The Tesamorelin Evidence File
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Metabolic research

The Tesamorelin Evidence File

Primetime AdminOctober 14, 202620 min read

Key Takeaways

  • Tesamorelin is a synthetic analog of the full 44-amino-acid human GHRH sequence, capped with a hexenoyl group that blocks DPP-4 cleavage. The FDA approved it for one indication only, reducing excess abdominal fat in HIV-infected adults with lipodystrophy.
  • The two pivotal Phase 3 trials randomized 412 and 404 patients. Visceral fat fell 18% and 14% against placebo on the label's model, and 15.2% and 10.9% in the published papers, which use a different statistical method.
  • Widely published figures for these trials disagree with the prescribing information. One competitor reports 272 patients for the second trial when the label records 404, and another carries a publisher notice saying its claims are not independently verified.
  • Tesamorelin is not a weight-loss compound. Both labels state the effect is weight neutral, and mean weight moved less than half a kilogram in either direction across both pivotal trials.
  • Anti-tesamorelin IgG antibodies appeared in 50% of patients at 26 weeks and 47% at 52 weeks. Visceral fat and IGF-1 responses were comparable with and without antibodies, so antibody formation did not track with loss of effect.
  • The glucose signal is real and often misreported. Elevated HbA1c at or above 6.5% appeared in 5% of treated patients against 1% on placebo, with a hazard ratio of 3.3.
  • Stopping treatment reverses the effect within the studied window. Patients switched to placebo at week 26 regained 25 cm2 and 24 cm2 of visceral fat by week 52, while those who continued held their reduction.
  • The cognitive evidence does not point one way. Baker 2012 found a favorable effect in 152 older adults over 20 weeks, and the 2025 trial by Ellis and colleagues found no significant difference between groups.
  • Egrifta WR was approved on March 25, 2025 and reached market on July 15, 2025. Its 11.6 mg vial is reconstituted once a week, and the label states it is not substitutable with Egrifta SV.
  • Research-grade tesamorelin is not Egrifta. FDA warning letters dated August 24, 2026 named tesamorelin among products marketed as unapproved new drugs, and research-use labeling did not protect those sellers.

The short answer

Tesamorelin is a synthetic analog of growth hormone-releasing hormone, built from the full 44-amino-acid human GRF sequence with a hexenoyl cap on the N-terminal tyrosine. The FDA approved it for one use only, reducing excess abdominal fat in HIV-infected adults with lipodystrophy. Two pivotal trials cut visceral fat by 18% and 14% against placebo.

Last updated on 14 October 2026. Every figure, label citation and regulatory date here was checked twice. Sources were the FDA prescribing information on DailyMed, the approval letters on Drugs@FDA, and the trial record on PubMed.

Why the published tesamorelin numbers do not match each other

Two Phase 3 trials enrolled 816 HIV-positive adults with excess abdominal fat. Four widely read sources report those trials, and they report four different sets of figures.

One page gives a sample of 272 for the second trial. The approved label records 404 randomized. Another page reports a 15.2% drop in visceral fat, a third reports 18%, and both are citing the same study. A fourth page carries a notice from its own publisher warning readers that its claims are not independently verified.

None of this is hard to check. Every figure sits in the FDA prescribing information, which anyone can read. What follows grades each trial against that record, names what the evidence establishes, and says plainly where the published numbers went wrong.

What tesamorelin actually is

Your hypothalamus makes growth hormone-releasing hormone, a 44-amino-acid peptide that tells the pituitary to release growth hormone. Native GHRH does not last long. The enzyme dipeptidyl peptidase-4 cleaves it within minutes of release.

Tesamorelin keeps that whole 44-residue sequence and adds a hexenoyl group. That six-carbon chain carries a double bond at position three, bolted to the N-terminal tyrosine. That cap blocks the spot DPP-4 attacks. The prescribing information gives the free-base molecular weight as 5,135.9 daltons and the acetate salt formula as C221H366N72O67S with roughly seven acetate groups.

Theratechnologies developed the compound in Canada under the code TH9507. Building a 44-residue chain at consistent purity is not trivial, and our guide to solid-phase peptide synthesis covers how chains that long get assembled.

