Educational use only. This tool and content are for general information and do not constitute medical advice, diagnosis, or treatment. Peptides and GLP-1 medications should only be used under the supervision of a licensed healthcare provider. Always confirm dosing with your prescriber and the product label. Some peptides discussed are not approved by the FDA for human use.
How the schedule works
Trials began at a low weekly dose and increased it in steps, typically every four weeks, to limit nausea. The lowest doses are “on-ramp” doses meant to build tolerance rather than drive maximum results.
| Stage | Weekly dose | Typical timing |
|---|---|---|
| Start | 2 mg | ~4 weeks |
| Step up | 4 mg | ~4 weeks |
| Step up | 8 mg | ~4 weeks |
| Studied max | 12 mg | Maintenance in trials |
To convert any of these weekly doses into exact units for your vial, use the retatrutide dosage calculator.
Important: retatrutide is not FDA-approved
Retatrutide is still in Phase 3 trials and cannot be legally prescribed or sold as a finished drug in the U.S. If you want a clinician-supervised, FDA-approved GLP-1 for weight loss today, a licensed telehealth provider can assess whether semaglutide or tirzepatide is right for you.
See FDA-approved options →Find a retatrutide trialSome links are affiliate links — we may earn a commission at no cost to you. This is not medical advice.
Frequently asked questions
How often is retatrutide injected?
In trials it was a once-weekly injection.
How fast should retatrutide be increased?
Trials stepped up roughly every four weeks. Slower is safer for tolerability; there is no official outpatient schedule because the drug isn’t approved.
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