Question 1

What does a GLP-1 dose actually refer to?

Accepted Answer

It refers to a molecule, never to the class. Ask for a GLP-1 dose and the honest reply is a question back: which molecule, and for which approved use? A 2025 review of real-world evidence works from three approved weight-loss members of this class, naming liraglutide, semaglutide and tirzepatide. The family is wider than those three. A 2019 meta-analysis of heart-outcome trials pooled seven molecules under the one name, among them lixisenatide, exenatide, albiglutide and dulaglutide. Each arrived with a schedule of its own, and that analysis notes they differ in their structure and duration of action. So a number with no molecule attached is not an amount at all. It has lost the only thing that made it mean something, and our pages for semaglutide, tirzepatide and retatrutide hold the figures that belong to each.

Question 2

Which schedules were used, and at what amounts?

Accepted Answer

Three of them carry almost the whole published record. The first is a weekly injection under the skin. SURPASS-1 randomly assigned adults with type 2 diabetes to once a week tirzepatide (5, 10, or 15 mg), or placebo. The second is a daily injection, which is where the older molecules sit. A one-year Copenhagen trial ran the GLP-1 RA liraglutide 3.0 mg/day in adults with obesity, against arms of exercise and of placebo. The third is a tablet swallowed every day. A 2019 phase 3a trial randomised adults with type 2 diabetes to once-daily oral semaglutide 3 mg, 7 mg, 14 mg, or placebo. A 2025 phase 3 trial in obesity used once-daily orforglipron at doses of 6 mg, 12 mg, or 36 mg over 72 weeks. Each of those lines fixes a route, an amount and an interval together, and all three were settled before anybody was enrolled.

Question 3

Can one dosing chart cover the whole class?

Accepted Answer

Not without inventing rungs, because the ladders underneath are not interchangeable. A 2024 network meta-analysis defined its inclusion rule by maintenance amount, admitting s.c. tirzepatide at maintenance doses of 5 mg, 10 mg or 15 mg once weekly, or s.c. semaglutide at maintenance doses of 0.5 mg, 1.0 mg or 2.0 mg once weekly. The abbreviation s.c. stands for subcutaneous, meaning an injection into the layer of fat beneath the skin. Set those two ladders alongside each other and they fail to correspond at any point, although both molecules were administered weekly to comparable patients with type 2 diabetes. The highest maintenance amount recorded for one of them is considerably smaller than the lowest amount recorded for the other. A chart headed GLP-1 would therefore have to print rungs that do not correspond and leave a reader assuming that they do. What remains usable is a chart belonging to one molecule and one approved indication, which is what our individual compound pages carry, rather than a class-wide ladder that nothing in this record supplies.

Question 4

Why do the published protocols start below their target?

Accepted Answer

Because the gut sets the pace. A 2020 review of this class names the constraint plainly, reporting that dose-related gastrointestinal effects limit efficacy. Gastrointestinal means the stomach and the bowel, and dose-related means the difficulty grows as the amount grows. The trials answer that by escalating gradually. A 2023 tablet trial reports that its gastrointestinal events, which were mild to moderate, occurred primarily during dose escalation. Escalation describes the run of weeks spent stepping upward before an assigned amount is maintained. Read what that interval is actually for. It is a method of reaching a randomly assigned amount without losing the participant on the way there, administered by a clinic holding material of known identity and strength. It is a trial protocol rather than a schedule handed to somebody holding an unlabelled vial, and the distance between those two things is most of what this page concerns.

Question 5

Why is one of these weekly and another daily?

Accepted Answer

Because the interval belongs to the molecule rather than to the prescriber. A 2019 meta-analysis of heart-outcome trials grouped its evidence by trial duration, treatment dosing interval, and structural homology. Structural homology means how closely an engineered molecule resembles the natural hormone. One peptide family holds both ends of the range. A 2024 trial gave a subcutaneous injection of either semaglutide 2·4 mg or placebo once a week for 44 weeks, while a Copenhagen trial used 3.0 mg daily of the GLP-1 RA liraglutide for a year. Two injected peptides acting on one receptor, and one of them goes in seven times as often. A 2022 review of newer diabetes medicines reads the same fact forward. It notes that once-weekly administrations of incretin mimetics open up the potential of a combination with once-weekly insulins. Incretin mimetics are copies of the gut hormones this class imitates, and the lesson for a reader is plain enough: change the name on the box and the schedule changes with it.

Question 6

Why do the amounts differ so much between molecules?

Accepted Answer

Because they are not all performing the same job at the same receptor. A 2025 comparative review states the split in a single line: Semaglutide is a GLP-1 receptor agonist, while Tirzepatide acts as a dual agonist for the GLP-1 and GIP receptors. GIP is the other gut hormone around which this class is built. The engineering behind that arrangement is older than either molecule's approval. A 2020 review describes how GLP-1 activity can be built into the sequence of GIP, which is a way of making a single molecule answer to two different hormones simultaneously. So milligrams are not a shared currency across this class. Two vials can carry an identical figure and contain two molecules performing different work at different receptors, which is why an amount quoted without a molecule name attached is not information that a reader can use. A chart stacking those figures in one column is stacking units that were never comparable units.

Question 7

What does microdosing a GLP-1 mean?