Three things share the name tesamorelin, and this article keeps them apart throughout. First, there is the molecule itself. There are the approved drug products Theratechnologies sells under the Egrifta names. And there is research-grade material supplied for laboratory work, which is not the approved drug and carries none of its approval.

How it works on the pituitary

Tesamorelin binds human GRF receptors with potency similar to the body's own GHRH, according to the label. Those receptors sit on somatotroph cells in the anterior pituitary. Binding triggers synthesis and pulsatile release of growth hormone, which acts on chondrocytes, osteoblasts, myocytes, hepatocytes and adipocytes.

The pulsatile part of that matters. Supplying growth hormone directly overrides the body's own control. Stimulating the pituitary leaves the feedback loop intact, so rising IGF-1 damps further release. In the pivotal trials IGF-1 climbed by roughly 107 ng/mL. The label reports no clinically significant change in thyroid-stimulating hormone, luteinizing hormone, ACTH or prolactin.

One widely repeated number deserves scrutiny. Three of the five most-read tesamorelin pages state a half-life of 26 to 38 minutes. The one page that cites a source for it cites an encyclopedia. The current prescribing information says something different. Egrifta SV reports a mean elimination half-life of 8 minutes in healthy subjects at the 1.4 mg dose. Egrifta WR reports 11 minutes at 1.28 mg. Neither current label supports the 26 to 38 minute range.

What each trial measured, and how strong the evidence is

Grades below follow one hierarchy, declared here so the labels mean something.

  1. Primary human interventional evidence
  2. Human observational evidence
  3. Animal evidence
  4. In-vitro evidence
  5. Analytical and characterization evidence
  6. Mechanistic rationale
  7. Insufficient or conflicting evidence
  • Trial: Falutz 2007, NCT00123253 — Population: HIV-positive adults, lipodystrophy, excess abdominal fat — N: 412 randomized, 273 drug and 137 placebo — Duration: 26 weeks — Primary endpoint: Percent change in visceral fat by CT at L4-L5 — Result: VAT down 15.2% against a 5.0% rise on placebo in the published paper; the label's model gives 18% against 2% — Key limitation: Single population, 80% completion, diabetic patients excluded at entry — Grade: 1. Primary human interventional
  • Trial: Falutz 2010, NCT00435136 — Population: HIV-positive adults, lipodystrophy — N: 404 randomized, 270 drug and 126 placebo — Duration: 26 weeks, then 26-week extension — Primary endpoint: Visceral fat — Result: VAT down 10.9% against 0.6% at six months in the paper; the label's model gives 14% against 2% — Key limitation: 74% completion, same narrow population — Grade: 1. Primary human interventional
  • Trial: Extension phases, NCT00123253 and NCT00435136 — Population: Completers re-randomized to drug or placebo — N: 207 and 177 — Duration: Weeks 26 to 52 — Primary endpoint: Maintenance of visceral fat reduction — Result: Continued treatment held the gain; switching to placebo gave it back — Key limitation: Only completers entered, so the healthiest patients remain — Grade: 1. Primary human interventional
  • Trial: Stanley 2014, NCT01263717 — Population: HIV-positive adults with abdominal fat accumulation — N: 50 randomized, 48 treated — Duration: 6 months — Primary endpoint: Visceral fat and liver fat — Result: VAT down 34 cm² against a 8 cm² rise; liver fat down 2.0% against a 0.9% rise — Key limitation: Small, single-centre, described by its authors as preliminary — Grade: 1. Primary human interventional, small
  • Trial: Baker 2012, NCT00257712 — Population: Adults aged 55 to 87, with and without mild cognitive impairment — N: 152 enrolled, 137 completed — Duration: 20 weeks — Primary endpoint: Executive function, verbal memory, visual memory — Result: Favorable overall cognitive effect, p=0.03; executive function p=0.005; verbal memory a trend at p=0.08 — Key limitation: Never replicated, used a 1 mg dose, adverse events in 68% against 36% — Grade: 1. Primary human interventional, unreplicated
  • Trial: Friedman 2013 substudy — Population: Subset of the Baker trial — N: 30 — Duration: 20 weeks — Primary endpoint: Brain GABA, NAAG and myo-inositol by spectroscopy — Result: GABA rose in all three regions measured — Key limitation: A 30-person substudy of one trial, mechanistic in purpose — Grade: 6. Mechanistic rationale
  • Trial: Ellis 2025, NCT02572323 — Population: HIV-positive adults, virally suppressed, abdominally obese — N: 73 randomized 3:2 — Duration: 6 months — Primary endpoint: Change in neurocognitive performance — Result: No significant difference between groups, p=0.673 — Key limitation: Open-label, no placebo arm, authors note insufficient power — Grade: 1. Primary human interventional, negative

Every row above comes from the prescribing information or from the trial record on PubMed. Nothing is carried over from a secondary summary.

