Tirzepatide vs Retatrutide
There is no winner on this page. What is set side by side is the published record behind each one, which is the part the two are rarely compared on.
Both in Metabolic and GLP-1
One is approved and the other is approved nowhere, which changes what a vial can be held against rather than what is in it. Retatrutide's circulating figures did not come out of its trials: those used 1, 4, 8 and 12 mg a week, while 10 mg is one standard vial and 20 mg is two, and 20 mg is two thirds again the highest dose ever given to anyone in a published trial. With no approved version at any price there is no reference article to hold a vial against, which is not a problem tirzepatide has.
| Field | Tirzepatide | Retatrutide |
|---|---|---|
| What a trial gave | 5, 10 and 15 mg weeklySURMOUNT-1, about a fifth of body weight at the top dose | Up to 12 mg weeklyLilly phase 2, about a quarter of body weight at the top dose |
| What circulates | Microdoses below 2.5 mg weekly | 0.25 to 1.5 mg starting, 4 mg maintenance |
| The gap | Below the studied dose | Below the studied dose |
| How long it lasts | The entry gives no number for how long it lasts in the body. It says only that a fatty tail on the molecule stretches its stay far enough for one injection a week under the skin, which is how every human trial dosed it. | About 6 days, from the published human trial work on the shot given under the skin. That is why the dosing is weekly. |
| Route studied | Under the skin, once a week, in large trials | Under the skin, once a week, in company trials |
| Route used | Under the skin at home, once a week. Pharmacy mixed versions have also been sold as under the tongue liquids and dissolving tablets, neither an approved way to take it. | Under the skin, once a week, from unapproved vials |
| Vial sizes | 5, 10, 15, 20, 40, 60 mg | 10, 12, 24, 30, 60 mg |
The distance, stated
Below the studied dose
Tirzepatide
Microdosing was tested once. At the smallest dose people lost under a kilogram in six months.
Below the studied dose
Retatrutide
Trial results describe a molecule, not a vial. No approved version exists at any price, so there is no reference article to hold yours against.
What people get wrong
Tirzepatide
The mistake that costs money and safety is quoting the trial numbers while buying something the trials never used. The 20.9% figure comes from branded tirzepatide at the top weekly dose over 72 weeks, whereas the only randomised weight result anywhere near the tiny doses sold online was under a kilogram in six months, and roughly a quarter of people on that dose still had stomach and gut side effects.
Retatrutide
People assume the dose numbers passed around online came out of the trials. They came out of vial sizes: the trials used 1, 4, 8 and 12 mg a week, while 10 mg is simply one standard vial and 20 mg is two, and 20 mg is two thirds again the highest dose ever given to anyone in a published trial.
Every figure above is carried across from each compound’s entry, which is where the citations live.
All 65 compounds on one page at what circulates vs what was studied, or pick another two to compare.