Hormone research

Tesamorelin vs Ipamorelin: Key Differences in the Research

Tesamorelin vs ipamorelin comes down to two different switches. Both sit on the same growth hormone pathway. Tesamorelin is a 44 amino acid copy of the brain hormone GHRH. It became a prescription medicine in the United States for one narrow use. Ipamorelin is a five amino acid peptide that acts on the ghrelin receptor. It never became a medicine anywhere we could find.

Updated 26 October 2026. Education for laboratory research. Not medical advice.

At a glance

	Tesamorelin	Ipamorelin
Class	GHRH analogue	Ghrelin receptor agonist (secretagogue)
Receptor	GHRH receptor	Ghrelin receptor, GHS-R1a
Length	44 amino acids	five amino acids
Formula	C221H366N72O67S	C38H49N9O5
Molecular weight	about 5136 g/mol	711.9 g/mol
First key paper	2007 phase 3 trial	1998 discovery paper
Approved medicine	Yes, in the US, for HIV-related belly fat	None found
WADA group	S2.2.4	S2.2.4

The size gap is huge. Tesamorelin is roughly seven times heavier, because it copies a whole hormone. Ipamorelin is a tiny designed molecule.

Sources: Falutz J et al, J Acquir Immune Defic Syndr, 2010. Dhillon S, Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy, Drugs, 2011. Raun K et al, Ipamorelin, the first selective growth hormone secretagogue, Eur J Endocrinol, 1998. PubChem, Tesamorelin, CID 16137828, National Library of Medicine. PubChem, Ipamorelin, CID 9831659, National Library of Medicine. World Anti-Doping Agency, Prohibited List, S2.2.4 growth hormone releasing factors, read 26 October 2026. Falutz J et al, Metabolic effects of a growth hormone-releasing factor in patients with HIV, N Engl J Med, 2007.

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What is tesamorelin?

Tesamorelin is a lab-made copy of GHRH, short for growth hormone releasing hormone. It uses the full 44 amino acid chain of the natural hormone. It does the same job as natural GHRH. It tells the pituitary gland to release growth hormone.

The product page for our tesamorelin research vials covers the vial itself. This guide stays on the comparison.

Sources: Falutz J et al, J Acquir Immune Defic Syndr, 2010. Dhillon S, Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy, Drugs, 2011.

What is ipamorelin?

Ipamorelin is a chain of five amino acids. It was built in a drug chemistry programme in the 1990s. The 1998 paper called it the first selective compound that triggers growth hormone release. In the paper's animal tests, it did release growth hormone. Several other pituitary hormones the team measured did not change. Older compounds in the same family were less selective.

Glow Labs lists ipamorelin on its own as stocking soon. It is also one half of the CJC-1295 / Ipamorelin blend.

Sources: Raun K et al, Ipamorelin, the first selective growth hormone secretagogue, Eur J Endocrinol, 1998.

How they work

Both end in the same place, the pituitary gland, but they knock on different doors.

Tesamorelin binds the GHRH receptor. This is the main "release" signal sent from the hypothalamus.
Ipamorelin binds the ghrelin receptor. Ghrelin is a hormone made mostly in the stomach. One of its jobs is to push growth hormone release through its own receptor.

Because the doors are different, scientists treat them as separate tools. One mimics the brain's signal. The other mimics a gut signal.

Sources: Dhillon S, Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy, Drugs, 2011. Raun K et al, Ipamorelin, the first selective growth hormone secretagogue, Eur J Endocrinol, 1998.

Evidence ledger

This table lists the actual human studies, so you can judge for yourself.

Compound	Year	People studied	What was measured	Led to approval?
Tesamorelin	2007	412 adults with HIV and excess belly fat, 26 weeks	Visceral fat by CT scan, blood fats and IGF-1	Yes, in the US
Tesamorelin	2010	404 adults with HIV and excess belly fat, 12 months	Visceral fat by scan, IGF-1, glucose and safety	Yes, in the US
Tesamorelin	2012	402 people from two phase 3 trials who received tesamorelin	Whether changes in visceral fat tracked blood fats and glucose markers	Follow-up analysis
Ipamorelin	1999	8 healthy men at each of 5 levels	How long it stayed in blood and the growth hormone response	No
Ipamorelin	2014	114 adults after bowel surgery	Time until a solid meal was tolerated, plus safety	No

In the 2014 ipamorelin trial, the team found no significant difference from placebo in its key measures.

