The short answer is 0.25 mg once weekly for the first four weeks. The longer answer has three parts. The number comes from the approved product’s label. No compounded vial has a label of its own. And the step that goes wrong is not choosing the dose. It is drawing it.
What the labeled ladder actually is
The prescribing information for the approved injection sets a fixed escalation schedule and tells prescribers to titrate every four weeks [5]. Every rung below is four weeks long.
| Weeks | Weekly dose | What this rung is for |
|---|---|---|
| 1–4 | 0.25 mg | Starting dosage. Not a treatment dose. |
| 5–8 | 0.5 mg | First escalation step. |
| 9–12 | 1 mg | Second escalation step. |
| 13–16 | 1.7 mg | Third step — also a valid maintenance dose. |
| 17 and onward | 1.7 mg or 2.4 mg | Maintenance for weight reduction. |
Two provisions matter more than the numbers. If a dose is not tolerated, the label says to consider delaying escalation by four weeks rather than pushing on. Miss two or more consecutive weekly doses and escalation restarts at a lower dose. You do not resume where you left off. That second rule catches people who travel, run out, or wait on a refill.
Why it starts so low
0.25 mg is not a weight-loss dose. It exists to get the gut used to the drug — the reasoning behind every published ladder. The STEP 1 to 3 trials pooled their gastrointestinal events at 2.4 mg. Nausea ran 43.9% against 16.1% on placebo. Vomiting ran 24.5% against 6.3%. Diarrhea ran 29.7% against 15.9% [2]. Those events clustered during and shortly after escalation, and 98.1% were mild to moderate.
43.9%
had nausea on 2.4 mg (16.1% on placebo)
STEP 1–3 pooled
98.1%
of gut side effects were mild or moderate
STEP 1–3 pooled
4.3%
stopped permanently because of them
STEP 1–3 pooled
<1 pt
of the weight loss was explained by them
mediation analysis
What changes when the product is compounded
The milligrams do not change. The delivery does. An approved product arrives as a pen, with the dose selected for you. A compounded product typically arrives as a vial with syringes. The arithmetic moves to your kitchen table.
A poison-control case series describes what that costs. Of three cases of compounded semaglutide administration errors, two were ten-fold overdoses. All three patients had nausea, vomiting and abdominal pain lasting days. One received a vial and syringes with no pharmacist counseling. One reported dosing in milliliters and units rather than milligrams [3]. The authors’ conclusion is about the format. Vials do not carry the safety features of a prefilled pen. Syringes not intended for semaglutide make the unit ambiguous.
Is the compounded version riskier?
One study read the FDA’s adverse event database from 2018 to 2024. It compared 707 reports involving compounded products against 81,078 GLP-1 reports in total [4]. Compounded products carried higher reporting odds on four counts. Preparation errors: ROR 48.92 (95% CI 12.63 to 189.6). Contamination: 19.00 (4.24 to 85.03). Compounding or manufacturing issues: 8.51 (5.17 to 14.0). Hospitalization: 2.35 (1.94 to 2.83).
The same study found lower reporting odds for administration errors (0.29) and dosing errors (0.24). That runs against the case-series picture. It is worth stating rather than hiding. Reporting odds ratios measure what gets reported, not what happens. A disproportionality signal is not an incidence rate. Read the direction and the intervals, not the point estimates.
So what should you actually do in week one
Start at the dose your prescriber wrote, which for a first course is almost always 0.25 mg weekly. Read the concentration printed on your vial and have whoever dispensed it confirm the mark on the syringe before the first injection. Hold each rung four weeks. If a rung is rough, the label advises staying there another four weeks rather than climbing. Miss two weeks in a row and expect to step back down. What happens at the top of the ladder is a separate question, covered in how deep a published dose ladder goes.
This guide will not tell you which concentration to buy. It will not convert milligrams to units for a specific vial. That calculation has a wrong answer, and the wrong answer sends people to hospital. The person dispensing your medication should do it with you.