Where the published figures disagree, and what the primary sources say

Each row below was checked twice. Trial figures came from the FDA prescribing information for Egrifta SV and Egrifta WR on DailyMed, and from the trial papers on PubMed. Regulatory dates came from the FDA approval letters and the approval history for application 022505 on Drugs@FDA. Where a published paper and the label disagree, both appear with the method that produced each.

  • Figure: Study 1 sample — What various sources publish: 412 — What the primary source says: 412 randomized, 273 to drug and 137 to placebo — Why they differ: No conflict, only missing detail
  • Figure: Study 2 sample — What various sources publish: 272, or 404 — What the primary source says: 404 randomized, 270 to drug and 126 to placebo — Why they differ: Transcription error in one source
  • Figure: Study 1 visceral fat change — What various sources publish: 15.2%, 17.8%, or 18% — What the primary source says: The paper reports 15.2% against a 5.0% placebo rise. The label's log-transformed model reports 18% against 2% — Why they differ: Different statistical model, both correct
  • Figure: Study 2 visceral fat change — What various sources publish: 14%, or not reported — What the primary source says: The paper reports 10.9% at six months. The label's model reports 14% against 2% — Why they differ: Different statistical model, both correct
  • Figure: Combined enrolment — What various sources publish: 816, or 800 — What the primary source says: 816, being 412 plus 404 — Why they differ: Rounding in secondary sources
  • Figure: Half-life — What various sources publish: 26 to 38 minutes — What the primary source says: 8 minutes for Egrifta SV, 11 minutes for Egrifta WR — Why they differ: Tertiary source repeated without checking the label
  • Figure: Antibody rate — What various sources publish: 49.5% at 26 weeks — What the primary source says: 50% at 26 weeks and 47% at 52 weeks — Why they differ: One timepoint reported, slightly misstated
  • Figure: Cognitive trial author and sample — What various sources publish: Baker 2012 with 137, or Friedman 2021 with 152 — What the primary source says: Both figures belong to Baker 2012. It enrolled 152 and 137 completed. No Friedman 2021 tesamorelin trial exists — Why they differ: Author misattribution, enrolled against completed
  • Figure: Egrifta SV approval date — What various sources publish: October 19, 2019 — What the primary source says: The FDA approval letter for supplements S-012 and S-013 is dated July 5, 2019 — Why they differ: Secondary sources cite a later date than the approval letter
  • Figure: Ellis 2025 primary p-value — What various sources publish: 0.673 — What the primary source says: The abstract reports 0.673 and the results section reports 0.573 — Why they differ: The paper disagrees with itself, and neither value is significant

Two of those rows need explaining, because a reader could mistake a modelling difference for an error.

The 15.2% and 18% figures describe the same trial. The published paper reports a straightforward percent change. The label derives its figure from a log-transformed model that adjusts for baseline visceral fat. Both are defensible, they answer slightly different questions, and a source that prints one without saying which it is leaves readers unable to reconcile them.

Confusion about the cognitive trial has a cleaner cause. One source attributes a 20-week trial in 137 people to Baker 2012. Another attributes a 20-week trial in 152 people to Friedman 2021. Both numbers come from the same study, Baker 2012, which enrolled 152 participants and saw 137 finish. Seth Friedman co-authored that paper and led a 30-person neurochemical substudy published in 2013. A 2021 tesamorelin cognitive trial does not exist in the literature.

What happened to liver fat, triglycerides and lean mass

Stanley and colleagues ran the liver question properly in 2014. Fifty HIV-positive adults with abdominal fat accumulation were randomized, 48 received treatment, and the trial ran six months at Massachusetts General Hospital. Liver fat fell 2.0% on the lipid-to-water measure while the placebo group rose 0.9%. Visceral fat fell 34 cm² against an 8 cm² rise. The authors called their own findings preliminary and asked for further study, which is the correct reading of a 48-person result.

