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GLP-1 / GIP / glucagon agonist

Retatrutide

Also known as Triple-G

The next-gen triple agonist posting the biggest trial weight-loss numbers yet.

Emerging evidence

Overview

Retatrutide - sometimes called Triple-G - is a next-generation weight-loss compound that targets three receptors at once: GLP-1, GIP, and glucagon. By activating all three simultaneously, it aims to produce more powerful fat loss than current dual-agonist options. Early clinical trials have reported some of the largest weight-loss percentages seen yet in a pharmaceutical agent, which is why there is significant interest in it. The triple mechanism works by combining the appetite suppression of GLP-1, the metabolic enhancement of GIP, and the fat-burning and energy-expenditure effects of glucagon receptor activation. Together, these create a broad metabolic signal aimed at maximal fat reduction. Retatrutide is currently investigational - it has not yet received FDA approval. This means it is accessed only in supervised, monitored protocols and is not widely available. Evidence is categorized as emerging, based on clinical trial data that is still accumulating. It is given as a once-weekly subcutaneous injection, on the same day each week. Dose range in trials has been 1 to 12 mg, with careful titration to manage tolerability. GI side effects comparable to other GLP-1-class agents are expected during titration. Retatrutide should not be combined with other agents in this class - not semaglutide, tirzepatide, or liraglutide. It is not appropriate during pregnancy. Because human safety data is still developing, protocols are closely supervised. No compatible stacking partners are listed for retatrutide - it is generally used as a standalone agent. Exact dosing, titration, and monitoring schedule are set with a licensed provider in the PepDepo network at your consult.

At a glance

Route
SC injection
Dose
1-12 mg
Frequency
Once weekly
Timing
Same day each week
Cycle
Investigational; supervised

Combining

Avoid combining with: Semaglutide, Tirzepatide

Safety

Still in trials; GI side effects expected.

Regulatory: Investigational, not yet FDA-approved.

Not appropriate if: pregnant.

Questions

How is retatrutide different from tirzepatide or semaglutide?

Retatrutide hits three receptors - GLP-1, GIP, and glucagon - where tirzepatide hits two and semaglutide hits one. Adding the glucagon receptor adds energy-expenditure effects on top of appetite suppression, which is what produces the larger weight-loss numbers seen in early trials.

Is it FDA-approved?

No. Retatrutide is investigational and has not yet received FDA approval. It is accessed only through supervised clinical protocols.

How is it taken?

Once-weekly subcutaneous injection on the same day each week. Doses in trials have ranged from 1 to 12 mg, titrated up based on tolerability.

What side effects should I expect?

GI side effects - nausea and related symptoms - are expected during titration, consistent with what is seen with other GLP-1-class agents. Because human safety data is still being collected, all protocols are closely monitored.

Who should not use retatrutide?

People who are pregnant should not use it. As with all GLP-1-class agents, those with a personal or family history of medullary thyroid cancer should discuss this with their clinician before considering it.

Can I stack it with other peptides?

Retatrutide cannot be combined with other GLP-1 agonists including semaglutide, tirzepatide, or liraglutide. No additional stacking partners are currently listed for it.

Want a personalized protocol?

Exact dosing is set with a licensed provider in the PepDepo network. This page is education, not a prescription.

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Education only, not medical advice. Peptides discussed are for informational purposes and many are not FDA-approved. Eligibility, prescribing, compounding, and dispensing are handled by appropriately licensed entities. Exact protocols and dosing are set with a licensed provider in the PepDepo network at consult. Content is pending clinical review.