Ipamorelin vs Sermorelin vs Tesamorelin: differences, evidence and safety

Verdict: Tesamorelin is an FDA-approved drug (Egrifta WR) for excess abdominal fat in adults with HIV lipodystrophy, backed by phase 3 randomized trials. Sermorelin was approved as Geref, but its approvals were withdrawn in 2009. Ipamorelin was never approved, and its one published trial missed its goal.

All three raise the body’s own growth hormone (GH), and all three are prohibited in sport under WADA class S2. The evidence gap between them is large. Tesamorelin has placebo-controlled trials in hundreds of people. Sermorelin’s human data are mostly small or open-label studies from the 1990s. Ipamorelin has a pharmacology study in healthy men and a surgical trial that showed no benefit. Tesamorelin also carries labeled risks: glucose intolerance, fluid retention and raised IGF-1, a growth factor whose long-term effects the label calls unknown.

Item	Ipamorelin	Sermorelin	Tesamorelin
US FDA status	Not approved	Geref approval withdrawn 2009, not for safety reasons (FR 2013)	Approved: Egrifta WR, HIV-associated abdominal fat (label)
Compounding (503A/503B)	Category 2 under 503B, since 2023-09-29 (FDA)	Not on FDA’s Category 2 list	Not on FDA’s Category 2 list; licensed as a biologic (BLA022505)
WADA 2026	Prohibited, S2 (GH secretagogue)	Prohibited, S2 (GHRH analogue)	Prohibited, S2 (GHRH analogue)
Strongest evidence	Human RCT (n=114), negative	Human open-label (n=110 children)	Human RCTs (phase 3) and approved label
Human trials	2 phase 2 (NCT00672074, NCT01280344)	Small studies, mostly before trial registries	Phase 3 and several RCTs (e.g. NCT00123253)
Last checked	2026-09-30	2026-09-30	2026-09-30

Ipamorelin vs sermorelin vs tesamorelin at a glance

Feature	Ipamorelin	Sermorelin	Tesamorelin
What it is	Synthetic five-amino-acid peptide	First 29 amino acids of human GHRH	Stabilized analog of human GHRH
Class	GH secretagogue (ghrelin mimetic)	GHRH analogue	GHRH analogue
Receptor	Ghrelin receptor	GHRH receptor	GHRH receptor
Main research focus	Gut recovery after surgery	GH deficiency in children; aging	HIV abdominal fat; liver fat; cognition
Human evidence	1 published RCT (Beck 2014); 1 PK study (Gobburu 1999)	Open-label and small studies (Thorner 1996)	Phase 3 RCTs (pooled n=806) plus later RCTs
US approval	None	Withdrawn 2009	Approved since 2010
WADA	S2, banned at all times	S2, banned at all times	S2, banned at all times
Routes studied	Intravenous	Subcutaneous	Subcutaneous
Timelines in studies	GH peak about 40 min after infusion	Faster growth by 6 months	Visceral fat change at 26 weeks
Main safety concerns	Little long-term data; compounding purity (FDA)	Little adult data; unregulated products	Glucose intolerance, fluid retention, raised IGF-1

What is ipamorelin?

Ipamorelin is a synthetic pentapeptide (a chain of five amino acids) described in 1998 as the first selective GH secretagogue. In rat pituitary cells it released GH about as strongly as the older peptide GHRP-6. In animals it did not raise ACTH or cortisol, even at doses 200 times higher (Raun 1998) [Lab and Animal]. Its later human development targeted postoperative ileus, a temporary stall of the gut after bowel surgery. That program produced one published phase 2 trial, which found no significant benefit (Beck 2014) [Human RCT, n=114]. Ipamorelin is not approved in the US. It is still on FDA’s Category 2 list for 503B outsourcing facilities (FDA).

What is sermorelin?