Body composition in the pivotal trials moved in two directions at once. Trunk fat dropped 1.0 kg in the first study and 0.8 kg in the second. Lean body mass rose 1.3 kg and 1.2 kg over the same period. Triglycerides fell 50 mg/dL in the Falutz 2007 trial while the placebo group rose 9 mg/dL.

Total weight barely moved. Across both pivotal trials the mean weight change sat within half a kilogram in either direction. The label records a weight neutral effect. Fat left one compartment, lean tissue arrived in another, and the scale registered almost nothing.

That is the entire point of the compound, and it makes the scale a useless way to judge it.

Why the memory trials do not agree

Three studies have looked at cognition, and lumping them together produces nonsense.

Baker and colleagues published the only positive result in 2012. They enrolled 152 adults aged 55 to 87, two-thirds of them cognitively healthy and the rest with mild cognitive impairment, and 137 finished. Participants injected 1 mg daily before bed for 20 weeks. The intent-to-treat analysis showed a favorable cognitive effect at p=0.03, executive function improved at p=0.005, and verbal memory reached only a trend at p=0.08. IGF-1 rose 117%, body fat fell 7.4%, and adverse events were reported by 68% of the treated group against 36% on placebo.

Friedman led a substudy of those same participants, published in 2013. Thirty people underwent brain spectroscopy, and GABA rose across all three regions measured. A substudy of one trial measuring brain chemistry is mechanistic support, not a second positive result.

Ellis and colleagues published the most recent trial in 2025, and it did not replicate anything. Seventy-three HIV-positive adults with abdominal obesity were randomized three to two against standard of care for six months. Neurocognitive performance showed a trend in the treated group and no significant difference between groups at p=0.673. Waist circumference did fall in that trial. The authors flag insufficient power and the absence of a placebo arm.

One further limitation belongs in this section. Both labels state there is no information on use in patients over 65 years of age. Baker's trial enrolled people up to 87.

What the safety record actually shows

The glucose finding is the one most often reported wrongly. One widely read page states that no cases of diabetes developed in the trials. The label records the opposite finding. Elevated HbA1c at or above 6.5% appeared in 5% of treated patients against 1% on placebo. The hazard ratio was 3.3, with a confidence interval running from 1.4 to 9.6. Mean baseline HbA1c was 5.3% in both groups.

Adverse reactions read differently with placebo rates alongside them, which is how the label presents them. Across the combined 26-week phase, 543 patients received the drug and 263 received placebo.

  • Reaction: Injection site reactions — Drug: 17% — Placebo: 6%
  • Reaction: Arthralgia — Drug: 13% — Placebo: 11%
  • Reaction: Pain in extremity — Drug: 6% — Placebo: 5%
  • Reaction: Myalgia — Drug: 6% — Placebo: 2%
  • Reaction: Peripheral edema — Drug: 6% — Placebo: 2%
  • Reaction: Paresthesia — Drug: 5% — Placebo: 2%

The label separately reports injection site reactions at 25% against 14% across all studies over 26 weeks. Hypersensitivity reactions occurred in 4% of treated patients. Joint pain is worth noting for what it does not show. At 13% against 11%, arthralgia barely separates from placebo, and sources quoting the 13% alone imply a signal the comparison does not support.

Four contraindications apply: active malignancy, disruption of the hypothalamic-pituitary axis, known hypersensitivity, and pregnancy.

The cancer question needs care, because it gets asked constantly and answered badly. Growth hormone is a growth factor, IGF-1 rises during treatment, and the label states plainly that the effects of prolonged IGF-1 elevation are unknown. Among patients treated 26 weeks, 47% had IGF-1 more than two standard deviations above normal and 36% exceeded three. Lifetime carcinogenicity studies in rodents have not been conducted with tesamorelin acetate. Mutagenicity testing came back clean across the Ames test, mammalian cell assays and chromosomal damage in mice. What exists is a theoretical concern, a monitoring requirement and an absence of long-term data. No trial has shown tesamorelin causing cancer, and no trial has been run that could.

The antibody question almost nobody covers

Half the patients in the pivotal trials developed antibodies to the drug. Not one of the five most-read tesamorelin pages mentions it.

