Tesamorelin
The only FDA-approved GHRH analog, engineered to stimulate the body's own pulsatile growth hormone release and selectively strip away deep visceral abdominal fat.
Tesamorelin is a stabilized synthetic 44-amino-acid analog of human growth hormone-releasing hormone (GHRH) with an N-terminal trans-3-hexenoyl modification that resists DPP-4 degradation and extends its plasma half-life. Marketed as Egrifta by Theratechnologies, it was FDA-approved in 2010 for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy, making it the only GHRH secretagogue to clear full FDA approval. By amplifying endogenous pulsatile GH secretion and downstream hepatic IGF-1 production, it preferentially mobilizes visceral adipose tissue while sparing subcutaneous fat, with pooled Phase 3 trials showing roughly 15-18% visceral fat reduction at 26 weeks.
Class
Synthetic stabilized GHRH(1-44) analog (growth hormone-releasing factor)
Half-life
~26-50 minutes (plasma, subcutaneous)
Routes
Subcutaneous injection
Category
Growth Hormone & Performance
Researched benefits
What it's studied for
Visceral fat reduction
Tesamorelin's signature effect: pooled Phase 3 trials showed approximately 15-18% reduction in visceral adipose tissue (VAT) at 26 weeks versus placebo, CT-measured, sustained through 52 weeks. This is the strongest clinical evidence of any fat-targeted peptide, driven by GH/IGF-1-mediated lipolysis in visceral depots.
Selective sparing of subcutaneous fat
Across all pivotal trials, subcutaneous abdominal fat was largely unchanged while visceral fat fell, reflecting greater sensitivity of visceral adipocytes to GH-mediated lipolysis and higher beta-adrenergic receptor density. This selectivity distinguishes it from general weight-loss agents.
Hepatic (liver) fat reduction
A Phase 2 JAMA trial (Stanley 2014) in HIV patients with NAFLD showed tesamorelin 2 mg/day for 12 months reduced hepatic fat fraction by about 3.6 absolute percentage points versus placebo, with improvements in ALT and NAFLD-activity score, via GH-driven hepatic lipid export.
Preserved pulsatile GH release
Because its half-life is short enough to clear between physiologic GH pulses, tesamorelin amplifies the natural nocturnal GH burst without desensitizing pituitary somatotrophs or overriding somatostatin negative feedback, unlike long-acting continuous secretagogues such as CJC-1295 with DAC.
Physiologic IGF-1 elevation and lean mass preservation
In the pivotal trial IGF-1 rose roughly 1.7-fold (185 to 327 ng/mL by week 26), typically within the age-adjusted reference range, supporting muscle protein synthesis and lean body mass preservation during fat loss.
Potential cognitive support in GH-axis-deficient populations
Pilot data in HIV-associated cognitive impairment (Adrian 2018) suggested improvements in executive function and memory, likely IGF-1-mediated neuroprotection. This remains investigational and outside the approved indication.
Mechanism
How it works
Tesamorelin is human GHRH(1-44) carrying a single N-terminal trans-3-hexenoic acid (trans-3-hexenoyl) modification. That fatty-acid group shields the peptide from cleavage by dipeptidyl peptidase-4 (DPP-4), extending its circulating half-life to roughly 26-50 minutes versus under two minutes for native GHRH. It binds the GHRH receptor (GHRHR), a Class B1 GPCR on anterior pituitary somatotrophs, with affinity comparable to native GHRH but greater effective potency due to prolonged plasma presence.
Receptor activation engages Gs, elevating intracellular cAMP, which activates PKA and phosphorylates CREB. Phospho-CREB upregulates GH-1 gene transcription and mobilizes preformed GH from secretory granules, producing a GH pulse within 15-30 minutes of injection and peaking near 60 minutes. Critically, tesamorelin's short half-life clears between pulses, preserving somatotroph sensitivity, allowing somatostatin-mediated negative feedback to suppress GH between doses, and integrating with the body's circadian nocturnal GH burst. This preserved pulsatility is the mechanistic reason tesamorelin was developable as a long-term therapy where continuously-acting analogs raised safety concerns.
