Tesamorelin
Growth Hormone Secretagogue (GHRH Analogue)approvedAlso known as: Egrifta, TH9507, Trans-3-hexenoic acid-GHRH(1-44)-NH2
An FDA-approved synthetic analogue of growth hormone-releasing hormone (GHRH) with a trans-3-hexenoic acid modification, indicated for HIV-associated lipodystrophy and studied for cognitive benefits and visceral fat reduction.
Overview
Tesamorelin is a synthetic 44-amino acid analogue of human growth hormone-releasing hormone (GHRH) with a trans-3-hexenoic acid group attached to the tyrosine at position 1, which enhances its stability and bioactivity. It is the only GHRH analogue approved by the FDA (2010) and is marketed under the brand name Egrifta for the reduction of excess abdominal (visceral) fat in HIV-infected patients with lipodystrophy. Tesamorelin works by stimulating the anterior pituitary gland to produce and release endogenous growth hormone in a pulsatile, physiological manner. This distinguishes it from exogenous GH administration, as the body's natural feedback mechanisms remain intact, reducing the risk of supraphysiological GH levels. Beyond its FDA-approved indication, Tesamorelin has gained significant popularity in the anti-aging and longevity communities for visceral fat reduction, body composition improvement, and potential cognitive benefits. Studies have shown it can reduce visceral adipose tissue by 15-20% and may improve cognitive function in older adults at risk for Alzheimer's disease by modulating brain amyloid and improving executive function.
Mechanism of Action
Tesamorelin acts through the GHRH receptor pathway: (1) Binds to GHRH receptors on anterior pituitary somatotroph cells, stimulating synthesis and secretion of endogenous growth hormone; (2) The trans-3-hexenoic acid modification protects against N-terminal enzymatic degradation, increasing half-life and receptor binding affinity; (3) Maintains pulsatile GH release patterns, preserving normal hypothalamic-pituitary feedback; (4) Elevated GH stimulates hepatic IGF-1 production, which mediates many downstream effects; (5) GH and IGF-1 promote lipolysis preferentially in visceral adipose tissue; (6) GH modulates lipid metabolism, reducing triglycerides and improving lipid profiles; (7) IGF-1 signaling in the brain may support neuronal health and cognitive function; (8) Unlike exogenous GH, does not suppress endogenous GH production or cause pituitary downregulation.
Molecular Formula
C221H366N72O67S1
Molecular Weight
5135.9 g/mol
Sequence
Modified GHRH(1-44)-NH2 with trans-3-hexenoic acid at Tyr1
Dosage Protocols
Dose Range
2mg – 2mg
Frequency
Once daily
Route
subcutaneous
Cycle Length
Ongoing, with periodic reassessment
FDA-approved dose is 2mg daily by subcutaneous injection in the abdomen. Inject at the same time each day, rotating injection sites. Results typically visible after 3-6 months of consistent use.
Source: FDA prescribing information (Egrifta SV)
Side Effects
| Effect | Severity |
|---|---|
| Injection site reactions | mild |
| Arthralgia | mild |
| Peripheral edema | mild |
| Paresthesia | mild |
| Nausea | mild |
| Carpal tunnel symptoms | moderate |
| Hyperglycemia | moderate |
Pros & Cons
FDA-approved medication with extensive clinical trial safety and efficacy data
Stimulates natural GH production with preserved pulsatile release and feedback regulation
Clinically proven to reduce visceral adipose tissue by 15-20%
Promising cognitive benefits shown in studies of older adults at risk for Alzheimer's
Does not suppress endogenous GH production like exogenous GH administration
Expensive, especially the branded Egrifta product ($800-1500+/month)
Requires daily subcutaneous injections for optimal results
GH-related side effects (joint pain, edema, insulin resistance) can occur
Fat loss reverses upon discontinuation; ongoing use needed for sustained results
Contraindicated in patients with active malignancy due to GH/IGF-1 elevation
Research Studies
Legal Status
FDA-approved (2010) for HIV-associated lipodystrophy under the brand name Egrifta/Egrifta SV. Prescription required. Off-label use is common. Available through specialty pharmacies and compounding pharmacies.
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