TESAMORELIN

What Is Tesamorelin?

Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH), consisting of the full 44-amino-acid GHRH sequence with a trans-3-hexenoic acid modification at the N-terminus. This modification improves stability and bioavailability compared to endogenous GHRH.

Originally developed and FDA-approved under the brand name Egrifta for the reduction of excess abdominal fat in HIV-positive patients with lipodystrophy, tesamorelin has gained significant research interest for its ability to stimulate natural growth hormone production without suppressing the hypothalamic-pituitary axis.

Mechanism of Action

Tesamorelin binds to GHRH receptors on somatotroph cells in the anterior pituitary gland, stimulating the synthesis and release of endogenous growth hormone through a pulsatile, physiological pattern. Key mechanisms include:

• Activates the GHRH receptor (GHRHR), a G-protein coupled receptor on pituitary somatotrophs
• Triggers cAMP-mediated signaling cascade leading to GH gene transcription and secretion
• Preserves the natural pulsatile pattern of GH release, maintaining negative feedback loops
• Increases IGF-1 levels as a downstream effect of elevated GH
• Reduces visceral adipose tissue through GH-mediated lipolysis

Research Applications

• Visceral fat reduction and body composition optimization
• Age-related growth hormone decline studies
• Cognitive function and memory research (BDNF pathways)
• Lipodystrophy and metabolic syndrome models
• Cardiovascular biomarker research (triglycerides, CRP)
• Sleep quality and recovery studies

Dosing Protocol

Tesamorelin is administered daily via subcutaneous injection, typically in the morning on an empty stomach. The protocol below reflects commonly reported research dosing:

Inject subcutaneously in the abdomen, rotating injection sites. Administer in the morning on an empty stomach for optimal GH pulse. Typical research cycles run 8 – 12 weeks.

Preparation & Storage

Reconstitution

Supplies: peptide vial, bacteriostatic water, insulin syringes (29–31 gauge), alcohol swabs.

1. Clean both vial tops with alcohol swabs and let dry
2. Draw 2 mL of bacteriostatic water into the syringe
3. Insert needle into peptide vial at an angle against the glass wall
4. Let water run slowly down the side – never squirt directly onto powder
5. Gently swirl until fully dissolved – never shake
6. Solution should be clear – discard if cloudy or contains particles

Concentration: 2 mg in 2 mL = 1,000 mcg/mL

Storage

• Unreconstituted: Room temp or refrigerated, stable up to 24 months
• Reconstituted: Refrigerate at 2–8°C (36–46°F), use within 4–6 weeks
• Protect from direct sunlight and heat
• Do not freeze reconstituted solution

Cycling

Typical research cycle: 8–12 weeks. Results generally reported within 4–8 weeks.