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Semaglutide dose in units: how dosing is measured and why it matters. | Reddit

Last updated September 19, 2026

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“Semaglutide dose in units” is one of the most searched dosing questions among patients new to compounded GLP-1 therapy. The confusion is understandable: branded auto-injector pens abstract away the measurement; compounded vials put the measurement in your hands. This guide explains the measurement system, the titration logic, and what to ask your clinician before drawing your first dose.

Quick answer

Semaglutide doses are measured in micrograms (mcg) or milligrams (mg), but when drawing from a compounded vial with an insulin syringe you measure volume in “units” — which are syringe calibration marks, not pharmacological units like IU. The exact number of units to draw depends entirely on the concentration your pharmacy dispensed (e.g., 2.5 mg/mL, 5 mg/mL, 10 mg/mL).

Never calculate the volume independently without confirming the concentration label — a mg/mL vs. mcg/mL mix-up produces a 1,000-fold dosing error.

Key takeaways

  • Doses run from 0.25 mg (250 mcg) at start up to 2.4 mg (2,400 mcg) weekly at the STEP 1 maintenance dose.
  • “Units” refer to U-100 insulin-syringe markings (100 units per mL), not insulin-style international units.
  • At 2.5 mg/mL, a 0.25 mg dose is 0.1 mL = 10 units; the same dose at 5 mg/mL is just 5 units — concentration changes everything.
  • Standard titration steps up every 4 weeks: 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg weekly.
  • Compounded semaglutide is not FDA-approved and is prepared by USA-based 503A pharmacies under clinician oversight.

How is semaglutide dose measured?

Semaglutide doses are measured in milligrams (mg) or micrograms (mcg). One milligram equals 1,000 micrograms. Published clinical trial doses range from 0.25 mg (250 mcg) during the initial titration phase up to 2.4 mg (2,400 mcg) at the weight management maintenance dose in the STEP 1 trial.

In a branded auto-injector pen, the prescribed dose is dialed in and the volume is delivered automatically. In a compounded semaglutide vial, the patient draws the appropriate volume from the vial using an insulin syringe. That is where “units” enter the picture.

Insulin syringes are calibrated in “units” (U-100 is the most common standard: 100 units per mL). In the context of semaglutide dosing, “units” is a syringe volume measurement, not a pharmacological potency unit like the international units (IU) used for insulin or growth hormone. The two uses of “units” are unrelated. Confusing them is a meaningful dosing risk.

How do you convert semaglutide mcg to units on a syringe?

The bridge between your prescribed dose in mcg and the number of units you draw is the concentration of your specific compounded preparation. Concentration is expressed as the amount of semaglutide (in mg or mcg) per unit volume (typically per mL).

Common compounded semaglutide concentrations include 2.5 mg/mL, 5 mg/mL, and 10 mg/mL, though concentrations vary by pharmacy and prescription. If your compound is 2.5 mg/mL and your prescribed dose is 0.25 mg, you draw 0.1 mL — which on a U-100 insulin syringe corresponds to 10 units.

Prescribed dose@ 2.5 mg/mL (U-100 units)@ 5 mg/mL (U-100 units)@ 10 mg/mL (U-100 units)
0.25 mg (250 mcg)10 units5 units2.5 units
0.5 mg (500 mcg)20 units10 units5 units
1.0 mg (1,000 mcg)40 units20 units10 units
1.7 mg (1,700 mcg)68 units34 units17 units
2.4 mg (2,400 mcg)96 units48 units24 units

Important: This table is for educational reference only. Always confirm the exact unit volume to draw with your prescribing clinician or compounding pharmacy before your first injection — vial concentrations vary by pharmacy and prescription.

Do not perform this conversion independently. Your prescribing clinician or compounding pharmacy will tell you exactly how many units to draw for your dose, based on the concentration of your specific vial. The math is not complicated, but an error in concentration (e.g., mistaking mg/mL for mcg/mL) produces a 1,000-fold dosing error. Always confirm the unit volume with your pharmacy before administering your first injection.

The same dose can be 10 units in one vial and 2.5 in another — concentration, not the dose itself, decides how many units you draw.

What is the standard semaglutide titration schedule?

GLP-1 receptor agonists are dosed on a gradual escalation schedule for a practical reason: the gastrointestinal side effects (nausea, vomiting, diarrhea, constipation) that many patients experience are dose-dependent and reduce significantly when the dose is escalated slowly. Rushing titration is the most common reason patients experience unnecessary GI burden.

