Has Tesamorelin + Ipamorelin been tested in humans?

Not as a combination. Tesamorelin has large trials in adults with HIV and ipamorelin has limited human data, but no published study has tested them together.

Why combine tesamorelin with ipamorelin?

They act on different receptors that both trigger growth hormone release. Human studies of other GHRH and ghrelin-type pairings found a larger release together than apart.

Is tesamorelin stronger than CJC-1295?

There are no head-to-head studies. Tesamorelin is the better-studied of the two in humans, while CJC-1295 with DAC lasts much longer in the body.

Tesamorelin + Ipamorelin: What the Stack Is, Research and Side Effects

The peptides in this stack

Tesamorelin

What is Tesamorelin + Ipamorelin?

Tesamorelin is the full 44-amino-acid sequence of human growth hormone-releasing hormone (GHRH) with a small protective chemical group attached, which slows its breakdown. Ipamorelin is a five-amino-acid peptide developed by Novo Nordisk researchers in the 1990s that mimics ghrelin, the hunger hormone that also triggers growth hormone release. In animal studies it was selective, with little effect on the stress hormone cortisol.

Neither peptide is growth hormone. Both prompt the pituitary to release more of its own, which keeps the body's feedback in play. The pairing follows the same logic as CJC-1295 + Ipamorelin and Sermorelin + Ipamorelin, but uses tesamorelin, the GHRH analog with the most human research, as the GHRH half.

How does Tesamorelin + Ipamorelin work?

Growth hormone release has two main pushes and one brake. GHRH from the hypothalamus is one push, ghrelin is the other, and somatostatin is the brake. Tesamorelin acts on the GHRH receptor in the pituitary. Ipamorelin acts on the ghrelin receptor, known as the growth hormone secretagogue receptor, and appears to counter somatostatin. It is often said that one peptide makes growth hormone and the other releases it, but in reality both promote release, through separate routes.

Human studies from the 1980s and 1990s showed that a GHRH given together with a ghrelin-type peptide, such as GHRP-6 or GHRP-2, produced a larger growth hormone release than either alone. Those studies did not use tesamorelin or ipamorelin, so the size of any combined effect for this pair is unknown.

Mixing it for research?

Tesamorelin + Ipamorelin reconstitution chart: how much bacteriostatic water to add to a 8 mg (6/2) vial and how many units each amount is, with Matthew’s step-by-step video.

See the mixing chart

Tesamorelin + Ipamorelin vs CJC-1295 + Ipamorelin

The two stacks share ipamorelin and differ in the GHRH half. In CJC-1295 + Ipamorelin, that half is usually MOD-GRF 1-29, a modified 29-amino-acid fragment of GHRH with very little published human research. Tesamorelin has large placebo-controlled trials, an approval for one condition and a well-described side effect profile. That makes it the better-studied half, though no study has compared the two stacks or shown that either combination does more than its parts.

What has research looked at?

The evidence is uneven. Tesamorelin is one of the better-studied peptides in this library, though mostly in people with HIV, while ipamorelin has little human data and the stack itself has none. Claims of extra fat loss or muscle from the pairing come from theory and user reports.

Tesamorelin and visceral fat: Two large placebo-controlled trials in adults with HIV-associated lipodystrophy found reduced visceral fat on CT scans. Much of it returned after treatment stopped.
Tesamorelin, liver and brain: Trials in people with HIV reported less liver fat, and a randomized trial in older adults reported better scores on tests of executive function.
Ipamorelin in animals: Animal studies showed growth hormone release without major rises in cortisol, and rat studies reported increases in body weight and bone mineral content.
Ipamorelin in humans: Human studies measured its effect on growth hormone, and a trial after bowel surgery found no clear benefit over placebo for gut recovery.
The combination: No published trial has tested tesamorelin and ipamorelin together.

Side effects and cautions

Tesamorelin's side effects are well described from its trials, while ipamorelin's are less well characterized. Since both raise growth hormone and IGF-1, combining them could make growth hormone-related effects more likely. Tesamorelin's labeling also advises against use in pregnancy and in people with active cancer or a disrupted pituitary system. Talk to a qualified clinician about any growth hormone-related compound.

Joint and muscle pain: Joint pain, limb pain and muscle aches were common in tesamorelin trials.
Injection-site reactions: Redness, itching or pain where the peptides are injected are frequently reported.
Fluid retention: Swelling of the hands and feet, tingling and carpal tunnel-type symptoms can occur with higher growth hormone.
Blood sugar: Higher growth hormone can reduce insulin sensitivity, and tesamorelin raised blood sugar in some trial participants.
Cancer history: Because IGF-1 promotes cell growth, these compounds are generally avoided by people with active cancer, and any past history of cancer calls for careful review.