Tesamorelin: Complete Guide — Benefits, Dosage, Side Effects & Research

What Is Tesamorelin?

Tesamorelin (trade name Egrifta/Egrifta SV) is a synthetic analog of growth hormone-releasing hormone (GHRH) currently FDA-approved for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. Manufactured by Theratechnologies, it is the only GHRH analog with current FDA approval for a therapeutic indication.

Structurally, Tesamorelin is GHRH(1-44) with a trans-3-hexenoic acid modification at the N-terminus, which improves enzymatic stability and extends its biological half-life compared to native GHRH (though it still requires daily injection).

For the biohacking and anti-aging community, Tesamorelin is interesting because it’s one of the few GH-related peptides with Phase III clinical trial data specifically demonstrating visceral fat reduction. While its FDA approval is limited to HIV-lipodystrophy, the mechanism of action (GH-mediated lipolysis) applies broadly, driving off-label interest.

How Does Tesamorelin Work? (Mechanism of Action)

GHRH Receptor Agonism

Like Sermorelin and CJC-1295, Tesamorelin activates the GHRH receptor on pituitary somatotrophs, stimulating endogenous GH release. The resulting GH increase drives:

1. Lipolysis in adipose tissue — particularly visceral (deep abdominal) fat
2. IGF-1 elevation — mediating some of GH’s downstream effects
3. Improved body composition — lean mass preservation with fat reduction

Selective Visceral Fat Reduction

The most clinically significant finding with Tesamorelin is its preferential effect on visceral adipose tissue (VAT) — the metabolically dangerous deep abdominal fat associated with insulin resistance, cardiovascular disease, and inflammation. In clinical trials, Tesamorelin reduced VAT by approximately 15-18% without significantly affecting subcutaneous fat or lean mass.

This visceral fat selectivity is attributed to the higher density of GH receptors and beta-adrenergic receptors on visceral adipocytes compared to subcutaneous fat cells.

Cognitive Effects (Emerging Research)

An unexpected and exciting research direction: Tesamorelin has shown cognitive benefits in preliminary studies. The STAY (Somatotropin, Aging, and Cognition) trial found that Tesamorelin improved executive function and verbal memory in healthy older adults and reduced brain amyloid burden as measured by PET imaging — suggesting potential relevance for Alzheimer’s disease prevention (Baker et al., 2020).

Research & Evidence

Phase III Trials (HIV-Lipodystrophy)

Pivotal Trials (n=816 combined): Two Phase III, double-blind, placebo-controlled trials in HIV patients with excess visceral fat:

• Trunk fat reduction: ~18% decrease in visceral fat vs. placebo (measured by CT scan)
• IGF-1 normalization: Tesamorelin increased IGF-1 levels into the normal range
• Lipid improvements: Modest improvements in triglycerides and total cholesterol
• Lean mass: Slight increase in lean body mass
• Well-tolerated: No significant safety concerns beyond injection site reactions

(Falutz et al., 2007)

Cognitive Function (STAY Trial)

The STAY trial (n=137, randomized, double-blind) in cognitively normal older adults (55-87 years):

• 20 weeks of Tesamorelin vs. placebo
• Executive function improved in the Tesamorelin group
• Verbal memory improved in a subset analysis
• Brain amyloid-beta reduced (measured by PET — significant finding)
• BDNF levels increased in the Tesamorelin group

These findings are preliminary but suggest GH/IGF-1 pathway stimulation may support cognitive health in aging — a hypothesis with broader implications for all GHRH analogs and GH secretagogues (Baker et al., 2020).

NAFLD/NASH (Liver Fat)

Tesamorelin has shown efficacy for reducing hepatic (liver) fat in HIV-positive patients with NAFLD. In a trial, Tesamorelin treatment reduced liver fat fraction by ~37% compared to placebo, with improvement in hepatic fibrosis biomarkers. This suggests utility for metabolic liver disease beyond the HIV population (Stanley et al., 2014).