Anti-tesamorelin IgG antibodies appeared in 50% of patients treated for 26 weeks and 47% of those treated for 52 weeks. Within the subset who had hypersensitivity reactions, 85% were antibody positive. Roughly 60% of antibody-positive patients showed cross-reactivity to their own endogenous GHRH. In-vitro neutralizing antibodies to tesamorelin appeared in 10% of treated patients at week 52, and to human GHRH in 5%.

Here is the part that makes the number less alarming than it sounds. Patients with and without antibodies had similar mean reductions in visceral fat and similar IGF-1 responses. The same held for patients with and without neutralizing antibodies. Antibody formation did not track with loss of effect in these trials.

Antibodies also faded after treatment stopped. Among patients who were antibody positive at 26 weeks and reassessed six months after stopping, 18% remained positive.

The label adds a caveat worth repeating. Antibody incidence depends heavily on assay sensitivity and specificity, so these percentages do not transfer to other studies or other compounds.

What happens when treatment stops

Both pivotal trials answered this by design, which makes the evidence unusually clean. Patients who completed 26 weeks on drug were re-randomized to continue or switch to placebo for another 26 weeks.

Those who switched to placebo gained visceral fat back. The first study's switchers added 25 cm², and the second study's added 24 cm². Patients who stayed on treatment changed by 3 cm² and negative 11 cm² respectively. Expressed as percentages, the switchers rose 22% and 16% while the continuers moved 0% and negative 5%.

Other body-composition measures moved with it. Trunk fat rose 1.4 kg and 1.09 kg in the switching groups. Lean body mass fell 1.8 kg and 1.7 kg.

What this establishes is narrow and solid. Within a 52-week window, in this population, the effect depends on continued exposure. What it does not establish is anything about longer horizons, about people outside the trials, or about any pattern of starting and stopping. No trial has compared continuous treatment against any alternative schedule.

What the evidence does not prove

Nothing establishes an effect outside HIV-associated lipodystrophy. Every participant in both pivotal trials was HIV-positive with lipodystrophy. The argument for other populations is a mechanism argument. Mechanism arguments are reasonable and they are not trial results.

No evidence supports general weight loss either. The label calls the effect weight neutral, and the trial tables bear that out.

Long-term cardiovascular safety has never been established. The label states this as a formal limitation of use and tells prescribers to weigh continuation in patients whose visceral fat has not fallen.

Comparison against GLP-1 receptor agonists is a category error. Those drugs act on appetite and produce large total weight loss. Tesamorelin redistributes fat without moving the scale. Setting their magnitudes side by side compares two different measurements.

Safety past roughly a year is unmeasured. The pivotal trials ran 52 weeks. Ten years of pituitary stimulation in someone outside the studied population has never been observed in a trial.

How tesamorelin compares with ipamorelin, sermorelin and CJC-1295

The grouping of these compounds hides how little they share. Three of the four are a GHRH peptide of some kind, one is not, and the evidence behind each name differs by orders of magnitude.

  • Property: Class — Tesamorelin: GHRH analog — Sermorelin: GHRH analog — CJC-1295: GHRH analog — Ipamorelin: Ghrelin mimetic
  • Property: Length — Tesamorelin: 44 residues — Sermorelin: 29 residues — CJC-1295: 29-residue base — Ipamorelin: 5 residues
  • Property: Receptor — Tesamorelin: GHRH receptor — Sermorelin: GHRH receptor — CJC-1295: GHRH receptor — Ipamorelin: Ghrelin receptor, GHS-R1a
  • Property: Signalling — Tesamorelin: Gs, adenylyl cyclase, cAMP — Sermorelin: Gs, cAMP — CJC-1295: Gs, cAMP — Ipamorelin: Gq/11, phospholipase C, calcium
  • Property: Stabilization — Tesamorelin: N-terminal hexenoyl cap against DPP-4 — Sermorelin: None added — CJC-1295: Varies by form — Ipamorelin: Non-natural and D-form residues
  • Property: Regulatory status — Tesamorelin: FDA approved as Egrifta — Sermorelin: No current approval — CJC-1295: No approval — Ipamorelin: No approval
  • Property: Controlled human trials — Tesamorelin: Two Phase 3 trials plus others — Sermorelin: Limited — CJC-1295: Limited — Ipamorelin: Largely preclinical

Tesamorelin, sermorelin and CJC-1295 all act at the GHRH receptor through the same second messenger. Ipamorelin works through an entirely separate door, the ghrelin receptor, raising intracellular calcium and functionally opposing somatostatin, the signal that brakes growth hormone release. Researchers study GHRH-receptor and ghrelin-receptor agonists together because the two inputs converge on one cell from different directions.

