15.2% with tesamorelin and rose 5.0% with placebo (Falutz et al., NEJM, 2007). A 50-person placebo-controlled trial in the same population also found reductions in liver fat over six months (Stanley et al., JAMA, 2014). The one placebo-controlled trial outside HIV that we found is a 20-week study of 152 older adults, with and without mild cognitive impairment, which reported a favorable effect on executive function and a borderline one on verbal memory (Baker et al., 2012). It is a single trial, and a newer 6-month open-label trial in 73 people with HIV and abdominal obesity, which had no placebo arm, found no significant difference in cognitive change between tesamorelin and standard care (Ellis et al., Journal of Infectious Diseases, 2025). The cognitive signal is therefore unsettled. Fat-loss and muscle claims in people without HIV have no published trial that we found. See our tesamorelin guide.

One practical point about reading these records: the label and trials for tesamorelin describe people with HIV-associated abdominal fat, screened and monitored, and the label's own limitations apply to them. Sermorelin's approved uses were a diagnostic test and pediatric growth failure. Neither record was built on healthy adults, so neither says how the compound behaves in them.

So which has stronger evidence? On the evidence, tesamorelin's is stronger because it comes with large, placebo-controlled trials and a current label. Sermorelin's evidence is older and pediatric. Neither has trial support for the general-population body-composition claims that drive most grey market interest.

Side effects and risks compared

Tesamorelin's label is the more detailed document. It warns of increased neoplasm risk (preexisting malignancy should be inactive and treated before starting), elevated IGF-1, fluid retention, glucose intolerance or diabetes, hypersensitivity reactions, and increased mortality in acute critical illness. It is contraindicated in active malignancy, pregnancy and disruption of the hypothalamic-pituitary axis. The most commonly reported adverse reactions were joint pain, injection-site redness and itching, pain in the limbs, swelling and muscle pain. The label also reports that about half of trial patients developed antibodies to tesamorelin, with similar fat reductions with or without them (DailyMed, EGRIFTA SV). It states that it is not indicated for weight loss and that long-term cardiovascular safety has not been established.

Sermorelin has no current label. The older pediatric review described it as well tolerated, with transient facial flushing and injection-site pain the most commonly reported events (Prakash and Goa, 1999). FDA determined that Geref was not withdrawn for safety or effectiveness reasons, but that is a statement about why it left the market, not a modern safety profile for adults. It also means a sermorelin vial today has no label to check against. The risks that differ most between the two are therefore about information: tesamorelin's are written down, sermorelin's mostly aren't.

What the lab tests show

These figures come from independent lab reports, mostly paid for by buyers, in the VendorVerify database as of September 30, 2026 (vendors we can't identify excluded; a vial counts as failed if it is empty, under 95% pure, more than 20% under label or more than 50% over).

Sermorelin: 11 vials from 5 vendors, 9 reports. Median purity 99.31%. Median dose came in 1.2% over label, with 9 vials within ±5%. As of September 30, 2026, all 11 were within ±10% and none had failed.

Tesamorelin: 32 vials from 12 vendors, 24 reports, November 2024 to July 2026. Median purity 99.27%; 29 vials at 99% or higher and 1 under 95%. Median dose was 5.4% over label, with 11 within ±5%; 3 were more than 20% under label and 1 more than 20% over. 4 vials (12.5%) failed.

As of September 30, 2026, the sermorelin set is about a third the size of the tesamorelin set, and with 11 vials a single vendor can swing the picture, so these numbers can't rank one compound above the other. What they do show is that sermorelin's small sample was unusually close to label, while tesamorelin's larger sample included several under-label and failed vials.

Here is who has the strongest independent lab record for sermorelin right now. A vendor needs five or more lab reports on a compound to be ranked, so with this little data the table may be short or empty:

And the same for tesamorelin, where ranked isn't automatically good, and the table flags vendors with more than 5% failed vials:

Buying smarter

Check the compound-specific record rather than a vendor's reputation elsewhere: the sermorelin results page and the tesamorelin results page show reports, failed-vial rates and how recent they are. Treat any posted COA as a starting point; how to read a peptide COA and fake peptide COAs cover what to check. To get your own vial tested, see how to get a peptide tested. If a report comes back bad, stop using that batch, tell your group, take the report to the vendor, and submit it to VendorVerify. More background is in our tesamorelin test results article.

Database figures without a date update automatically from VendorVerify's lab results; dated figures are snapshots. This isn't medical advice.