Each GH pulse drives hepatic IGF-1 synthesis, peaking around 24 hours post-dose. IGF-1 and GH mediate the downstream metabolic effects: preferential lipolysis in visceral adipose tissue, hepatic triglyceride mobilization and reduced steatosis, muscle protein synthesis for lean mass preservation, and connective-tissue anabolism. The preferential visceral effect reflects higher beta-adrenergic receptor density on visceral adipocytes, their greater sensitivity to GH-mediated lipolysis, and portal delivery of visceral free fatty acids to the liver for oxidation.
Because it works upstream on the GHRH axis rather than directly supplying growth hormone, tesamorelin amplifies the body's own regulated GH output rather than imposing tonic supraphysiological levels, and it carries no FDA black-box warning unlike recombinant somatropin. It nonetheless shares the GH/IGF-1 safety envelope, so IGF-1, glucose, and HbA1c require monitoring.
Dosing protocols
Dosing & administration
Dosing reflects protocols reported in research and community literature for educational purposes. It is not medical advice or a recommendation. Most peptides here are not approved for human use.
Reconstitution
FDA-approved commercial Egrifta / Egrifta SV: follow the package insert exactly (typical 2 mg vial + 2.1 mL supplied 0.9% sodium chloride = ~0.95 mg/mL, inject the entire 2.1 mL, single-use). For compounded/research-use material a common scheme is a 5 mg vial + 2.5 mL bacteriostatic water = 2 mg/mL (a 2 mg dose = 1 mL = 100 units on an insulin syringe). Inject BAC water down the vial wall, swirl gently (do not shake), and allow 2-5 minutes to fully dissolve since tesamorelin dissolves slower than ipamorelin. Solution should be clear and colorless. Store refrigerated (2-8 C), do not freeze; commercial saline-reconstituted product is single-use per label while compounded BAC-water solution is conservatively stable ~7-10 days refrigerated.
Beginner (FDA-approved protocol)
- Dose
- 2 mg
- Frequency
- Once daily
- Timing
- Pre-bed, fasted (>=2 hours post-meal)
- Duration
- Weeks 1-12, up to 26 weeks per pivotal trial
- Route
- Subcutaneous (abdominal fat, >=2 inches from navel, rotate sites)
Matches the dose used across all Phase 3 trials. Pre-bed fasted dosing amplifies the nocturnal GH burst; post-meal insulin can cut the GH pulse 50-70%. Expect measurable waist reduction (~1-2 cm) by weeks 8-12 and ~15-18% VAT reduction by 26 weeks. Egrifta SV labeled at 1.4 mg/day and Egrifta WR at 1.28 mg/day are the reformulated brand doses.
Intermediate (Tesa + Ipamorelin stack)
- Dose
- Tesamorelin 2 mg + ipamorelin 200 mcg
- Frequency
- Once daily
- Timing
- Pre-bed, fasted, drawn into the same syringe
- Duration
- 12-24 weeks (12 on / 4 off is conservative)
- Route
- Subcutaneous
Combines GHRHR activation (Gs/cAMP/PKA) with GHS-R1a activation (Gq/PLC/Ca2+) to produce a GH pulse roughly 3-5x larger than either agent alone. Do not exceed 2 mg/day tesamorelin; the dose-response plateaus while edema and carpal-tunnel risk rise.
Advanced (dual-pulse / recomposition)
- Dose
- Tesamorelin 2 mg + ipamorelin 200 mcg pre-bed; optional MOD-GRF 1-29 100 mcg + ipamorelin 200 mcg AM
- Frequency
- One to two GH pulses per day
- Timing
- Nocturnal primary pulse; optional morning fasted secondary pulse
- Duration
- 16-26 weeks on / 4-6 weeks off
- Route
- Subcutaneous
For experienced users with full lab monitoring. Often paired with semaglutide or tirzepatide so GLP-1 drives the caloric deficit while the GHS stack preserves lean mass and targets visceral fat. Off-label NAFLD use follows a 6-12 month 2 mg/day framework with monthly liver enzymes and MRI-PDFF at baseline and 6 months.
