Side-by-side · Research reference
SermorelinvsTesamorelin
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
APhase 3Reviewed14/43 cited
BFDA-ApprovedVerified27/68 cited
Sermorelin
GHRH 1-29 fragment · Short-acting
SQ · Pre-sleep · 1×/day
Tesamorelin
GHRH Analogue · FDA-Approved
SQ · Abdomen · Once Daily
01Mechanism of Action
Parameter
Sermorelin
Tesamorelin
Primary target
Pituitary GHRH receptorWalker 1994
Hypothalamic GHRH receptorsEGRIFTA® (tesamorelin for inje 2010
Pathway
GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994
GHRH → Pituitary GH release → Liver IGF-1 synthesisFalutz 2007
Downstream effect
Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013
Increased GH pulsatility, elevated IGF-1, lipolysis of visceral adipose tissueFalutz 2010
Feedback intact?
Yes — short pulse preserves feedback
Yes — physiological pulsatility preserved
Origin
Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994
Synthetic 44-AA GHRH analogue with trans-3-hexenoic-acid modification for stabilityEGRIFTA® (tesamorelin for inje 2010
02Dosage Protocols
Parameter
Sermorelin
Tesamorelin
Standard dose
100–500 mcg per injectionMolteno 2013
2 mg / dayEGRIFTA® (tesamorelin for inje 2010
FDA-approved protocol.
Frequency
Once daily, pre-sleep
Once daily (morning or pre-sleep)
Aligns with natural GH pulse.
Lower / starter dose
100 mcg per dose
1 mg / dayFalutz 2010
1 mg still produces significant IGF-1 elevation.
Evidence basis
Phase 3 (Geref pediatric); clinical practiceWalker 1994Molteno 2013
RCT / FDA-approvedFalutz 2007Falutz 2010
Duration
8–12 weeks per cycle
12–52 weeks
VAT returns within months of stopping.
Reconstitution
Bacteriostatic water
Sterile water per labeling
Preserved at 2–8 °C after reconstitution.
Timing
Pre-sleep, fasted preferred
Empty stomach, pre-sleep preferred
Half-life
~12 min (plasma)Molteno 2013
Shorter than tesamorelin (~26 min) — simpler GHRH analogue.
~26 min (plasma)EGRIFTA® (tesamorelin for inje 2010
Modified vs native GHRH (7 min t½).
03Metabolic / Fat Loss Evidence
Parameter
Sermorelin
Tesamorelin
Primary fat target
—
Visceral adipose tissue (VAT) — abdominal
Effect on lean mass
—
Modest lean mass preservation / slight increase
Effect reversibility
—
VAT returns within months of stopping
Key publication
—
Falutz et al. NEJM 2007 · Falutz JCEM 2010 · FDA approval 2010Falutz 2007Falutz 2010EGRIFTA® (tesamorelin for inje 2010
04Side Effects & Safety
Parameter
Sermorelin
Tesamorelin
Injection site reaction
Mild erythema, transient pain
Erythema, pruritus, redness (common)
Flushing / headache
Common transient effect
—
IGF-1 elevation
Modest at standard doses
Dose-dependent; supraphysiological levels = discontinue
Cancer risk
Contraindicated in active malignancy (GH/IGF-1 axis)
Contraindicated in active malignancy (GH/IGF-1 axis); theoretical tumour growth riskEGRIFTA® (tesamorelin for inje 2010
Glucose handling
Generally neutral
—
Fluid retention / Edema
—
Peripheral edema, arthralgia, carpal tunnel (GH-axis effect)
Antibody formation
—
~50% at 26 weeks; non-neutralising in most; rare hypersensitivity (<1%)Sévigny 2018
GI symptoms
—
Nausea, diarrhea (mild, transient)
Absolute Contraindications
Sermorelin
- ·Active malignancy
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
Tesamorelin
- ·Active malignancy or history of treated cancer
- ·Pregnancy
- ·Hypersensitivity to tesamorelin or mannitol
- ·Disruption of hypothalamic-pituitary axis (trauma, tumour, radiation)
Relative Contraindications
Sermorelin
- ·Untreated diabetes
Tesamorelin
- ·Untreated diabetes (monitor HbA1c)
- ·Severe carpal tunnel syndrome
- ·Acute critical illness
05Administration Protocol
Parameter
Sermorelin
Tesamorelin
1. Reconstitution
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.
Add 2.1 mL sterile water to 2 mg lyophilised vial. Roll gently — do not shake. Solution should be clear.
2. Injection site
SQ — abdomen or thigh. Rotate sites.
Subcutaneous — abdomen preferred. Rotate sites (avoid same spot within 2 cm). Avoid navel and waistband area.
3. Timing
Pre-sleep, fasted.
Once daily. Preferred: evening, 2–3 hrs post-meal, before sleep — aligns with natural GH secretion pulse.
4. Storage
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
Lyophilised: room temp, light-protected. Reconstituted: refrigerate 2–8 °C, use within 21 days.
5. Needle
29–31G, 4–8 mm insulin syringe.
27–31G, 4–8 mm insulin syringe. Pinch skin, 45° angle for lean individuals.
06Stack Synergy
Sermorelin
+ Ipamorelin
StrongSermorelin (GHRH analogue) and ipamorelin (selective GHRP) form the prototypical GHRH+GHRP dual-axis stack at the lowest cost. Both peak within 30 min and produce a sharp physiological GH pulse without cortisol/prolactin elevation.
- Sermorelin
- 200–300 mcg SQ · pre-sleep
- Ipamorelin
- 200–300 mcg SQ · same injection
- Primary benefit
- Pulsatile GH stimulation, recovery, body composition
Tesamorelin
+ Ipamorelin
StrongTesamorelin (GHRH analogue) and ipamorelin (GHRP / ghrelin mimetic) act on two distinct receptor systems to amplify GH release synergistically — GHRH receptor + ghrelin receptor. This dual-axis stimulation produces a more robust, sustained GH pulse than either alone while maintaining physiological pulsatility. Ipamorelin is highly selective with minimal cortisol or prolactin elevation, making it the preferred GHRP pairing.
- Tesamorelin
- 2 mg SQ · evening
- Ipamorelin
- 200–300 mcg SQ · same injection
- Frequency
- Once daily, pre-sleep
- Primary benefit
- Maximal GH pulsatility, fat loss, recovery, sleep quality