Accepted Answer

It is a term from the marketplace rather than from the literature, and no trial among the research behind this page employs it. What the published work does record is that people outside trials administer considerably less than the trials assigned. A 2025 review of real-world evidence reports high discontinuation rates of GLP-1RAs (20%-50%) within the first year, and the use of much lower doses than those evaluated in clinical trials. That is a description of behaviour rather than a protocol anybody tested. The same review asks for better understanding of what drives early discontinuation and suboptimal dosing, which is a request for further research rather than an answer to one. So the term covers a genuine phenomenon without describing a measured one. An amount beneath what a trial assigned represents a different exposure from the one every published figure emerged from, and whether it accomplishes anything at that size is a question these investigations were never designed to ask.

Question 8

Is a smaller amount still a studied amount?

Accepted Answer

Sometimes, and the smaller published arms are worth knowing about. A 2021 analysis of a diabetes programme lists its arms as Tirzepatide (1, 5, 10, 15 mg), dulaglutide (1.5 mg), placebo, in three hundred and sixteen subjects with type 2 diabetes. One milligram sits considerably below the amounts that subsequently carried an approval. The tablet record contains a wide span of its own. A 2023 phase 2 trial assigned adults with obesity to orforglipron at one of four doses (12, 24, 36, or 45 mg) or placebo once daily for 36 weeks, approaching a fourfold range inside a single molecule. Those are randomly assigned arms rather than a licence for arithmetic. Each sat inside one investigation, in one population, with material of known identity, and each generated a result belonging to that arm alone. A small number written into a protocol and a small number drawn from an unlabelled vial are different objects rather than one object encountered twice.

Question 9

Are these amounts scaled to body weight?

Accepted Answer

No protocol among the research behind this page sets an amount per kilogram of body weight. Every arm quoted here is a fixed figure in milligrams, given to everyone assigned to it. A 2025 paediatric trial is typical, in that participants were randomly assigned to tirzepatide 5 mg (n=32), tirzepatide 10 mg (n=33), or placebo (n=34), with no adjustment for how big anybody was. That design has a consequence most charts hide. Two people of very different size inside one arm received exactly the same amount, so a per-kilogram figure cannot be recovered from these results at any point. It also means this page will not produce one. A conversion from a fixed trial amount onto a reader's own body is arithmetic that nothing in this record validates, and publishing it would be a dosing instruction wearing a decimal point rather than a finding about this class.

Question 10

How soon after starting was weight measured?

Accepted Answer

Later than anybody searching for a three-month number would expect. No trial among the research behind this page reports a weight figure at three months. The earliest endpoint anywhere in it is week 26, in a 2023 phase 2 trial where the percentage change from baseline in body weight was assessed at week 26 (primary end point) and at week 36 (secondary end point). The remaining trials sit further out again. A 2025 phase 3 obesity trial ran its assignment as an adjunct to healthy diet and physical activity for 72 weeks, and a 2025 diabetes trial of the same tablet maintained its arms for 40 weeks. Month three is therefore a gap in the evidence rather than a small number waiting to be quoted. Every published figure describes participants who had spent weeks escalating and then months maintaining an assigned amount, which is a different question rather than the same question asked earlier. A trial average was never a forecast for any individual reader's calendar in any case.

Question 11

How much protein should you eat while taking one?

Accepted Answer

No published figure answers that, and the review that went looking explains why. A 2024 narrative review of what people eat on these medicines found that few studies evaluated the actual composition of the diet. The most practical daily question in this class is among the least measured. What was measured is how much less went in. The same review reports that total caloric intake was reduced by 16-39 % among the patients studied, which is a substantial shift in quantity with almost no record of what the food consisted of. Why that matters sits in the body-composition literature. A 2025 network meta-analysis of randomised trials reports lean mass loss comprising approximately 25 % of the total weight loss in those participants, and lean mass is everything that is not fat. Protein is the obvious lever a reader would reach for, and the honest position is that its effect alongside these medicines has not been measured rather than that it accomplishes nothing.

Question 12

What does an approved schedule not cover?

Accepted Answer

One molecule, one approved use and one labelled product, and nothing at all beyond those three. Several molecules in this class hold no approval whatever. A 2025 phase 3 report describes orforglipron as a small-molecule, nonpeptide oral glucagon-like peptide-1 (GLP-1) receptor agonist, and a second 2025 report places the same tablet in clinical development for type 2 diabetes and weight management. In clinical development is not a synonym for approved. A 2025 review keeps its own approved list to liraglutide, semaglutide and tirzepatide, and an approval granted for blood sugar is a separate decision from an approval granted for weight. Nothing on this page has been established as applying to a compounded or research-grade vial. Those carry no approved label, so every amount above belongs to the material the trials used and to the products a regulator licensed, rather than to whatever is inside an unlabelled container. The test is a simple one. If a figure cannot be traced to a named molecule, a named trial or a named approval, it is not a figure about this class.

Trial	Molecule	Route and interval	Amounts studied
SURPASS-1	Tirzepatide	Injection, once a week	5, 10 or 15 mg
Copenhagen trial	Liraglutide	Injection, daily, for one year	3.0 mg/day
2019 phase 3a trial	Oral semaglutide	Tablet, once daily	3, 7 or 14 mg
2025 phase 3 trial	Orforglipron	Tablet, once daily, 72 weeks	6, 12 or 36 mg

GLP-1 protocols in the published literature