Overview
Tesamorelin is a growth hormone-related peptide. Synthetic GHRH analog with trans-3-hexenoic acid modification.
With a half-life of ~26 minutes, Tesamorelin requires daily administration in most observed protocols. Administered via SubQ injection, it has a bioavailability of approximately 95% via its primary route.
Half-life approximately 26 minutes. FDA-approved (brand: Egrifta). Subcutaneous administration. One-compartment model.
Mechanism of Action
Tesamorelin's pharmacological activity involves the following key pathways:
GHRH Receptor Activation
Tesamorelin binds to growth hormone-releasing hormone (GHRH) receptors on somatotroph cells in the anterior pituitary, stimulating GH synthesis and secretion.
Pulsatile GH Release
Activation of GHRH receptors promotes GH release in a pulsatile pattern that more closely mimics physiological secretion compared to exogenous GH administration.
Dosing Protocols
The following protocols represent commonly observed dosing patterns. These are observational summaries, not recommendations.
Dose
2000 mcg/week
Route
Subcutaneous
Frequency
2-3 times daily
Duration
4-12 weeks
Reconstitution Steps
Tesamorelin is supplied as a lyophilized (freeze-dried) powder and requires reconstitution before use. Common vial sizes: 1 mg, 2 mg, 5 mg, 10 mg.
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1
Gather supplies
You will need a vial of lyophilized tesamorelin powder, bacteriostatic water (BAC water), an insulin syringe (0.5 mL or 1 mL), and two alcohol swabs. Tesamorelin is a delicate peptide — handle gently and avoid vigorous shaking.
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2
Clean the vial tops
Wipe the rubber stoppers of both the tesamorelin vial and the BAC water vial with separate alcohol swabs. Allow to air-dry for at least 10 seconds before inserting any needle.
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3
Draw bacteriostatic water
For a standard 2 mg vial, draw 2 mL of BAC water into the syringe. This produces a working concentration of 1 mg/mL (1,000 mcg/mL), which gives straightforward dose math for the standard 2 mg daily protocol.
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4
Add water slowly against the glass wall
Insert the needle at an angle and inject BAC water slowly along the inner glass wall of the vial — not directly onto the powder. This prevents foaming and protects peptide integrity during dissolution.
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5
Roll gently to dissolve
Roll the vial slowly between your palms for 20–30 seconds until the powder is fully in solution. The reconstituted solution should be clear and colorless — discard if cloudy or if visible particulates remain.
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6
Label and store
Label with the date of reconstitution and refrigerate at 2–8°C immediately. The FDA prescribing information for Egrifta specifies use within 3 hours of reconstitution for the original formulation, though community protocols using BAC water commonly report stability up to 20–30 days when refrigerated.
Quick Reconstitution Math
2 mg vial + 2 mL BAC water = 1,000 mcg/mL. The standard 2 mg daily dose = 2.0 mL (200 units on an insulin syringe), or split across two 1 mL syringes. Use the Milligram reconstitution calculator for custom vial sizes.
Refrigerate at 2–8°C post-reconstitution. The FDA-approved Egrifta formulation specifies a short use window; community BAC water reconstitutions are commonly reported stable for 20–30 days refrigerated. Do not freeze reconstituted solution. Lyophilized powder may be stored frozen at −20°C prior to reconstitution.
Frequently Asked Questions
What is Tesamorelin and what is it FDA approved for?
Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH) composed of the full 44 amino acid GHRH sequence with a hexenoyl trans-3 modification at the N-terminus that protects the molecule from enzymatic degradation. It is FDA-approved under the brand name Egrifta for the reduction of excess visceral abdominal fat in HIV-infected patients with lipodystrophy–making it the only FDA-approved GH secretagogue peptide currently available. Its unique chemical stability results in a longer effective half-life and greater potency compared to earlier GHRH analogs like sermorelin.
How does Tesamorelin differ from Sermorelin and CJC-1295?
Tesamorelin is the full-length 44–amino acid GHRH sequence, while sermorelin uses only the first 29 amino acids. The hexenoyl modification at tesamorelin's N-terminus shields it from degradation by the enzyme DPP-4, extending its active duration compared to unmodified GHRH fragments. CJC-1295 (with DAC) achieves extended half-life through albumin binding, while tesamorelin's half-life of approximately 26–38 minutes reflects a moderate middle ground–shorter than DAC-modified peptides but significantly more stable than sermorelin.
What effects does Tesamorelin have on visceral fat?
Clinical trials in HIV-associated lipodystrophy demonstrated that tesamorelin at 2 mg/day reduced visceral adipose tissue (VAT) by approximately 15–18% over 26–52 weeks compared to placebo. Importantly, these effects appear specific to visceral fat rather than subcutaneous fat, distinguishing it from general fat-loss compounds. The reduction in VAT was associated with concurrent increases in IGF-1 and growth hormone levels. Effects are observed to reverse upon discontinuation.
How is Tesamorelin typically dosed?
The FDA-approved dose for Egrifta is 2 mg administered subcutaneously once daily, typically injected into the abdomen. In off-label protocols observed in the community, the same 2 mg daily dose is most commonly reported, though some users observe a 1 mg/day approach for cost management or to assess tolerance. Evening or bedtime injection is commonly preferred to align with the nocturnal GH pulse, though the clinical studies used a morning injection schedule.
Does Tesamorelin increase IGF-1 levels?
Yes–tesamorelin stimulates pituitary GH secretion, which in turn drives hepatic production of IGF-1. Clinical studies documented significant increases in both GH and IGF-1 with 2 mg daily dosing, with IGF-1 elevations typically observable within 2–4 weeks. IGF-1 and IGFBP-3 increases are considered secondary markers of GH axis activation and are used to confirm biological response in clinical settings.
What compounds is Tesamorelin commonly stacked with?
Tesamorelin is commonly paired with Ipamorelin, which targets ghrelin receptors to provide complementary GH pulse amplification alongside tesamorelin's GHRH receptor activity. CJC-1295 is occasionally combined for additive GHRH stimulation, though some protocols consider this redundant given tesamorelin's full–length GHRH structure. BPC-157 is also observed in stacks where joint health and tissue repair are secondary goals alongside body composition optimization.