"Microdosing semaglutide" means amounts below the smallest one on the label, and for this molecule the label floor is 0.25 mg once weekly. What makes semaglutide different from tirzepatide on this question is that its developer did test smaller amounts, in two phase 2 trials that decided which doses went on to phase 3. This page reports what the labels state, what those trials posted, what the published literature on microdosing consists of, and what the smaller amounts are as syringe units in a powder vial. It describes no practice to follow.
The label escalation to 2.4 mg and 7.2 mg is on the semaglutide dosage page; the equivalent page for the other molecule is tirzepatide microdosing, where the record below the label is a single arm. Medibact's Semaglutide guide covers the compound itself.
What the labels state
Both injected products start at the same place. The Ozempic label (DailyMed version published 2026-06-10) sets 0.25 mg once weekly for 4 weeks, then 0.5 mg, with steps to 1 mg and 2 mg. The Wegovy label (published 2026-06-30) sets 0.25 mg for weeks 1 to 4, then 0.5, 1 and 1.7 mg in four-week steps, a usual maintenance dose of 2.4 mg, and a maximum of 7.2 mg once weekly. Neither label describes any amount below 0.25 mg, and no approved injected strength is smaller.
The approved products are solutions of fixed strength. The Ozempic pen that delivers 0.25 mg holds 2 mg in 3 mL (0.68 mg/mL), so its 0.25 mg dose is 0.375 mL; Ozempic single-dose prefilled syringes hold 0.25 mg in 0.5 mL. Neither is built to give a fraction of its dose, and the Ozempic instructions state: "Do not set the dose by counting the number of clicks you hear." The Ozempic pen clicks page sets out why click charts disagree.
The trial arms below 0.25 mg
The obesity dose-finding trial (NCT02453711). Novo Nordisk randomised 957 adults with obesity and without diabetes to semaglutide once DAILY at 0.05, 0.1, 0.2, 0.3 or 0.4 mg, two fast-escalation arms, liraglutide 3.0 mg or placebo, for 52 weeks (published as O'Neil et al., Lancet 2018, PMID 30122305). The posted results on ClinicalTrials.gov (read 2026-09-24):
| Arm (once daily) | Weekly total | Body weight, % change | ≥5% loss | ≥10% loss |
|---|---|---|---|---|
| Placebo | — | -2.29 | 22.9% | 10.1% |
| Semaglutide 0.05 mg | 0.35 mg | -5.99 | 53.5% | 18.9% |
| Semaglutide 0.1 mg | 0.7 mg | -8.62 | 67.5% | 36.6% |
| Semaglutide 0.2 mg | 1.4 mg | -11.60 | 74.9% | 56.0% |
| Semaglutide 0.3 mg | 2.1 mg | -11.17 | 80.5% | 57.8% |
| Semaglutide 0.4 mg | 2.8 mg | -13.84 | 82.5% | 64.6% |
| Liraglutide 3.0 mg | — | -7.76 | 66.1% | 34.0% |
The weekly-total column is this site's arithmetic (daily amount × 7). The lowest arm, 0.35 mg a week in total, is just above the Wegovy starting dose, and it is the only arm in any semaglutide trial found for this page that stayed near that level for a full year.
The diabetes dose-finding trial (NCT00696657). Before it, a 12-week trial in 415 patients with type 2 diabetes gave once-weekly semaglutide at 0.1, 0.2, 0.4 and 0.8 mg without escalation, or escalated to 0.8 or 1.6 mg (Nauck et al., Diabetes Care 2016, PMID 26358288). The abstract reports that HbA1c and weight fell with dose, that nausea and vomiting rose with dose, and that 0.5 and 1.0 mg with a four-week escalation were selected for phase 3. The registry record holds no posted weight results by arm, so this page gives none.
The daily diabetes trial (NCT02461589). A third Novo Nordisk trial, 706 participants with type 2 diabetes over 26 weeks, repeated the once-daily design. Its posted results (read 2026-09-24) give a body-weight change of -2.75 kg on 0.05 mg a day and -4.36 kg on 0.1 mg a day, against -1.22 kg on placebo.