The comparison stops at these properties. Tesamorelin has controlled human trials and an approval behind it, and the others do not. Any performance ranking between them is unsupported by the record.

Where tesamorelin stands with regulators right now

Three products have carried the tesamorelin molecule to market, and they are not interchangeable.

  • Product: Egrifta, original — Approved: November 10, 2010 — Vial strength: 1 mg per vial — Daily dose: 2 mg — Reconstitution: Daily
  • Product: Egrifta SV — Approved: July 5, 2019 — Vial strength: 2 mg per vial — Daily dose: 1.4 mg — Reconstitution: Daily, used immediately
  • Product: Egrifta WR — Approved: March 25, 2025 — Vial strength: 11.6 mg per vial — Daily dose: 1.28 mg — Reconstitution: Weekly, one vial covers seven days

Those dose figures are regulatory facts drawn from the DailyMed prescribing information, stated here for accuracy and not as guidance of any kind. The 2 mg figure that circulates widely belongs to the original formulation and to the pivotal trials. Neither currently marketed product uses it.

Egrifta WR is the development no explainer covers. The FDA approved it on March 25, 2025, the label was revised that month, and marketing began July 15, 2025 under BLA022505. Its design solves a practical problem. One vial reconstituted once covers seven consecutive daily doses, against the original requirement to mix a fresh vial daily. Both labels state the two formulations are not substitutable, citing differences in dosage, vial count, reconstitution and storage.

One of those dates is worth pinning down, because secondary sources get it wrong. Several place the Egrifta SV approval in October 2019. The FDA approval letter covering the Egrifta SV proprietary name is dated July 5, 2019.

In sport, the position is unambiguous. The WADA Prohibited List names tesamorelin by name at section S2.2.4, under growth hormone releasing factors, prohibited at all times in and out of competition. CJC-1293, CJC-1295 and sermorelin appear in the same line.

The newest regulatory development concerns sellers, not the molecule. On August 24, 2026 the FDA's Center for Drug Evaluation and Research issued warning letters to five online peptide sellers. The agency posted them publicly on September 1. Tesamorelin was named in several of those letters as an unapproved new drug under section 505(a) of the Federal Food, Drug, and Cosmetic Act. The letter to Peptide Partners LLC cited "Tesa Peptide (Tesamorelin)" alongside six other products. The letter to Peak Performance Peptides cited tesamorelin among six. NuScience Peptides was cited over a tesamorelin research peptide and a tesamorelin ipamorelin blend.

Reasoning in those letters matters more than the names. FDA reviewed what each website said about its products and found marketing describing effects on the body. Research-use labeling did not survive that reading. Our guide to US peptide law in 2026 sets out the full enforcement record and what research use only means legally.

What this means for research material

Research-grade tesamorelin is not the Egrifta product. It is not manufactured under the quality system that supports an approved biologic, and it carries no approval. All the trial evidence above concerns the pharmaceutical product in its studied population. Nothing here describes or implies any use in a person or animal.

A certificate of analysis speaks to identity and purity by a stated method on a stated lot. It establishes nothing about safety, efficacy or legal status. Our COA guide explains what each section proves and where its limits sit. Our supplier due-diligence checklist covers how to assess documentation and sourcing before ordering.

PrimeTime BioLabs supplies tesamorelin peptide as a research material with third-party HPLC and mass spectrometry testing and a lot-matched certificate. It is sold strictly for laboratory research use, and it is not for human or veterinary use.

Nothing on this page is medical advice. It summarizes published trial results and public regulatory documents for an audience doing laboratory work.

The bottom line

Tesamorelin has something most research peptides lack, which is a real evidence base. Two Phase 3 trials, an approval, a published safety profile and a measured rebound after discontinuation all sit in the public record. Visceral fat falls, lean mass holds or rises, and total weight stays where it was.

