PeptideGLP-1EmergingGLP-1 Agonist

Retatrutide

Triple agonist (GLP-1 / GIP / glucagon)

Typical dose

2–12 mg weekly

once weekly · SubQ · titrate up over 12–24 wks

Half-life

~6 days

What is Retatrutide?

Triple agonist (GLP-1, GIP, glucagon). Most powerful GLP-1 class agent for weight loss.

How Retatrutide works

Simultaneously activates GLP-1, GIP, and glucagon receptors to suppress appetite, accelerate lipolysis, and improve metabolic efficiency — producing greater weight loss than dual or single agonists.

Benefits & uses

Weight loss
Appetite suppression
Metabolic health
Blood glucose control
Largest weight loss of any obesity agent to date (~24–29% in trials)
Powerful appetite reduction
Improves insulin sensitivity (GIP)
Boosts energy expenditure / fat burning (glucagon)
Metabolic + fatty-liver benefit

Common uses: Weight loss, appetite suppression, metabolic health, blood glucose control.

Retatrutide dosage

Typical dose: Typical: start 2 mg/week SubQ, titrate every 4 weeks (2→4→8→12 mg/week). Most run 12–24 week blocks, once weekly, same day.
Protocol notes: Starting: 2 mg/week SubQ. Titrate every 4 weeks up to 12 mg/week. Inject once weekly, same day each week.

Retatrutide half-life

~6 days (allows once-weekly dosing)

Retatrutide side effects

Nausea, vomiting, constipation, injection site reactions. Gallbladder concerns with rapid weight loss.

Nausea (most common, especially during titration)
Vomiting and diarrhea
Constipation
Injection site reactions
Gallstones with rapid weight loss
Not yet FDA-approved (Phase 3 trials)
Nausea
Vomiting
Diarrhea
Fatigue
Headache
Mild heart-rate increase

Warnings & monitoring

Research use only
Nausea, vomiting, constipation
Gallbladder concerns with rapid weight loss
Not yet FDA-approved (Phase 3 trials)
Titrate slowly — GI effects are worst when starting or raising the dose
Class risks (GLP-1): rare pancreatitis, gallbladder disease, gastroparesis
Thyroid C-cell tumor class risk (rodent data) — avoid with personal/family history of medullary thyroid cancer or MEN2
Not for pregnancy
Glucagon component can raise heart rate — monitor

Preparation & storage

Preparation: Mix a 10 mg vial with 2 mL bac water → 5 mg/mL. A 2 mg dose = 0.4 mL = 40 units. Start at 2 mg/week, titrate every 4 wks (2→4→8→12).
Reconstitution: Reconstitute a 10 mg vial with 2 mL BAC water → 5 mg/mL. A 2 mg dose = 0.4 mL = 40 units on a U-100 syringe.
Storage: Refrigerate (2–8 °C). Once in use, can be stored at room temp (up to 30 °C) for 4 weeks. Keep away from light.

Retatrutide interactions

with Semaglutide
Avoid · severe
Both are GLP-1 receptor agonists; combining them dramatically increases nausea, vomiting, and gastrointestinal distress with no meaningful additive benefit.
Timing: Do not use concurrently under any circumstances
with Tirzepatide
Avoid · severe
Tirzepatide (GLP-1/GIP dual) and Retatrutide (GLP-1/GIP/glucagon triple) share two overlapping receptor targets — concurrent use significantly amplifies adverse effects.
Timing: Do not use concurrently
with BPC-157
Compatible
BPC-157's gut-healing properties counteract the nausea, gastroparesis, and gastritis often seen with high-dose Retatrutide titration.
Timing: BPC-157 daily to mitigate GLP-1 GI side effects

Commonly stacked with

AOD-9604 BPC-157 KLOW GLOW

Track Retatrutide in Protokol.

Log doses, model half-lives, check interactions, and line it all up against your bloodwork. Free on iPhone and Android.