Tesamorelin and ipamorelin are often mentioned in the same breath, in clinic menus and on vendor pages, as two ways to raise growth hormone. The records behind them could hardly be less alike. One is an approved drug with a label, two 26-week trials and an adverse-reaction table; the other has two intravenous trials in hospital patients and has never been approved. This page sets the two records side by side and says what each one can and cannot tell a reader. It does not pick a winner, and it recommends nothing. How brands appear on this site is set out on our disclosure page.
The two records side by side
| Tesamorelin | Ipamorelin | |
|---|---|---|
| What it is | 44-amino-acid GHRH analogue | Synthetic five-amino-acid peptide |
| Receptor | GHRH receptor | Ghrelin receptor (GHS-R1a) |
| US status | Approved: EGRIFTA SV and EGRIFTA WR (Theratechnologies), labels effective 2026-07-29 | Never approved |
| Approved use | Excess abdominal fat in adults with HIV and lipodystrophy; "not indicated for weight loss management" | None |
| Labelled dose | 1.4 mg once daily subcutaneously (SV); 1.28 mg (WR) | None |
| Largest trials | Two 26-week placebo-controlled trials, 816 randomised, 543 on drug (NCT00123253, NCT00435136) | 117 bowel-surgery patients, IV, up to 7 days (Beck 2014); a 320-patient follow-on has no posted results |
| What the trials showed | Visceral fat −18% and −14% vs +2% and −2% on placebo; IGF-1 +107 and +108 ng/mL | Time to first tolerated meal 25.3 vs 32.6 hours, p = 0.15 |
| Half-life | About 8 and 11 minutes in the labels | About 2 hours after 15-minute infusions (Gobburu 1999) |
| Antibodies | Anti-drug antibodies in 50% at 26 weeks, 85% of those with hypersensitivity; ~60% cross-react with the body's own GHRH | Not measured in any published trial; FDA cites immunogenicity risk for compounded ipamorelin |
| Registered studies (ClinicalTrials.gov, intervention search, 2026-09-24) | 24 | 2 treatment trials, both Helsinn, both IV |
| FDA adverse-event reports (2026-09-24) | 1,588 | 11 |
| WADA 2026 | Prohibited at all times | Prohibited at all times |
Label figures are from the EGRIFTA SV prescribing information on openFDA (set ID 3d783378-b02d-4f19-99dd-0fc91a042224, effective 2026-07-29). The doses and reconstitution volumes for both EGRIFTA products are on our tesamorelin dosage page.
Two doors into the same room
Both compounds end at the same place — the pituitary releasing growth hormone, which raises IGF-1 — but they get there differently. Tesamorelin mimics the hypothalamic hormone that tells the pituitary to release growth hormone. Ipamorelin mimics ghrelin at a separate receptor, and in its founding pharmacology paper stood out among the ghrelin-receptor agonists: in pigs it released growth hormone without the rise in ACTH and cortisol that GHRP-6 and GHRP-2 produced, even at more than 200 times the effective dose (Raun et al. 1998). That selectivity is an animal finding; no trial has compared it with tesamorelin in the same people.
The half-lives look backwards at first. Tesamorelin, the approved daily drug, has a label half-life of 8 to 11 minutes; ipamorelin's measured terminal half-life is about 2 hours. A short half-life does not mean a short effect: the growth-hormone and IGF-1 response outlasts the molecule, which is why a once-daily label works. Both figures, and the rest of the class, are on our peptide half-life chart.
What each record says about side effects
Tesamorelin has an adverse-reaction table because it went through approval. In the 26-week phase, reactions reported in at least 1% and more often than on placebo included:
| Reaction | Placebo (n = 263) | Tesamorelin (n = 543) |
|---|---|---|
| Injection-site reaction | 6% | 17% |
| Arthralgia (joint pain) | 11% | 13% |
| Pain in extremity | 5% | 6% |
| Myalgia | 2% | 6% |
| Peripheral oedema | 2% | 6% |
| Paraesthesia | 2% | 5% |
| Rash | 2% | 4% |
The label adds warnings a table cannot show: people on tesamorelin were more likely to develop diabetes (HbA1c at or above 6.5%) — 5% against 1%, hazard ratio 3.3 — and the label says to evaluate glucose before and during treatment; fluid retention including carpal tunnel syndrome; hypersensitivity reactions; and "the effects of prolonged elevations in IGF-1 levels are unknown". It is contraindicated in active malignancy and pregnancy. Half of treated patients made antibodies to the drug.
Ipamorelin has no label and no table of that kind. In the surgical trial, adverse events were recorded in 87.5% of people on ipamorelin and 94.8% on placebo — which says ipamorelin did not add events to the aftermath of bowel surgery over a week, not that it is free of them in healthy people injecting it daily for months. FDA placed compounded ipamorelin in category 2 for 503B, noting it "may pose risk for immunogenicity" through aggregation or impurities. FDA's adverse-event database holds 11 reports naming it; the most frequent term is "recalled product administered". The CJC-1295 side of ipamorelin's usual pairing, which does have trial adverse-event tables, is on our CJC-1295 side effects page.
The difference in report counts — 1,588 against 11 — is a difference in reporting, not a measured difference in safety. Tesamorelin has a manufacturer obliged to forward reports to FDA; ipamorelin, sold as a research chemical or compounded, has no one in that position.
Why the comparison is lopsided
A reader asking "tesamorelin or ipamorelin" is usually comparing two vials from the same clinic menu. The record compares an approved drug in a specific population — adults with HIV and abdominal fat, most of them men, around 48 years old — with an unapproved peptide studied in healthy men by infusion and in surgical patients. Neither record describes the typical buyer, and neither measures what most buyers want: body composition, strength or recovery in healthy adults. Ipamorelin's other common comparison, with the GHRH fragment sermorelin, is on our ipamorelin vs sermorelin page, and the blend doses clinics state for it are on our CJC-1295 and ipamorelin dosage page.
What the record does not contain
A head-to-head trial; any trial of the two together; any subcutaneous ipamorelin trial; any tesamorelin trial outside HIV-associated lipodystrophy long enough to settle its long-term cardiovascular safety, which the label says "has not been established"; and any comparison of compounded or research-market product with the approved EGRIFTA formulations. Nothing here is a recommendation; a decision about either belongs with a clinician.
Sources and dates
Read 2026-09-24: EGRIFTA SV prescribing information via openFDA (indications, dosage, contraindications, warnings, adverse reactions table 1, immunogenicity section 12.6, clinical studies tables 2 and 3); openFDA label listing for tesamorelin (EGRIFTA SV and WR, both effective 2026-07-29); PubMed abstracts of Beck et al. 2014 (PMID 25331030) and Raun et al. 1998 (PMID 9849822); FAERS via the openFDA drug event endpoint (tesamorelin and ipamorelin totals, ipamorelin reaction counts); ClinicalTrials.gov API v2 intervention search for tesamorelin. Gobburu 1999, the Helsinn registrations and FDA's category 2 wording as recorded on our ipamorelin pages (read 2026-09-05 and 2026-09-23). Corrections go to the contact page.