Everything established sits inside one population. Every pivotal participant was HIV-positive with lipodystrophy, and every trial ran a year or less. The cognitive question has one positive trial from 2012 and one negative trial from 2025.

Two open questions are worth watching. The cognitive picture needs a properly powered placebo-controlled trial before anyone can call it either way. Those warning letters from August 2026 also signal that FDA reads seller websites closely. How a compound gets described is now a live regulatory question.

References

  1. 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. PMID 18057338.
  2. Falutz J, Potvin D, Mamputu JC, et al. Effects of tesamorelin, a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat. J Acquir Immune Defic Syndr. 2010;53(3):311-322. PMID 20101189.
  3. Stanley TL, Feldpausch MN, Oh J, 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;312(4):380-389. PMID 25038357.
  4. 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. Arch Neurol. 2012;69(11):1420-1429. PMID 22869065.
  5. Friedman SD, Baker LD, Borson S, et al. Growth hormone-releasing hormone effects on brain gamma-aminobutyric acid levels in mild cognitive impairment and healthy aging. JAMA Neurol. 2013;70(7):883-890. PMID 23689947.
  6. Ellis RJ, Vaida F, Hu K, et al. Effects of tesamorelin on neurocognitive impairment in persons with HIV and abdominal obesity. J Infect Dis. 2025;231(5):1230-1238. PMID 39813152.
  7. EGRIFTA SV (tesamorelin) for injection, prescribing information. Theratechnologies Inc. DailyMed, US National Library of Medicine.
  8. EGRIFTA WR (tesamorelin) for injection, prescribing information. Theratechnologies Inc. DailyMed, US National Library of Medicine.
  9. World Anti-Doping Agency. The Prohibited List, section S2.2.4, growth hormone releasing factors.
  10. US Food and Drug Administration. Warning Letter, Peptide Partners LLC, MARCS-CMS 735063, August 24, 2026.
  11. US Food and Drug Administration. Warning Letter, Peak Performance Peptides, MARCS-CMS 735127, August 24, 2026.
  12. US Food and Drug Administration. Approval letter, NDA 022505, supplements S-012 and S-013, EGRIFTA and EGRIFTA SV, July 5, 2019.
  13. US Food and Drug Administration. Drugs@FDA approval history, application 022505 (tesamorelin), original approval November 10, 2010 and supplement 20 approved March 25, 2025.

Frequently Asked Questions

It comes back within the window the trials measured. Patients who completed 26 weeks on treatment and switched to placebo regained 25 cm2 of visceral fat in the first pivotal trial and 24 cm2 in the second by week 52. Those who stayed on treatment changed by 3 cm2 and negative 11 cm2. Trunk fat rose and lean body mass fell in the switching groups at the same time. No trial has examined what happens beyond 52 weeks, or in anyone outside the HIV-associated lipodystrophy population.

Antibodies develop in about half of patients, and the trial data do not show them blunting the effect. Anti-tesamorelin IgG appeared in 50% of patients at 26 weeks and 47% at 52 weeks. Patients with and without antibodies had similar mean reductions in visceral fat and similar IGF-1 responses, and the same held for the 10% who developed in-vitro neutralizing antibodies by week 52. Antibody incidence depends heavily on the assay used, so these percentages do not transfer to other studies.

No trial has shown tesamorelin causing cancer, and no trial has been designed that could answer the question. What exists is a mechanistic concern and a monitoring requirement. Growth hormone is a growth factor, IGF-1 rises during treatment, and the label states that the effects of prolonged IGF-1 elevation are unknown. Lifetime carcinogenicity studies in rodents have not been conducted. Mutagenicity testing came back clean across bacterial, mammalian-cell and in-vivo assays. Active malignancy is a contraindication.

One randomized trial has tested it directly. Stanley and colleagues published a six-month study in JAMA in 2014 with 50 patients randomized and 48 treated. Liver fat fell 2.0% on the lipid-to-water measure while the placebo group rose 0.9%, and visceral fat fell 34 cm2 against an 8 cm2 rise. The authors described their own findings as preliminary and called for further study, which is the right reading of a 48-person result. It is a genuine signal on a small sample, not an established indication.