- Fasted state is essential: elevated insulin suppresses GH release, and post-meal dosing can blunt the GH pulse by 50-70%. Avoid alcohol within 4 hours of dosing.
- Dose escalation above 2 mg/day (studied to 4 mg) does not produce proportional IGF-1 elevation but increases fluid retention, arthralgia, and carpal tunnel risk.
- Monitoring: baseline IGF-1, fasting glucose, HbA1c, CMP, lipid panel, thyroid, PSA (men >40); recheck IGF-1 and glucose at week 4-6 and a full panel at week 12. Reduce to 1 mg/day if IGF-1 exceeds the age-adjusted upper limit.
- Tesamorelin is suppressive, not curative: discontinuation leads to gradual VAT regain over roughly 6-12 months. Effect plateaus around 26-52 weeks of continuous therapy.
- Do NOT combine with recombinant GH (redundant), CJC-1295 with DAC (contradictory pharmacodynamics), or other GHRH analogs at the same receptor.
- Consider a reduced 1 mg starting dose in age >65 or active T2DM with close glucose monitoring.
Evidence
Research & clinical studies (6)
Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials
Tesamorelin reduced visceral adipose tissue by 10.9% versus a 0.6% increase on placebo over 26 weeks (n=404), with improved trunk-to-limb fat ratio and body image, providing the pivotal evidence for FDA approval.
PMID 20101189Reduction in visceral adipose tissue and improvements in liver fat with tesamorelin in HIV patients with NAFLD
Tesamorelin 2 mg/day for 12 months reduced hepatic fat fraction by about 3.6 absolute percentage points versus placebo, with reductions in ALT and NAFLD-activity score.
Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives
Therapeutic peptides including GHRH analogs show promise for metabolic and endocrine conditions, though many newer peptides still lack sufficient human safety data.
PMID 42123471Combined antiretroviral therapy with low- or normal-protein, high-calorie diets appears to induce significant deleterious electrocardiographic changes in a rodent model
In rodents, antiretroviral therapy plus calorie-dense diets induced ECG abnormalities and myocardial fibrosis, and tesamorelin co-administration prevented these cardiac effects.
PMID 42018810Injectable Peptides in Sports Medicine: A Structured Narrative Review of Evidence, Safety, and Antidoping Implications
Tesamorelin remains investigational for musculoskeletal applications with uncertain safety and product-quality concerns, and faces widespread anti-doping restrictions.
PMID 42160466Differing Presentations of Excess Visceral Abdominal Fat in People Living With HIV: Two Clinical Cases Highlighting Distinct Therapeutic Pathways With Tesamorelin and GLP-1 Receptor Agonists
Tesamorelin selectively reduced visceral fat in a nonobese HIV patient with central adiposity, while a combination approach was more effective in an obese patient, supporting individualized fat-distribution-based management.
PMID 42139091Combinations
Stacking & blends
Tesamorelin + Ipamorelin
Maximal physiologic GH pulse amplitude with visceral fat targeting
Tesamorelin activates the GHRHR (Gs/cAMP/PKA) pathway while ipamorelin activates the ghrelin receptor GHS-R1a (Gq/PLC/Ca2+); the two converge on somatotrophs to produce a GH pulse roughly 3-5x larger than either alone. Both are dosed pre-bed, fasted, in the same syringe.
Semaglutide + Tesamorelin: Targeted Fat Loss
Dual-mechanism fat loss with lean mass preservation
Semaglutide drives a sustained caloric deficit and improves insulin sensitivity through GLP-1 signaling, while tesamorelin specifically mobilizes deep visceral fat via GHRH agonism. The agents work through non-overlapping pathways on different fat compartments; tesamorelin/ipamorelin helps preserve lean mass lost during GLP-1-induced weight loss.
Dual-pulse GHS stack
Two discrete daily GH pulses for advanced recomposition
A pre-bed tesamorelin + ipamorelin pulse (longer GHRHR occupancy) is paired with a morning fasted MOD-GRF 1-29 + ipamorelin pulse, giving two physiologic GH bursts per day while staying within a pulsatile envelope. For experienced users with full monitoring only.
