Skip to content
Peptigraph home

Tesamorelin vs MK-677: What the Research Shows

Tesamorelin and MK-677 side by side: what they are, how they are regulated and what is still unknown.

Medically reviewed by Juan Pablo Frías, MD · · DisclosureUpdated
GHRH analogFDA approved (Egrifta)TesamorelinFDA-approved GHRH analog (Egrifta) for excess abdominal fat in HIV-associated lipodystrophy; visceral fat fell 15.2% versus a 5.0% rise with placebo in a randomized trial.[10]Growth hormone+188% searches
Oral ghrelin agonist (not a peptide)Not FDA approved · research chemicalMK-677Oral growth hormone secretagogue (not a peptide); in a randomized trial in obese men it raised IGF-I about 40% versus placebo.[11]
Quick verdict

Where the research points

Summary of studies, not a recommendation

Consider Tesamorelin if…

  • you want a product with an FDA label: Egrifta is indicated to reduce excess abdominal fat in HIV-infected adults with lipodystrophy and is not indicated for weight loss management[5]
  • you want randomized data in HIV-associated lipodystrophy: Visceral adipose tissue fell 15.2% with tesamorelin and rose 5.0% with placebo by the end of treatment.[10]

Consider MK-677 if…

  • you want an oral option with randomized human data: in obese men, MK-677 25 mg daily raised serum IGF-I by about 40% versus placebo over 8 weeks (a hormone outcome)[11]
  • you are weighing trade-offs: in that trial an oral glucose tolerance test showed impairment of glucose homeostasis at 2 and 8 weeks[11]
  • you want to see a negative human trial: in Alzheimer disease, MK-677 raised serum IGF-1 but was ineffective at slowing disease progression[12]

What they have in common

  • WADA prohibits GHRH and its analogues at all times; its list names CJC-1295, sermorelin and tesamorelin[2]
  • WADA prohibits growth hormone secretagogues at all times; its list names ibutamoren (MK-677) and ipamorelin[2]
Tesamorelin is prohibited in tested sport (WADA). Status labels come from public FDA and WADA records; see the sources below.
Side by side

Spec comparison

Showing 10 of 11 fields where the two differ. PCAC vote, Jul 2026 are the same or both unknown.

FieldTesamorelinMK-677
ClassGHRH analogOral ghrelin agonist (not a peptide)
Also calledtesa, Egriftaibutamoren
FDA statusFDA approved (Egrifta)Not FDA approved · research chemical
WADAProhibited by WADA (S2.2.4)Tesamorelin is named as a GHRH analogue in S2.2.4 (growth hormone releasing factors), prohibited at all times. Tesamorelin is also an FDA-approved medicine; an athlete would need a therapeutic use exemption.No WADA record in our data
Anti-doping detection
  • A urine assay detects CJC-1295 and other GHRH analogues at very low concentrations.PMID 35298973
  • Labs expect GHRH analogues like CJC-1295 to be hard to find because of tiny urine concentrations; the study reports no detections in routine anti-doping samples.PMID 34665524
None reportedanti-doping literature, as of 2 Oct 2026
Half-life11 minutessubcutaneous (EGRIFTA WR 1.28 mg) · FDA label (Egrifta WR)[half-life by route]
Evidence strengthHuman RCT evidence, 4 of 4Strongest: eNeurologicalSci 2026, PMID 42382101[evidence grade]
Human studies we summarised11 human (11 randomized or controlled) of 12 summarised[n]
Typical study doses[dose range]
Named in FDA warning letters, 2026Yes (24 Aug 2026)Not in the letters we track

Bracketed values are pending a sourced figure. Legal data reflects the regulatory events in our tracker.

Sources

  1. 1FDA warning letters to five research-peptide sellersFDA warning letter (NuScience Peptides; 1 of 5) · 2026fda.govAccessed 2 Oct 2026
  2. 2World Anti-Doping Code International Standard Prohibited List 2026World Anti-Doping Agency · 2026wada-ama.orgAccessed 2 Oct 2026
  3. 3An antibody-free, ultrafiltration-based assay for the detection of growth hormone-releasing hormones in urine at low pg/mL concentrations using nanoLC-HRMS/MS.Journal of pharmaceutical and biomedical analysis · 2022PMID 35298973Accessed 2 Oct 2026
  4. 4Advances in the detection of growth hormone releasing hormone synthetic analogs.Drug testing and analysis · 2021PMID 34665524Accessed 2 Oct 2026
  5. 5EGRIFTA WR (TESAMORELIN) KIT [THERATECHNOLOGIES INC.]FDA label (Egrifta WR), DailyMed · current labeldailymed.nlm.nih.govAccessed 2 Oct 2026
  6. 6The effect of growth hormone-releasing hormone on cognition and brain connectivity in adults with cognition ranging from normal to mild cognitive impairment.eNeurologicalSci · 2026PMID 42382101Accessed 2 Oct 2026
  7. 7Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial.The lancet. HIV · 2019PMID 31611038Accessed 2 Oct 2026
  8. 8The Growth Hormone Releasing Hormone Analogue, Tesamorelin, Decreases Muscle Fat and Increases Muscle Area in Adults with HIV.The Journal of frailty & aging · 2019PMID 31237318Accessed 2 Oct 2026
  9. 9PubMed search: (ibutamoren[tiab] OR "MK-677"[tiab] OR MK0677[tiab]) AND (tesamorelin[tiab] OR Egrifta[tiab] OR TH9507[tiab] OR "TH-9507"[tiab])PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  10. 10Metabolic effects of a growth hormone-releasing factor in patients with HIV.The New England journal of medicine · 2007PMID 18057338Accessed 2 Oct 2026
  11. 11Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure.The Journal of clinical endocrinology and metabolism · 1998PMID 9467542Accessed 2 Oct 2026
  12. 12Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial.Neurology · 2008PMID 19015485Accessed 2 Oct 2026

Found an error? Report a correction.