Sermorelin is GHRH(1-29), the first 29 amino acids of growth hormone-releasing hormone, the brain’s natural signal for GH release. It works by mimicking that hormone (USADA). FDA approved it as Geref in 1990 as a diagnostic test of the pituitary’s ability to release GH. In 1997 it was approved to treat idiopathic GH deficiency in children with growth failure. The maker discontinued both products in 2008, and FDA withdrew the approvals effective June 18, 2009. In 2013 FDA determined that the withdrawal was not for safety or effectiveness reasons (Federal Register). Today sermorelin is sold through compounding pharmacies and black-market websites, according to USADA.

What is tesamorelin?

Tesamorelin is a stabilized analog of human GHRH (Baker 2012). It is approved in the US as Egrifta WR (earlier Egrifta and Egrifta SV) to reduce excess abdominal fat in adults with HIV and lipodystrophy, an abnormal redistribution of body fat. The label says it is not indicated for weight loss and that its long-term cardiovascular safety has not been established (Approved label). Its first US approval was in 2010, and it is now licensed as a biologic. It is the only one of the three with a current FDA approval.

How do they work differently?

• Ipamorelin: activates the ghrelin receptor (the receptor for the “hunger hormone”) in the pituitary. In animals it released GH without the ACTH and cortisol rise seen with older GH-releasing peptides (Raun 1998) [Animal].
• Sermorelin: activates the GHRH receptor, the same receptor the body’s own GHRH uses (USADA). In older men it raised 24-hour GH and IGF-1 over 14 days, but only at the higher of two doses. After that, their levels no longer differed significantly from young men’s (Corpas 1992) [Human, n=10 older men].
• Tesamorelin: activates the GHRH receptor as a stabilized analog. In a 20-week trial in older adults, IGF-1 rose 117% and body fat fell 7.4% (Baker 2012) [Human RCT, n=152].
• Human pharmacology: after one intravenous infusion, ipamorelin produced a single GH pulse that peaked at about 0.67 hours. Its terminal half-life was 2 hours (Gobburu 1999) [Human PK study, 8 healthy men per dose level].

Evidence head-to-head

Each cell gives the best evidence found for that outcome, with its level. “None found” means a search of PubMed and ClinicalTrials.gov turned up no human study of that outcome.

Outcome	Ipamorelin	Sermorelin	Tesamorelin
Raises GH	Human PK (Gobburu 1999)	Human, n=10 (Corpas 1992)	Human RCT: IGF-1 +81% (Falutz 2007)
Visceral (belly) fat	None found	Human, n=11: no body-composition change (Vittone 1997)	Human RCT, n=412: −15.2% vs +5.0% (Falutz 2007)
Liver fat	None found	None found	Human RCT, n=61 (Stanley 2019)
Muscle strength	None found	Human, n=11: gains on 2 lifts (Vittone 1997)	None found
Cognition	None found	None found	Human RCT, n=152 (Baker 2012)
Child growth	None found	Human open-label, n=110 (Thorner 1996)	None found
Gut recovery after surgery	Human RCT, n=114: no benefit (Beck 2014)	None found	None found
Blood sugar safety	None found	Human: no fasting glucose change (Thorner 1996)	Human RCT, n=53 type 2 diabetes (Clemmons 2017)

Some details behind the table:

• Ipamorelin after surgery: the median time to tolerating solid food was 25.3 hours with ipamorelin and 32.6 hours with placebo. The difference was not statistically significant (p=0.15) (Beck 2014) [Human RCT, n=114].
• Tesamorelin and liver fat: after 12 months, 35% of people on tesamorelin and 4% on placebo had liver fat below 5% (Stanley 2019) [Human RCT, n=61].
• Tesamorelin pooled phase 3 data: visceral fat changed by −24 cm² with tesamorelin and +2 cm² with placebo, and triglycerides fell (Falutz 2010) [Human RCT, n=806].
• Sermorelin in older men: it raised nighttime GH but did not change IGF-1 (Vittone 1997) [Human, n=11].

Which fits which goal?

