Tesamorelin + Ipamorelin

What Is the Tesamorelin + Ipamorelin Blend?

The tesamorelin + ipamorelin blend is a supplier-defined formulation that combines tesamorelin, a GHRH analogue, with ipamorelin, a selective ghrelin receptor agonist, in one vial. Listings vary widely: some give paired amounts such as 5/5 mg, 10/3 mg, 10/5 mg, 10/10 mg, 12/3 mg or 13/3 mg, while others state only a total of 8 mg or 10 mg. There is no standard ratio.

Tesamorelin is a synthetic analogue of human growth hormone-releasing hormone that stimulates the synthesis and release of endogenous growth hormone^[1]. Ipamorelin is a pentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH2, described in 1998 as the first selective growth hormone secretagogue^[2].

Tesamorelin is an approved drug on its own, but the two-peptide combination is not an approved or standardized product.

Components at a Glance

The blend pairs a large, modified 44-residue GHRH analogue with a five-residue GHS-R1a agonist roughly one-seventh its mass.

Molecular weights are PubChem values (CID 16137828 for tesamorelin and CID 9831659 for ipamorelin).

Why These Compounds Are Studied Together

Tesamorelin and ipamorelin stimulate growth hormone release through two different receptors, which is the basis for grouping them. Published research on this specific combination is limited; the evidence comes from studies of each component.

Two receptor pathways

Tesamorelin acts as a GHRH analogue at the GHRH receptor^[1]. Ipamorelin works through a separate GHRP-like receptor: profiling with GHRP and GHRH antagonists showed it releases GH the way GHRP-6 does, not through the GHRH receptor^[2]. In rats treated with ipamorelin for 15 days, the pituitary GH response to a GHRH challenge was unchanged^[4].

What each component brings to the evidence base

Tesamorelin has controlled human data as a single agent. In two 26-week trials in people with HIV-associated central fat accumulation, it reduced visceral adipose tissue, and the effect reversed after discontinuation^[1]. A later randomized trial reported reductions in visceral and hepatic fat^[5]. Ipamorelin data are mainly preclinical: in swine it raised GH without raising ACTH or cortisol beyond levels seen after GHRH^[2], and in rats it increased longitudinal bone growth^[4].

What has not been studied

No study in the cited literature gives tesamorelin and ipamorelin together. The closest reported pairing is CJC-1295, another GHRH analogue, with ipamorelin, which improved maximum tetanic tension in a mouse model of glucocorticoid-induced muscle loss; the same review notes the finding is limited to animal studies^[6].

Since tesamorelin-to-ipamorelin ratios differ between listings, researchers typically check HPLC and mass spectrometry certificates of analysis that quantify each peptide separately.

Research Status

The tesamorelin + ipamorelin blend has no regulatory approval and is supplied for laboratory research use only. Tesamorelin alone was approved by the FDA in November 2010 for reducing excess abdominal fat in HIV-infected patients with lipodystrophy^[7]. Ipamorelin has not been approved.

A 2026 review places ipamorelin among peptides promoted for muscle growth and fat metabolism, notes that most published studies examine controlled therapeutic regimens rather than combined protocols, and warns that unregulated products are often mislabeled or contaminated^[8]. Sports medicine reviewers add that rigorous human safety data are scarce for many unapproved peptides sold directly to patients^[9].

Evidence quality is uneven. Tesamorelin has phase 3 trial data for one approved indication, ipamorelin is supported mainly by animal and in vitro work, and the combined formulation has no published data.