CT-388 is a glp-1 / gip agonist used for weight loss. CT-388 is a dual GLP-1 and GIP agonist, the same two-receptor family as tirzepatide. In plain terms: it works on two appetite-and-blood-sugar signals for weight loss. It is a weekly shot still in trials.

How much water do I add to CT-388?

You can reconstitute CT-388 with 0.5, 1, or 2 mL of bacteriostatic water. Each option produces a different concentration and syringe draw for the same dose. Use the calculator to see which is easiest to measure.

What does CT-388 cost per dose?

Cost per dose depends on vial size, price paid, and your dose. Enter your vendor's price in the CT-388 calculator to see cost per dose and monthly cost.

What is the reference dose for CT-388?

The commonly referenced range is 4 up to 24 mg per week (trial doses), taken weekly. This is reference information, not a recommendation. Talk to a licensed clinician.

What are the side effects of CT-388?

Reported side effects of CT-388 include: Stomach side effects.; Trial-only.. Severity and frequency vary by person and dose.

Who should not take CT-388?

CT-388 is generally not appropriate for: No formal contraindications established; Pregnancy. Talk to a licensed clinician before starting.

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Decoding

CT-388_Dosage, benefits & legal status

By the Peptide Decoding Editorial Team

Published July 22, 2026 · Updated August 14, 2026

An experimental weekly weight-loss shot in the tirzepatide family.

Weight lossGLP-1 / GIP agonistInvestigational

InGLP-1 agonists

Dose4 up to 24 mg per week (trial doses)

FrequencyWeekly

RouteUnder the skin (subcutaneous)

StatusInvestigational

MixYour choice, calculate it

CycledNot cycled in the trials

Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.

What is CT-388?

Plain language first. The technical label stays, but it never stands alone.

Overview

It works on two appetite-and-blood-sugar signals for weight loss. It is a weekly shot still in trials.

The technical version

CT-388 is a dual GLP-1 and GIP agonist, the same two-receptor family as tirzepatide.

What it's used for

An experimental weekly weight-loss shot in the same family as tirzepatide. It is in testing.

How does CT-388 work?

What it does in the body, and where.

CT-388 targets GLP-1 and GIP, the same pair as tirzepatide, with a different molecule.

01
Both receptors, once a week
Appetite and blood-sugar signalling through two gut hormones at once.
02
Phase 2 numbers were strong
The topline result at the highest dose was among the larger figures reported in this class.
03
Investigational, and reported mainly by press release
Peer-reviewed publication is thinner than for the approved drugs, so treat the figures as provisional.

Receptors

Hits 2 receptors at once.

What else is it used for?

Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.

Weight lossInvestigational
Type 2 diabetesInvestigational

The published record

Research index

Records indexed for CT-388

10 in humans, 1 of them original studies.

8 registered trials, 0 with posted results.

Browse the records

In animalsPro

In the labPro

ReviewsPro

Senior author sharePro

Counted from Europe PMC indexing, not read by a person. Human means indexed under humans, which includes reviews and work on human cells. Original studies exclude reviews and lab work on human cells.Last updated 12 September 2026.

Compound field notes

At a glance

Four things to know about CT-388

Evidence

Investigational

How much, and do you cycle it?

The range, and whether you take breaks.

4 up to 24 mg per week (trial doses), weekly. Not cycled in the trialsTrial dose

Given continuously for the whole study period: 48 weeks. The dose is stepped up at the start, which is a ramp rather than a cycle, and no trial in this class built in a planned break.

Compare this against the whole library →

How long does it stay in the body?

The half-life, and where the figure comes from.

About 6 daysTrial protocol

Source: Phase 1 NCT04838405. PMC12771327, 2025

You can compare this against the whole library to see where it sits.

How do I dose and price it?

Enter your vial and your dose. Pick a mix. We show the draw and the cost.

The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.

Your vial size (mg)

Printed on the vial.

What you paid per vial

Used for cost per dose only.