• Belly fat and liver fat: tesamorelin has more evidence, from phase 3 and later RCTs, but only in people with HIV (Stanley 2014) [Human RCT, n=50]. Neither of the other two has a controlled human fat-loss trial.
• Weight loss in general: none of the three is approved for weight loss, and the tesamorelin label describes a weight-neutral effect (Approved label). Drugs with weight-loss trial data are compared in retatrutide vs tirzepatide vs semaglutide.
• GH deficiency in children: sermorelin has more evidence, as a former approved treatment (Federal Register).
• Aging, muscle and “anti-aging” use: the evidence is thin for all three. It consists of small sermorelin studies in older men and one tesamorelin cognition trial in older adults (Baker 2012).
• Ipamorelin: no controlled human trial has shown a positive result for any outcome.

These are statements about evidence, not recommendations. A clinician is the person to decide whether any treatment that acts on growth hormone fits a given person.

Can they be combined?

Ipamorelin is most often discussed alongside CJC-1295, another GHRH analogue. The evidence on that pairing is covered in our review of the peptides Joe Rogan has discussed. FDA’s compounding page records safety concerns for both. Ipamorelin remains in Category 2 for 503B. CJC-1295’s nomination was withdrawn, but the page still cites reported serious adverse events for it, including increased heart rate (FDA). No controlled human study has tested any pairing of the three peptides in this comparison.

Safety and regulatory status

United States

• Ipamorelin: not approved. FDA placed ipamorelin acetate in Category 2 for 503B outsourcing facilities on September 29, 2023, and it is still there. FDA’s stated concern is a “risk for immunogenicity” (immune reactions) from aggregation or peptide-related impurities (FDA Category 2 page). The FDA page also lists its nomination as withdrawn, the same route other peptides took (see our BPC-157 vs TB-500 comparison). In the surgery trial, adverse events were similar with ipamorelin (87.5%) and placebo (94.8%) (Beck 2014) [Human RCT, n=114]. The published human data cover only single infusions and courses of up to 7 days.
• Sermorelin: Geref’s approvals were withdrawn in 2009. FDA found that this was not for safety or effectiveness reasons (Federal Register). In the pediatric study it was well tolerated, with no adverse changes in biochemical or hormone tests (Thorner 1996) [Human open-label, n=110]. No long-term controlled safety data in adults were found.
• Tesamorelin: approved (Egrifta WR). The label lists these risks:
  • glucose intolerance, with a diabetes hazard ratio of 3.3
  • fluid retention, which can cause swelling, joint pain or carpal tunnel syndrome
  • raised IGF-1, with unknown long-term effects
  • hypersensitivity reactions

  It is contraindicated in pregnancy and in people with active malignancy. The most common reactions were redness at the site where the drug was given (17%) and joint pain (13%) (Approved label). In people with type 2 diabetes, 12 weeks of tesamorelin did not worsen glucose control (Clemmons 2017) [Human RCT, n=53]. FDA treats tesamorelin sold as a “research” product as an unapproved new drug (FDA warning letter).

Outside the tesamorelin label, no established human dose exists for any of the three.

European Union

Tesamorelin’s EU application was withdrawn in 2012, after the EMA’s human-medicines committee (CHMP) found the data did not allow it to conclude a positive benefit-risk balance (EMA).

Sport

The 2026 WADA Prohibited List bans all three at all times under S2 “growth hormone releasing factors”. It names sermorelin and tesamorelin as GHRH analogues and ipamorelin as a GH secretagogue (WADA 2026 list). According to USADA, a therapeutic use exemption for sermorelin is highly unlikely, because it is not a first-line treatment for GH deficiency (USADA).

How long do effects take in studies?

• Ipamorelin: GH peaked about 40 minutes (0.67 hours) after a single infusion in healthy men (Gobburu 1999) [Human PK].
• Sermorelin: in children with GH deficiency, height velocity (growth speed) rose from 4.1 cm/year at baseline to 8.0 cm/year at 6 months and 7.2 cm/year at 12 months (Thorner 1996) [Human open-label, n=110]. In older men, GH and IGF-1 rose within 14 days (Corpas 1992) [Human, n=10].
• Tesamorelin: visceral fat was measured at 26 weeks. After a switch to placebo, it rose again by week 52 (Approved label). Liver fat fell by 6 months (Stanley 2014) [Human RCT, n=50]. Cognitive effects were measured at 20 weeks (Baker 2012) [Human RCT, n=152].