Safety
Side effects & considerations
Commonly reported effects
Contraindications & cautions
- Active malignancy (GH/IGF-1 may accelerate tumor growth)
- Disruption of the hypothalamic-pituitary axis (pituitary tumor, hypopituitarism, surgery/radiation)
- Pregnancy (category X)
- Active proliferative or severe diabetic retinopathy
- Known hypersensitivity to tesamorelin or mannitol
- Acute critical illness (sepsis, post-surgical critical care)
- History of acromegaly or pituitary adenoma
- Uncontrolled type 2 diabetes (relative; optimize first)
- Severe heart failure (NYHA III-IV, relative)
Tesamorelin carries no FDA black-box warning, unlike recombinant GH, and most effects are dose-dependent and resolve with dose reduction. Tingling/numbness signals excessive IGF-1 elevation and a need to reduce dose. It can acutely impair glucose tolerance, so diabetes and IGF-1 monitoring are required. Long-term (>52 week) cardiovascular safety has not been established, and the multi-year cycling seen at some clinics is outside the studied window. Avoid combining with recombinant GH or other GHRH analogs.
FAQ
Tesamorelin — common questions
What is tesamorelin and what is it approved for?
Tesamorelin is a stabilized synthetic 44-amino-acid GHRH analog with an N-terminal trans-3-hexenoyl modification that resists DPP-4 degradation. It is FDA-approved (2010, as Egrifta / Egrifta SV / Egrifta WR by Theratechnologies) for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy, and is the only GHRH secretagogue with full FDA approval.
How much visceral fat can it reduce?
In the pivotal Phase 3 trials, patients on 2 mg/day lost roughly 15-18% of visceral adipose tissue at 26 weeks (a pooled analysis reported 10.9% vs a 0.6% increase on placebo), sustained through 52 weeks. The effect is preferential for visceral over subcutaneous fat, with waist circumference typically dropping 1-3 cm.
What is the standard dose and timing?
The FDA pivotal-trial dose is 2 mg subcutaneous once daily, pre-bed and fasted (at least 2 hours post-meal). The reformulated brands are labeled lower (Egrifta SV 1.4 mg/day, Egrifta WR 1.28 mg/day). Fasted pre-bed dosing leverages the nocturnal GH burst; escalating above 2 mg/day does not add proportional benefit and raises side effects.
How is it different from CJC-1295 with DAC?
Both activate the GHRH receptor, but tesamorelin has a ~26-50 minute half-life that clears between physiologic GH pulses, preserving pulsatile release and somatostatin negative feedback. CJC-1295 with DAC has a ~6-8 day half-life producing continuous, non-pulsatile GH elevation; that continuous exposure raised safety concerns, which is why tesamorelin became FDA-approvable where CJC-1295-DAC did not.
Is it safer than injecting growth hormone?
Mechanistically it amplifies the body's own pulsatile GH release through the pituitary, preserving negative feedback, and it carries no FDA black-box warning unlike recombinant somatropin. However, both share the GH/IGF-1 safety envelope, so active malignancy, diabetic retinopathy, and pituitary tumors are absolute contraindications for both.
Does it work for general weight loss?
No. The FDA label explicitly states it is not indicated for weight-loss management. Tesamorelin's overall effect on body weight is modest; its documented effect is selective reduction of visceral abdominal fat. General body recomposition and anti-aging use is off-label extrapolation from the HIV-derived evidence base.
Does tesamorelin work for fatty liver (NAFLD)?
Off-label, yes. A Phase 2 JAMA trial (Stanley 2014) in HIV patients showed 2 mg/day for 12 months reduced hepatic fat fraction by about 3.6 absolute percentage points versus placebo, with lower ALT and NAFLD-activity score, via GH-driven hepatic lipid export. The FDA has not approved it for NAFLD.
Is research-grade tesamorelin the same as Egrifta?
No. FDA approval applies only to the prescription Egrifta product. Research-grade tesamorelin sold by third-party labs is a separate supply chain with wider purity variance, potential underdosing, and inconsistent endotoxin control; it is sold for laboratory use only and is not approved for human consumption. Independent HPLC and mass-spec certificates of analysis are the only meaningful purity signals for such material.
