Last reviewed: May 2026 · By Noki Labs Team
Educational content only. Always consult a licensed healthcare provider before starting any peptide or wellness protocol.
TL;DR
GLP-1 (glucagon-like peptide-1) is a gut hormone that controls appetite and blood sugar. Modern weight-management peptides mimic GLP-1, sometimes also activating GIP, glucagon, or amylin receptors. Tirzepatide (dual GIP/GLP-1) and Retatrutide (triple GIP/GLP-1/glucagon) are the two leading molecules in 2026; Cagrilintide (amylin analog) is often stacked alongside them for additive effect.
What is GLP-1, and why does it matter?
Your gut releases GLP-1 after meals. It does three useful things:
- Slows gastric emptying — you stay full longer.
- Reduces appetite signaling — hunger volume turns down.
- Improves insulin response — blood sugar regulation gets steadier.
Native GLP-1 has a half-life of about 2 minutes — way too short to be a drug. Modern peptide therapeutics solve this with structural modifications (fatty acid side chains, amino acid substitutions) that extend half-life to days.
For deeper biology, see PubMed: 30224347 (GLP-1 mechanism review).
The four receptor systems in play
| Receptor | Effect | Peptides that target it |
|---|---|---|
| GLP-1 | Appetite ↓, gastric emptying ↓, insulin ↑ | Tirzepatide, Retatrutide, Semaglutide-class |
| GIP | Potentiates GLP-1, may reduce nausea, lipolytic in fat tissue | Tirzepatide, Retatrutide |
| Glucagon | Energy expenditure ↑, lipolysis ↑ | Retatrutide |
| Amylin | Slows gastric emptying further, satiety ↑ | Cagrilintide |
The three molecules in detail
Tirzepatide — the dual agonist
Activates GLP-1 and GIP receptors. SURMOUNT-1, a 72-week Phase-3 trial in adults with obesity, showed mean weight loss of 22.5% at 15mg weekly (placebo: 2.4%). NEJM, 2022. PubMed: 35658024.
Why dual agonism wins: GIP activation seems to enhance GLP-1's appetite suppression while reducing GI side effects. Net result is more weight loss with better tolerability than pure GLP-1 agonists.
Retatrutide — the triple agonist
Adds glucagon receptor activation to the GIP/GLP-1 dual mechanism. Glucagon agonism boosts energy expenditure (your body burns more) and lipolysis (more fat is mobilized). Phase-2 trial: 24.2% weight loss at 12mg over 48 weeks. NEJM, 2023. PubMed: 37366315.
Phase-3 (TRIUMPH program) is in progress. Watch for full readouts in late 2026 / 2027.
Cagrilintide — the amylin analog
Amylin is co-secreted with insulin and reinforces satiety signaling. Cagrilintide is a long-acting amylin analog. On its own, it produces moderate weight loss (~10–11%); stacked with a GLP-1 (e.g., Tirzepatide), it produces additive effects.
The combination is described in PubMed: 34529960 (Cagrilintide Phase-2). Stacking protocol details: our 2026 stack guide.
How to choose
- You want maximum published evidence and easier titration: Tirzepatide. See our Tirzepatide.
- You want the steepest weight-loss curve and accept investigational status: Retatrutide. See our Retatrutide.
- You want to amplify a GLP-1 stack with stronger appetite control: Cagrilintide added to either above. See our Cagrilintide.
Full comparison: Tirzepatide vs Retatrutide and Tirzepatide vs Retatrutide pillar page.
What about side effects?
All GLP-1-class peptides share a similar GI profile during titration: nausea, occasional vomiting, diarrhea, constipation. These are dose-dependent and almost always resolve within 8–12 weeks. We cover management strategies in Tirzepatide side effects.
Glucagon agonists (Retatrutide) add a transient resting heart-rate increase (~3–7 bpm) and can raise fasting glucose at higher doses.
Amylin analogs (Cagrilintide) add minor injection-site reactions and occasional early-morning nausea.
Dosing principles
All three molecules use slow up-titration over weeks to acclimate the body and limit GI symptoms. Typical schedules:
- Tirzepatide: 2.5 → 5 → 7.5 → 10 → 12.5 → 15mg, +4 weeks each step.
- Retatrutide: 2 → 4 → 8 → 12mg, +4 weeks each step.
- Cagrilintide: 0.16 → 0.30 → 0.60 → 1.2 → 2.4mg, +4 weeks each step.
Full dosing reference: Tirzepatide dosage guide.
How this applies in the Philippines
Reference Filipino market pricing (May 2026):
- Tirzepatide: ₱2,000–3,500 across 4 variants.
- Retatrutide: ₱2,500–3,200 across 2 variants.
- Cagrilintide 10mg: ₱2,200.
COD via J&T or LBC, Metro Manila next-day. Use WELCOME10 on first order. Manila peptide supplier hub.
Legality: Premium peptides are legally importable for personal wellness use. Full legal breakdown.
FAQ
Is GLP-1 the same as Ozempic?
Ozempic is a brand of finished GLP-1 drug product (Semaglutide). Tirzepatide and Retatrutide are different molecules with broader receptor activity.
Which works fastest?
Appetite suppression usually appears within 1–2 weeks of starting any GLP-1-class peptide. Visible weight change typically begins by week 4–6.
Can I stack all three?
Tirzepatide + Cagrilintide is a published stack. Adding Retatrutide on top is unproven and not recommended — you'd have receptor overlap and amplified side effects.
Will I regain weight after stopping?
Trials show that stopping GLP-1-class peptides without lifestyle changes typically results in regaining about two-thirds of the lost weight within a year. Sustainable habit change matters.
Are these safe long-term?
Tirzepatide has multi-year safety data. Retatrutide is still investigational. Cagrilintide has 2+ years of trial follow-up data. Discuss with your Philippine clinician.
Where to buy lab-tested peptides in the Philippines
Noki Labs offers HPLC-verified Tirzepatide, Retatrutide, and Cagrilintide. Browse the full weight-management collection, see our Tirzepatide pillar, or read the Tirzepatide vs Retatrutide comparison. Manila buyers: Manila supplier guide.
Always consult a licensed healthcare provider before starting any new peptide or wellness regimen. Individual results vary. Statements about our products are educational and not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed: May 2026 · Read more in our FAQ
