Comparison
Ipamorelin vs Tirzepatide
Side-by-side of Ipamorelin and Tirzepatide. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Ipamorelin
Ipamorelin peptide benefits: selective ghrelin-receptor GHRP, 200 to 300 mcg dosage, GH pulse without cortisol or prolactin rise, CJC-1295 stack vs sermorelin.
Tirzepatide
Tirzepatide for weight loss: dual GIP/GLP-1 agonist sold as Mounjaro and Zepbound. SURMOUNT-1 showed 22.5% mean body-weight loss at 15 mg over 72 weeks.
Effects at a glance
Ipamorelin
- •Pentapeptide GHS-R1a agonist with the cleanest selectivity profile in the GHRP class
- •Minimal cortisol and prolactin elevation at standard doses (substantially less than GHRP-2 or hexarelin)
- •~2 hour plasma half-life, longest of the synthetic GHRPs
- •Largest human safety database (~600 participants in Helsinn's postoperative ileus phase 2)
- •Standard pairing for CJC-1295 no-DAC at 200 to 300 mcg subcutaneously 2 to 3 times daily
- •Banned by WADA under S2; never reached registration despite phase 2b development
Tirzepatide
- •Dual GIP plus GLP-1 receptor agonist with a ~5-day half-life supporting once-weekly subcutaneous dosing
- •SURMOUNT-1 reported ~22.5% mean body-weight loss at 15 mg over 72 weeks versus 2.4% on placebo
- •Lowers HbA1c by ~1.9 to 2.6 percentage points in type 2 diabetes across SURPASS trials
- •Outperformed semaglutide 1.0 mg head-to-head on weight loss and HbA1c in SURPASS-2
- •GI effects (nausea, diarrhea, vomiting) drive most discontinuations and ease with slow titration
- •Lean-mass loss observed in body-composition substudies; resistance training and protein intake mitigate this
Side-by-side
| Attribute | Ipamorelin | Tirzepatide |
|---|---|---|
| Category | peptide | pharmaceutical |
| Also known as | NNC 26-0161, Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Mounjaro, Zepbound, LY3298176 |
| Half-life (hr) ↗ | 2 | 120 |
| Typical dose (mg) ↗ | 0.2 | 10 |
| Dosing frequency | 2-3x daily | weekly |
| Routes | subcutaneous, intravenous | subcutaneous |
| Onset (hr) | 0.25 | 24 |
| Peak (hr) | 1 | 72 |
| Molecular weight | 711.86 | 4813.45 |
| Molecular formula | C38H49N9O5 | C225H348N48O68 |
| Mechanism | Selective GHS-R1a agonist that stimulates pulsatile GH release with minimal cortisol or prolactin co-activation. Suppresses hypothalamic somatostatin and stimulates pituitary somatotrophs. | Synthetic 39-amino-acid peptide that activates both GIP and GLP-1 receptors. Potentiates glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic and brainstem satiety circuits. |
| Legal status | Not FDA approved; advanced through phase 2b in postoperative ileus before discontinuation; research-use-only grey market; banned by WADA | Prescription only; FDA-approved 2022 (T2DM, Mounjaro) and 2023 (chronic weight management, Zepbound) |
| WADA status | banned | allowed |
| DEA / Rx | Not scheduled (research chemical) | Rx only (not a controlled substance) |
| Pregnancy | Insufficient data; not recommended | Not recommended; discontinue 2 months before planned pregnancy |
| CAS | 170851-70-4 | 2023788-19-2 |
| PubChem CID | 11338566 | 156588324 |
| Wikidata | Q1666741 | Q105099794 |
Safety profile
Ipamorelin
Common side effects
- injection-site irritation
- vivid dreams
- transient mild head pressure
- occasional headache
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
Interactions
- CJC-1295: synergistic GH release via parallel GHRH and ghrelin pathways; standard pairing(minor)
- sermorelin: additive GH release; functionally similar pairing to CJC-1295 with shorter GHRH half-life(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response; reduce expected efficacy(moderate)
Tirzepatide
Common side effects
- nausea
- diarrhea
- vomiting
- constipation
- decreased appetite
- injection-site reactions
- fatigue
- abdominal pain
Contraindications
- personal or family history of medullary thyroid carcinoma
- multiple endocrine neoplasia type 2
- pregnancy
- history of pancreatitis (use caution)
- severe gastroparesis
Interactions
- insulin: additive hypoglycemia risk; insulin dose typically reduced(major)
- sulfonylureas (glipizide, glyburide): hypoglycemia risk, sulfonylurea dose often reduced(major)
- oral medications (general): delayed gastric emptying can alter absorption kinetics(moderate)
- oral contraceptives: reduced exposure after first dose; backup contraception recommended for 4 weeks after initiation and each dose escalation(moderate)
- warfarin: monitor INR due to altered absorption(moderate)
Which Should You Take?
Tirzepatide comes out ahead for most readers on the criteria we weight: 3 catalogued goals, prescription-only, with a Tier-A outcome catalogued. Ipamorelin is the right call when one of the conditionals below applies.
- → If your priority is growth-hormone axis, pick Ipamorelin.
- → If your priority is post-training recovery, pick Ipamorelin.
- → If your priority is metabolic health and glucose control, pick Tirzepatide.
- → If your priority is fat loss, pick Tirzepatide.
Edge case: Half-lives differ materially (Ipamorelin ~2 hr vs Tirzepatide ~120 hr). Tirzepatide reaches steady state faster; Ipamorelin is easier to dial in if tolerability is uncertain.
Default choice: Tirzepatide. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Ipamorelin only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Ipamorelin and Tirzepatide?
Ipamorelin and Tirzepatide differ in category (peptide vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Ipamorelin or Tirzepatide?
Ipamorelin half-life is 2 hours; Tirzepatide half-life is 120 hours.
Can you stack Ipamorelin with Tirzepatide?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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