GLP-1 dosing errors: why the number your prescriber wrote is the only number that counts

This is a real problem, not a scare story

The FDA has received reports of dosing errors with compounded semaglutide — patients drawing many times their prescribed dose, prescribers writing doses in confusing unit conversions, and patients escalating on their own schedule. Some of those errors sent people to the hospital with severe nausea, vomiting, and dehydration. Every one of them was preventable, and the prevention is not complicated.

How dosing errors actually happen

Confusing mg with units. The classic error. Your dose is prescribed in milligrams of medication; your insulin syringe measures units of liquid volume. If a patient told to take "0.25" draws 25 units instead of 10 — or draws 0.25 mL when they needed 0.1 — they've just taken 2.5× their dose without noticing. The fix is refusing to think in one number: know your dose in mg, know your vial's concentration in mg/mL, and know the units those two facts produce. Our dose calculator exists precisely for this.

Wrong concentration, right units. Compounded vials come in different strengths — DonoMed's tirzepatide, for example, ships as 10 mg/mL for lower doses and 15 mg/mL for higher ones. Fifty units from those two vials are two very different doses. If you draw a memorized number of units without re-checking the label, a routine refill becomes an overdose or underdose. Read the label every single time; it takes ten seconds.

Self-escalation. The dosing ladder looks predictable — 0.25, 0.5, 1.0 — and some patients decide to climb it themselves when a shipment arrives early or a plateau frustrates them. Don't. Escalation timing is a clinical decision based on your response and side effects, not a calendar formality. Moving up too fast is the single most reliable way to have a miserable month.

Doubling after a missed dose. Missed last week? Taking two doses to "catch up" concentrates a long-acting medication dangerously. The correct move is always the boring one: message your provider and ask.

The five habits that make errors nearly impossible

• Know your dose in mg — if you can't state it, stop and check before injecting.
• Read the vial label every time — medication name and concentration, even on refills. Especially on refills.
• Convert deliberately — use the calculator or your pharmacy instructions, not memory.
• Re-check at the mark — after removing air bubbles, confirm the plunger sits exactly at your unit line.
• Change nothing alone — dose, timing, and escalation are conversations with your prescriber, not solo decisions.

If you think you've taken the wrong dose

Don't wait to see what happens. Contact your provider immediately, and call the Poison Help line at 1-800-222-1222 — free, 24/7, staffed by experts who handle medication errors all day. Severe vomiting, signs of dehydration, confusion, or fainting mean emergency care: call 911. Bring or photograph your vial so clinicians know exactly what and how much.

How DonoMed builds the guardrails in

Your prescription states the dose in mg with the units spelled out for your exact vial concentration. Doses we dispense are matched to sensible vial strengths, our calculator covers every dose we offer, and your provider — a person who knows your chart — is one message away before any injection you're unsure about. Guardrails only work when used, though: the label check and the mg habit are yours.

Sources & further reading

• FDA — Medications Containing Semaglutide Marketed for Type 2 Diabetes or Weight Loss
• America's Poison Centers — free 24/7 help line 1-800-222-1222
• MedlinePlus — Semaglutide Injection