Your dose (mg)

Commonly referenced range: 4 up to 24 mg per week (trial doses)Trial dose

Choose your mix

0.5 mL water20units · 20 mg/mL

Half a 100-unit syringe

1 mL water40units · 10 mg/mL

One full 100-unit syringe

Easiest

2 mL water80units · 5 mg/mL

Two full 100-unit syringes

your own mL

units · —

Enter your own volume

Measuring the water1 mL = one full 100-unit syringe.

Your draw

80 / 100 units

Full calculator with reorder date →Read a syringe →

How do you store it?

Before mixing, and after.

Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.

Unmixed lyophilized CT-388 keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.

What are the side effects and cautions?

Known cautions and warnings for this compound.

Handling note

This compound is in clinical trials and is not sold in a standard vial, so there is no common vial size to show. Trial doses are given as prepared by the study, and the reconstitution calculator does not apply. Doses up to 24 mg a week are more than twice the 10 mg reference vial.

Who should avoid it

Check these before anything else.

No formal contraindications established
Pregnancy

Stop and get help

These are emergencies. Seek care.

Vomiting badly enough that you cannot keep fluids down
Severe stomach pain that spreads to your back
Signs of an allergic reaction such as face or throat swelling, hives, or trouble breathing

Common effects

Expected, and usually mild.

Mild to moderate stomach effects, consistent with this drug family
In Phase 2, about 6% stopped because of side effects against 1% on placebo

Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.

Is CT-388 approved?

And where the numbers on this page come from.

No. CT-388 is not approved anywhere and is currently in company-run clinical trials. There is no legal route to obtain it outside a trial.

Approval status
Investigational
Route
Under the skin (subcutaneous)
Checked
September 2026

What has happened recently

We have not yet written a full regulatory note for this compound. The status above is current as of the date shown.

You can compare this against the whole library, or read how to check a seller.

DoseFrom published clinical trials. Not approved by a regulator for this dose.
Vial sizeFrom what vendors typically list; not a recommendation.
Sources
Roche, positive phase 2 results for dual GLP-1/GIP receptor agonist CT-388 in obesity
Reviewed8 September 2026

What else is like CT-388?

Others in GLP-1 agonists, side by side.

If you're weighing CT-388, it's worth reading Pemvidutide, Zovaglutide (ZT-002), and Dulaglutide (Trulicity) in the same class.

YOU ARE HERE

CT-388

An experimental weekly weight-loss shot in the tirzepatide family.

Investigational

Dose: 4 up to 24 mg per week (trial doses)
How often: Weekly

PEMVI

Pemvidutide

An experimental weekly shot for weight loss and fatty liver.

Investigational

Dose: 1.2 up to 2.4 mg per week (trial doses)
How often: Weekly

ZOVA

Zovaglutide (ZT-002)

An experimental once-a-month weight-loss shot.

Investigational

Dose: 80 up to 160 mg per month (trial doses)
How often: Monthly

DULA

Dulaglutide (Trulicity)

A weekly GLP-1 shot for diabetes, with far less weight loss than the famous ones.

FDA-approved

Dose: 0.75 up to 4.5 mg per week (start low, increase slowly)
How often: Weekly

Browse the full GLP-1 lineup

Side by side with every GLP-1 agonist

Guides for this compound

How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
Why Does My Peptide Injection Itch or Welt
Injection-site irritation, a histamine reaction, or a true allergy, and how to tell them apart.
How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.

Sources

Roche, positive phase 2 results for dual GLP-1/GIP receptor agonist CT-388 in obesity(2026)
CT388-103. Placebo-adjusted weight loss of 22.5 percent on the efficacy estimand at 48 weeks at the 24 mg dose, and 18.3 percent on the treatment-regimen estimand. 54 percent of the 24 mg group reached a BMI below 30 against 13 percent on placebo.

Last reviewed 8 September 2026

Beyond these, 10 records are indexed. Browse the records