The two trials that asked disagree, and they studied different people. Baker 2012 enrolled 152 adults aged 55 to 87, some with mild cognitive impairment, who injected 1 mg daily for 20 weeks. That trial found a favorable overall cognitive effect and a clearer effect on executive function, with verbal memory reaching only a trend. Ellis and colleagues published a 2025 trial in 73 HIV-positive adults with abdominal obesity and found no significant difference between groups. One positive unreplicated trial and one negative trial is not a settled answer.

No. Egrifta, Egrifta SV and Egrifta WR are approved drug products manufactured under the quality system that supports a licensed biologic, with an approved label and a defined indication. Research-grade material sharing the name carries none of that. Every trial result described in this article concerns the pharmaceutical product in its studied population. A certificate of analysis establishes identity and purity by a stated method on a stated lot, and it establishes nothing about safety, efficacy or legal status.

Because that is the only population the pivotal trials studied. Both Phase 3 trials enrolled HIV-infected adults with lipodystrophy and excess abdominal fat, on stable antiretroviral therapy, aged 18 to 65. Patients with type 1 or type 2 diabetes, a history of malignancy or hypopituitarism were excluded. An approval covers the population and endpoint a sponsor demonstrated. Extending it would require separate trials in a different population, and those have not been run.

Egrifta WR is the newest formulation, approved on March 25, 2025 and marketed from July 15, 2025 under BLA022505. It uses an 11.6 mg vial reconstituted once a week, where the earlier products required mixing a fresh vial every day. The labels state plainly that Egrifta WR and Egrifta SV are not substitutable, citing differences in dosage, the number of vials needed, reconstitution and storage. Its safety and efficacy rest on the original trials plus a bioavailability comparison.

The evidence is about visceral fat specifically, and the label calls the overall effect weight neutral. Across both pivotal trials, mean weight changed by less than half a kilogram in either direction. Trunk fat fell by 1.0 kg and 0.8 kg while lean body mass rose by 1.3 kg and 1.2 kg. Fat left one compartment and lean tissue arrived in another, so the scale barely registered anything. Judging this compound by total body weight misses what it was shown to do.

Yes, and this is the finding most often reported incorrectly. The label records elevated HbA1c at or above 6.5% in 5% of treated patients against 1% on placebo, with a hazard ratio of 3.3 and a confidence interval from 1.4 to 9.6. Mean baseline HbA1c was 5.3% in both groups. The limits matter: patients with diabetes were excluded from the trials, so the effect in people with existing glucose problems was never measured. Glucose evaluation before and during treatment is a labeled requirement.

Sermorelin is a GHRH analog like tesamorelin, built from a 29-residue fragment against tesamorelin's full 44. Both act at the GHRH receptor through Gs and cyclic AMP. Ipamorelin is a different kind of molecule entirely, a five-residue peptide that binds the ghrelin receptor and raises intracellular calcium through a separate pathway. The sharper difference is evidence. Tesamorelin has two Phase 3 trials and an FDA approval behind it. Neither ipamorelin nor sermorelin has a current approval or a comparable body of controlled human data.

No, and the difference is where the signal enters the system. Supplying growth hormone directly bypasses the pituitary and the feedback that normally limits it. Tesamorelin acts one step earlier, stimulating pituitary somatotrophs to synthesize and release growth hormone in pulses, which leaves the IGF-1 feedback loop intact. That said, the downstream effects still follow growth hormone biology, which is why the label carries IGF-1 monitoring requirements, fluid-retention warnings and a glucose-intolerance warning.

Very little, because nobody has measured it. The pivotal trials ran 52 weeks, and both labels state that long-term cardiovascular safety has not been established. There is no information on use in patients over 65 years of age. Lifetime carcinogenicity studies have not been conducted. The label also advises considering discontinuation in critically ill patients, based on mortality findings reported with pharmacologic growth hormone. Anyone citing a long-term safety profile for this compound is describing something the trial record does not contain.

Two separate reasons, and they need different handling. Some disagreements are genuine errors, such as a sample size of 272 published for a trial the label records as 404, or a cognitive trial attributed to a 2021 paper that does not exist. Others reflect real methodological differences. The 15.2% and 18% figures for the first pivotal trial describe the same study, because the published paper reports a plain percent change while the label derives its figure from a log-transformed model adjusted for baseline. A source that prints one number without naming the method leaves readers unable to reconcile them.

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