Three limits apply to reading either trial as evidence about microdosing. The obesity trial dosed daily, which gives flatter levels than one weekly injection. Both trials were run with medical follow-up and fixed arms, not as reductions after a higher dose. And the lowest amounts were included to map the dose-response curve, not because they were candidate treatments; phase 3 went higher.
What the published record on microdosing consists of
A PubMed search for microdos*[tiab] AND semaglutide on 2026-09-24 returned four records: two letters in Diabetes Care on smaller amounts from multi-dose pens (PMIDs 39808463 and 40540673), a nurse-practitioner report on the practice's drivers and dosing errors (PMID 42201545), and a narrative review in Cureus (PMID 42668762). None is a trial. Widening the search to tirzepatide and GLP-1 returned ten records, the same six relevant ones found for the tirzepatide page and four unrelated. The trials above are not in that search at all, because they never use the word: the evidence on low semaglutide amounts sits under "dose-finding", not "microdosing".
The arithmetic for amounts below 0.25 mg
In a powder vial, the concentration is the milligrams in the vial divided by the water added. Units on a U-100 syringe = mg ÷ mg/mL × 100.
| Amount | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|
| 0.05 mg | 2 units | 1 unit | 0.5 units |
| 0.1 mg | 4 units | 2 units | 1 unit |
| 0.125 mg | 5 units | 2.5 units | 1.25 units |
| 0.15 mg | 6 units | 3 units | 1.5 units |
| 0.2 mg | 8 units | 4 units | 2 units |
| 0.25 mg | 10 units | 5 units | 2.5 units |
Where those concentrations come from: 2.5 mg/mL is a 5 mg vial with 2 mL; 5 mg/mL is a 5 mg vial with 1 mL or a 10 mg vial with 2 mL; 10 mg/mL is a 10 mg vial with 1 mL. The amounts here are ten to fifty times smaller than the tirzepatide equivalents, so at the strongest concentration most rows fall below the smallest mark on a 1 mL barrel; the dilute column is the one in which these figures are readable at all. The mg to units page sets out the formula and the tenfold misreadings, the semaglutide reconstitution page works each vial size, and the semaglutide calculator preset does it for any figure entered.
Why the half-life matters more here than for tirzepatide
The labels give semaglutide an elimination half-life of approximately 1 week, and the Ozempic label adds that it "will be present in the circulation for about 5 weeks after the last dose." With once-weekly injection, half of each dose is still present when the next is given, so at steady state the level after each injection is about twice what a single injection gives alone, approached after four to five weeks. Tirzepatide's 5-day half-life gives a factor of about 1.6. That is arithmetic from the label figures, not a measured result for sub-0.25 mg amounts. It means a small weekly amount builds for a month before it settles, and takes about as long to leave.
What is not established
No trial has tested once-weekly semaglutide below 0.25 mg for weight management; the only year-long low arm dosed daily. No trial has tested reduced portions from multi-dose pens. The labels describe no use below 0.25 mg. The trial figures above describe arms run under medical supervision and are not a basis for any amount; decisions about amounts belong with a prescriber.
Sources and dates
Opened 2026-09-24: the Ozempic label (DailyMed set id adec4fd2-6858-4c99-91d4-531f5f2a2d79, published 2026-06-10), sections 2, 3, 12.3 and the instructions for use; the Wegovy label (set id ee06186f-2aa3-4990-a760-757579d8f77b, published 2026-06-30), section 2 and 12.3; ClinicalTrials.gov v2 records NCT02453711 (with posted outcome measures), NCT00696657 and NCT02461589; the abstracts of Nauck et al., Diabetes Care 2016 (PMID 26358288) and O'Neil et al., Lancet 2018 (PMID 30122305); the PubMed searches described above via NCBI E-utilities. Weekly totals and accumulation arithmetic by this site. Corrections go to the contact page.