So the evidence levels differ for a clear reason. Tesamorelin went through large phase 3 trials for one condition. Ipamorelin had small studies and one phase 2 trial that did not meet its goal.

Sources: Falutz J et al, J Acquir Immune Defic Syndr, 2010. Stanley TL et al, Reduction in visceral adiposity is associated with an improved metabolic profile in HIV-infected patients receiving tesamorelin, Clin Infect Dis, 2012. Dhillon S, Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy, Drugs, 2011. Gobburu JV et al, Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers, Pharm Res, 1999. Beck DE et al, Int J Colorectal Dis, 2014. Falutz J et al, Metabolic effects of a growth hormone-releasing factor in patients with HIV, N Engl J Med, 2007.

Approval and sport

In the United States, tesamorelin is approved for one use. It is to reduce excess belly fat in people with HIV who have lipodystrophy. That word means a change in how the body stores fat. It is the only approved use in the review we read.

In Australia, the October 2026 Poisons Standard does not name tesamorelin. It does list growth hormone releasing hormones (GHRHs) as a group in Schedule 4. That is the prescription only schedule. Ipamorelin is named on its own in Schedule 4. Both entries also sit in Appendix D, clause 5. That clause lists poisons that are illegal to hold without authority. A legal prescription is one kind of authority.

Sport Integrity Australia says ipamorelin is in no medicine on the national register. Its full name is the Australian Register of Therapeutic Goods. The World Anti-Doping Agency lists both peptides under S2.2.4. That group covers growth hormone releasing factors. They are banned at all times. Our vials are for lab research only. Our research use notice explains how Glow Labs sells these compounds.

Sources: Dhillon S, Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy, Drugs, 2011. World Anti-Doping Agency, Prohibited List, S2.2.4 growth hormone releasing factors, read 26 October 2026. Sport Integrity Australia, Ipamorelin substance information. Poisons Standard, October 2026 (F2026L01327): Schedule 4 and Appendix D, clause 5, Australian Government legislation register.

Why they are paired

Catalogues often sell a GHRH copy together with a ghrelin receptor peptide. The two hit different receptors on the same gland. The common pairing is CJC-1295 with ipamorelin. Our CJC-1295 + ipamorelin guide covers it in depth, including the DAC question. We found no controlled trial testing tesamorelin and ipamorelin together.

What we stock

Tesamorelin, 10mg vial.
Ipamorelin, 10mg vial, stocking soon.
CJC-1295 / Ipamorelin blend, 10mg vial, sold out, pre-order on WhatsApp.

All arrive as freeze-dried powder for lab use. Keep them sealed, cold and dark until needed. For more, see our guide on storing research peptides.

FAQ

Is tesamorelin better than ipamorelin?

We found no study comparing them. They act on different receptors. Tesamorelin also has far more human trial data. It was tested in large phase 3 trials in adults with HIV. It then became a US medicine. Ipamorelin has a few small human studies and no approval.

Are tesamorelin and ipamorelin the same?

No. Tesamorelin is a 44 amino acid copy of GHRH. Ipamorelin is a much shorter chain of five amino acids. It targets the ghrelin receptor. Their receptors differ.

Are they banned in sport?

Yes. Both are on the World Anti-Doping Agency list under S2.2.4. They are banned at all times.

Can I buy ipamorelin on its own here?

Glow Labs lists a single ipamorelin vial as stocking soon. Until then, it comes inside the CJC-1295 blend, which is also on pre-order.

Sources: Falutz J et al, J Acquir Immune Defic Syndr, 2010. Dhillon S, Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy, Drugs, 2011. Raun K et al, Ipamorelin, the first selective growth hormone secretagogue, Eur J Endocrinol, 1998. World Anti-Doping Agency, Prohibited List, S2.2.4 growth hormone releasing factors, read 26 October 2026.