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Specimen Atlas of Research Peptides30 plates · MIT
PeptidesDBan atlas
Side-by-side · Research reference

SermorelinvsTirzepatide

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-ApprovedVerified14/45 cited
Sermorelin
GHRH 1-29 fragment · Short-acting
100–500 mcgPer doseMolteno 2013
Phase 3Evidence levelWalker 1994Molteno 2013
~12 minHalf-lifeMolteno 2013
SQ · Pre-sleep · 1×/day
Tirzepatide
GIP+GLP-1 Dual Agonist · FDA-Approved
2.5–15 mgWeekly doseZEPBOUND (tirzepatide) injecti 2023
20.9%Body-weight ↓Jastreboff 2022
~5 daysHalf-lifeZEPBOUND (tirzepatide) injecti 2023
SQ · Abdomen / thigh / arm · Once weekly

01Mechanism of Action

Parameter
Sermorelin
Tirzepatide
Primary target
Pituitary GHRH receptorWalker 1994
GIP receptor (GIPR) + GLP-1 receptor (GLP-1R)Frias 2018
Pathway
GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994
Dual GIPR/GLP-1R agonism → ↑insulin (glucose-dependent), ↓glucagon, ↓gastric emptying, ↓appetite, ↑energy expenditure (via GIP component)Jastreboff 2022Frias 2018
Downstream effect
Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013
Profound glycemic improvement and weight reduction; cardiometabolic benefitsJastreboff 2022
Feedback intact?
Yes — short pulse preserves feedback
Glucose-dependent insulin release preserves physiological feedback
Origin
Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994
39-AA peptide with C-20 fatty-acid acylation. Single molecule with balanced GIP + GLP-1 affinityFrias 2018
Antibody development
—
—

02Dosage Protocols

Parameter
Sermorelin
Tirzepatide
Standard dose
100–500 mcg per injectionMolteno 2013
—
Frequency
Once daily, pre-sleep
—
Lower / starter dose
100 mcg per dose
—
Evidence basis
Phase 3 (Geref pediatric); clinical practiceWalker 1994Molteno 2013
FDA-approved · Phase 3 RCTs (SURMOUNT, SURPASS)Jastreboff 2022ZEPBOUND (tirzepatide) injecti 2023
Duration
8–12 weeks per cycle
Indefinite for chronic indication
Reconstitution
Bacteriostatic water
Pre-filled commercial pen. Research vial: bacteriostatic water per label.
Timing
Pre-sleep, fasted preferred
Once weekly, any time of day
Half-life
~12 min (plasma)Molteno 2013
Shorter than tesamorelin (~26 min) — simpler GHRH analogue.
~5 days (116 h)ZEPBOUND (tirzepatide) injecti 2023
Standard dose (T2D)
—
5–15 mg / weekZEPBOUND (tirzepatide) injecti 2023
Standard dose (weight)
—
5, 10, or 15 mg / week (titrated)ZEPBOUND (tirzepatide) injecti 2023Jastreboff 2022
Titration schedule
—
2.5 mg → +2.5 mg every 4 weeks → 15 mg max
Slower titration mitigates GI side effects.

04Side Effects & Safety

Parameter
Sermorelin
Tirzepatide
Injection site reaction
Mild erythema, transient pain
Mild erythema, pruritus
Flushing / headache
Common transient effect
—
IGF-1 elevation
Modest at standard doses
—
Cancer risk
Contraindicated in active malignancy (GH/IGF-1 axis)
—
Pregnancy / OB
Avoid
Contraindicated
Glucose handling
Generally neutral
—
GI symptoms
—
Nausea, vomiting, diarrhea (common, dose-dependent)Jastreboff 2022
Pancreatitis risk
—
Rare; discontinue if suspectedZEPBOUND (tirzepatide) injecti 2023
Thyroid C-cell tumours
—
Boxed warning — contraindicated in MEN2 / MTC historyZEPBOUND (tirzepatide) injecti 2023
Hypoglycemia
—
Low as monotherapy; risk with sulfonylureas / insulin
Gallbladder events
—
Increased cholelithiasis
Diabetic retinopathy
—
Rapid glycemic improvement may transiently worsen
Absolute Contraindications
Sermorelin
  • ·Active malignancy
  • ·Pregnancy / breastfeeding
  • ·Disrupted hypothalamic-pituitary axis
Tirzepatide
  • ·MTC personal or family history; MEN2
  • ·Pregnancy / breastfeeding
  • ·Hypersensitivity to tirzepatide
Relative Contraindications
Sermorelin
  • ·Untreated diabetes
Tirzepatide
  • ·Severe gastroparesis
  • ·History of pancreatitis
  • ·Diabetic retinopathy

05Administration Protocol

Parameter
Sermorelin
Tirzepatide
1. Reconstitution
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.
Commercial: pre-filled pen / vial. Research lyophilised: bacteriostatic water per label.
2. Injection site
SQ — abdomen or thigh. Rotate sites.
SQ — abdomen, thigh, or upper arm. Rotate weekly.
3. Timing
Pre-sleep, fasted.
Once weekly, same day. Day change allowed if ≥3 days separate doses.
4. Storage
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
Refrigerate 2–8 °C unopened. Room temp ≤30 °C up to 21 days after first use.
5. Needle
29–31G, 4–8 mm insulin syringe.
Pen-supplied. Research vial: 27–31G insulin syringe.

06Stack Synergy

Sermorelin
+ Ipamorelin
Strong
View Ipamorelin →

Sermorelin (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
Raun 1998Walker 1994
Tirzepatide
— no documented stacks