Comparison to Other GHRH Analogs

Property	Tesamorelin	CJC-1295 (no DAC)	Sermorelin
FDA approved	Yes (HIV lipodystrophy)	No	Former (diagnostic)
Half-life	~26 min	~30 min	~10-20 min
Clinical data	Phase III (hundreds of patients)	Phase I/II	Phase II (pediatric)
Dosing	Daily (2 mg)	2-3x daily	1-2x daily
Visceral fat data	Strong (CT-measured)	Indirect (via GH)	Limited
Cost	High (branded)	Low (research chemical)	Moderate (compounded)

Benefits (Based on Clinical Evidence)

• Visceral fat reduction — ~18% decrease, CT-measured (Phase III data)
• FDA-approved — the strongest regulatory validation of any GHRH analog
• GH/IGF-1 restoration — normalizes age-related decline in GH axis
• Cognitive improvement — emerging evidence for executive function and memory
• Liver fat reduction — significant in NAFLD studies
• Modest lipid improvement — triglycerides, cholesterol
• Well-tolerated — extensive safety data from clinical trials

Dosage Protocols

FDA-Approved Dosing (Egrifta SV)

• Dose: 2 mg subcutaneous injection once daily
• Timing: Fasted (similar to other GHRH analogs)
• Site rotation: Abdomen (recommended)
• Duration: Ongoing, with periodic reassessment

Off-Label/Anti-Aging Protocol

Many anti-aging clinics prescribe Tesamorelin similarly to the approved protocol:

• Dose: 1–2 mg subcutaneously, daily
• Timing: Before bed or morning fasted
• Cycle: Some physicians recommend cycling (e.g., 6 months on, 2 months off)

Reconstitution (Compounded/Research)

For non-branded sources:

• Reconstitute with bacteriostatic water as directed
• Refrigerate after reconstitution
• Inject subcutaneously into the abdomen

Side Effects & Safety

Common Side Effects (from Phase III data)

• Injection site reactions — erythema, pruritus, pain, swelling (most common: ~24%)
• Arthralgia (joint pain) — 13% (GH class effect)
• Myalgia (muscle pain) — 5%
• Peripheral edema — 6% (water retention, GH effect)
• Paresthesia (tingling) — carpal tunnel-like, GH class effect

Serious Adverse Events (Rare)

• Fluid retention — significant in some patients
• New-onset diabetes or worsening glucose control — GH opposes insulin. Fasting glucose and HbA1c should be monitored.
• Hypersensitivity reactions — rare

Monitoring

Given the FDA-approved status, monitoring guidelines exist:

• IGF-1 levels — at baseline and periodically during treatment
• Fasting glucose/HbA1c — GH can worsen insulin resistance
• Periodic assessment of treatment benefit vs. risk

Legal Status

United States

FDA-approved (as Egrifta SV) for HIV-associated lipodystrophy. Available by prescription. Off-label use for anti-aging/body composition is legal with a prescription. Also available through compounding pharmacies and as a research chemical.

WADA

Prohibited — GHRH and its analogs are banned under Section S2.

Frequently Asked Questions

Is Tesamorelin better than CJC-1295 for fat loss? Tesamorelin has the strongest clinical evidence (Phase III data) specifically demonstrating visceral fat reduction. CJC-1295 likely produces similar GH elevation but lacks comparable clinical fat loss data. If evidence quality matters to you, Tesamorelin wins.

Can I get a prescription for Tesamorelin? The FDA-approved indication is HIV-lipodystrophy. Off-label prescription is at physician discretion. Some anti-aging and functional medicine physicians prescribe Tesamorelin for age-related visceral adiposity.

Does Tesamorelin affect insulin sensitivity? Like all GH-elevating compounds, Tesamorelin can reduce insulin sensitivity. In clinical trials, the effect was modest and manageable, but monitoring is important — especially in individuals with pre-existing insulin resistance or diabetes risk.

How does Tesamorelin’s cognitive benefit work? The mechanism is not fully understood. GH/IGF-1 signaling supports neuroplasticity, neuronal survival, and possibly amyloid clearance. The STAY trial’s finding of reduced brain amyloid is particularly intriguing and is being investigated further.

References

1. Falutz J, et al. “Metabolic effects of a growth hormone-releasing factor in patients with HIV.” N Engl J Med. 2007;357(23):2359-70. PubMed
2. Baker LD, et al. “Effects of Growth Hormone–Releasing Hormone on Cognitive Function in Adults With Mild Cognitive Impairment and Healthy Older Adults.” Arch Neurol. 2012;69(11):1420-9. PubMed
3. Stanley TL, et al. “Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation.” JAMA. 2014;312(4):380-9. PubMed
4. Dhillon S. “Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy.” Drugs. 2011;71(8):1071-91.
5. Falutz J, et al. “A placebo-controlled, dose-ranging study of a growth hormone releasing factor in HIV-infected patients with abdominal fat accumulation.” AIDS. 2005;19(12):1279-87.

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