What is Tesamorelin? An FDA-approved peptide for visceral fat

Most peptides in concierge medicine are prescribed off-label — backed by clinical evidence, but never reviewed and approved by the FDA for a specific indication. Tesamorelin is the exception. It carries a full FDA approval (under the brand name Egrifta) for a narrow indication, and over the last decade it's become one of the most-prescribed peptides in metabolic medicine for what it actually does well: reducing visceral fat.

Here's what it is, what the evidence supports, and how it fits into a real protocol.

What is Tesamorelin?

Tesamorelin is a synthetic analog of growth-hormone-releasing hormone (GHRH) — a 44-amino-acid peptide stabilized to resist rapid breakdown in the body, giving it a longer effective signal than sermorelin's 29-amino-acid GHRH analog.

Mechanistically, it does what every GHRH peptide does — bind receptors on the anterior pituitary and trigger the release of your body's own growth hormone. What sets it apart is the potency: tesamorelin produces a stronger and more sustained GH pulse than sermorelin at therapeutic doses.

The FDA-approved indication

Tesamorelin is approved for the reduction of excess visceral fat in HIV-infected patients with lipodystrophy — a body-composition condition driven by long-term antiretroviral therapy. The clinical trial data that led to approval showed an average 15–18% reduction in visceral adipose tissue (VAT) over 26 weeks at the standard 2mg daily dose, with corresponding improvements in triglycerides, adiponectin, and fasting glucose.

The visceral-fat-reduction effect doesn't require HIV- related lipodystrophy to work. It's the underlying mechanism — increased GH pulse, improved lipolysis at visceral depots — that produces the body-composition change. That's why metabolic clinicians have been prescribing tesamorelin off-label for non-HIV patients with abdominal-pattern adiposity, insulin resistance, and visceral-fat-driven metabolic dysfunction for years.

Tesamorelin vs Sermorelin vs CJC/Ipamorelin

All three stimulate endogenous growth hormone release, but they do it with different intensities and clinical fits.

• Sermorelin: gentlest GH pulse, shortest half-life, lowest cost. Entry-level peptide for sleep, recovery, body composition. Modest visible response over 3–6 months.
• CJC-1295 / Ipamorelin: stronger combined GHRH + GHRP pulse via dual receptor activation. Workhorse protocol for body composition, recovery, sleep depth. Doesn't specifically target visceral fat.
• Tesamorelin: stronger sustained GHRH signal than sermorelin. Specifically studied for visceral fat reduction. Used by patients prioritizing metabolic recomposition rather than general aging or recovery.

The clinical question isn't “which is best?” — it's “which fits your goal?” A patient targeting deep sleep and lean-mass recovery might do best on CJC/Ipamorelin. A patient with insulin resistance and a stubborn visceral pattern despite training and dietary work might do best on tesamorelin.

How it's dosed

The FDA-approved tesamorelin protocol is 2mg subcutaneously, once daily, at bedtime. Off-label metabolic protocols often use 1mg daily as a starting dose with the option to escalate based on response and tolerability — IGF-1, fasting glucose, and visceral fat measured by waist circumference or DEXA at week 8 and 16.

Cycles versus continuous: Egrifta's clinical trials ran continuous dosing for 26 weeks. Concierge practice typically uses 4–6 month cycles followed by a 2–3 month off-period to avoid pituitary downregulation, repeated as needed.

Who fits, who doesn't

• Good candidates: patients with documented visceral-fat-driven metabolic dysfunction, insulin resistance, or abdominal-pattern adiposity that hasn't responded to lifestyle intervention. Patients already optimized on sleep, training, and base hormone protocols who want a metabolic-recomposition lever.
• Caution required: patients with active or recent cancer history (the GH-IGF-1 axis modulation has theoretical concerns), uncontrolled diabetes, or severe insulin resistance with elevated HbA1c — tesamorelin can transiently worsen glucose control in the first 8 weeks.
• Not a fit: patients looking for a sleep peptide (sermorelin or CJC/Ipamorelin are better choices), patients seeking weight loss without metabolic indication (GLP-1 protocols are the right tool), or patients who can't commit to consistent labs and the 4–6 month evaluation window.

What labs to watch

• IGF-1 — confirms the GH pulse is producing downstream effect. Target the upper third of age-adjusted reference range, never above
• Fasting glucose + HbA1c — monitor for transient glycemic disturbance in early weeks
• Lipid panel — improvement in triglycerides is one of the documented effects
• Waist circumference — simplest at-home proxy for visceral fat. DEXA scan available if patient wants quantitative tracking

How Vektor approaches Tesamorelin

We prescribe tesamorelin selectively — the indication has to fit. That means visceral-pattern adiposity confirmed clinically, base metabolic work already in motion, and the patient committed to the labs and check-in cadence the protocol requires. Sourcing is through our 503A pharmacy partner with proper Egrifta-equivalent formulation.

For most patients, tesamorelin is layered on top of an existing protocol — not a first peptide. New peptide patients usually start on sermorelin or CJC/Ipamorelin. Tesamorelin enters the picture when the metabolic indication is clear.