The titration schedule used in the STEP 1 trial (the largest published weight management trial for semaglutide) was structured as follows:

  • Weeks 1–4: 0.25 mg (250 mcg) weekly — the starting dose, purely for tolerability, not expected to produce maximum effect.
  • Weeks 5–8: 0.5 mg (500 mcg) weekly.
  • Weeks 9–12: 1.0 mg (1,000 mcg) weekly.
  • Weeks 13–16: 1.7 mg (1,700 mcg) weekly.
  • Week 17 onward: 2.4 mg (2,400 mcg) weekly — the maintenance dose used in the trial.

Clinicians prescribing compounded semaglutide may use a similar escalation structure or adapt it based on individual patient response and tolerance. Some patients plateau at an intermediate dose and do not escalate to 2.4 mg — that is a clinical decision, not a protocol failure. Clinician review determines your specific schedule.

What affects how high a dose you’ll need?

Dose requirements are not uniform across patients. Factors that influence the dose at which a patient achieves meaningful response include:

  • GI tolerability: The most common reason a dose is held at an intermediate level rather than escalated. Nausea, vomiting, or significant GI disruption at a given dose level typically means the clinician will pause escalation and reassess.
  • Metabolic response: Some patients experience significant appetite suppression and satiety response at lower doses and do not require the maintenance dose to achieve their clinical goals.
  • Body weight: Heavier patients may require higher doses to achieve comparable pharmacodynamic effects. This is not universal — individual sensitivity varies — but it is a factor clinicians consider.
  • Concurrent medications: Some medications affect GI motility or interact with GLP-1 receptor agonist pathways. A complete medication review is part of the clinical intake.

Administration: subcutaneous injection, weekly cadence

Semaglutide for weight management is administered as a subcutaneous injection once weekly. Common injection sites include the abdomen (at least two inches from the navel), outer thigh, or upper arm. Sites should be rotated each week to avoid accumulation at a single site.

The injection is given with the same type of syringe used for insulin — a short, fine-gauge needle that makes the injection straightforward for most patients after the first few administrations. Your pharmacy and clinical team will review injection technique at the start of your protocol.

Day of week does not clinically matter for semaglutide’s pharmacokinetics — the half-life of approximately one week means the steady- state concentration is similar regardless of which day you inject. Consistency on the same day each week is a practical recommendation, not a pharmacological requirement.

Compounded semaglutide: sourcing and oversight

Compounded semaglutide is not the same product as branded injectable semaglutide. It is not FDA-approved. It is prepared by licensed 503A compounding pharmacies in the USA for individual patients with valid prescriptions, during periods of documented shortage.

At PepScribe, compounded semaglutide is prepared in the USA by licensed 503A pharmacies. No hidden overseas supply chain. Every prescription is issued by a licensed clinician after reviewing your intake. Ongoing check-ins are part of the program — not optional extras. The clinical oversight is what makes this a physician-supervised protocol rather than a mail-order supplement.

The semaglutide dosage chart: titration schedule by phase

The weekly-injection ladder from STEP 1, four weeks per step from 0.25 mg to 2.4 mg, is the one most weight-management protocols follow and the one compounded protocols are usually written against. The pace is the clinician’s to slow. The current Wegovy label allows a further step to 7.2 mg for some patients, and the oral form has its own ladder; neither changes the compounded weekly schedule below.

PhaseWeeksDose, once weeklyPurpose
Introduction1 to 40.25 mgTolerability established
Step 15 to 80.5 mgFirst therapeutic tier; appetite effect begins
Step 29 to 121.0 mgWhere some patients settle; the label maintenance doses are 1.7 and 2.4 mg
Step 3 (if indicated)13 to 161.7 mgIf the 1.0 mg response has plateaued
Maintenance (if indicated)17 and on2.4 mgThe dose STEP 1 studied; the current label allows higher for some patients

mg to units: the draw at 2.5, 5 and 10 mg/mL

Compounded semaglutide ships at 2.5 mg/mL, 5 mg/mL or 10 mg/mL. The volume is the dose divided by the concentration; the units are that volume times 100 on a U-100 insulin syringe. The chart covers the standard ladder at all three. Read your own label first: the same dose is a different draw at a different concentration, and a refill can change it.

DoseAt 2.5 mg/mLAt 5 mg/mLAt 10 mg/mL
0.25 mg0.10 mL (10 units)0.05 mL (5 units)0.025 mL (2.5 units)
0.5 mg0.20 mL (20 units)0.10 mL (10 units)0.05 mL (5 units)
1.0 mg0.40 mL (40 units)0.20 mL (20 units)0.10 mL (10 units)
1.7 mg0.68 mL (68 units)0.34 mL (34 units)0.17 mL (17 units)
2.4 mg0.96 mL (96 units)0.48 mL (48 units)0.24 mL (24 units)

Mixing a lyophilized vial to reach one of those concentrations, and the injection itself, are on the how to use a semaglutide vial page.

Semaglutide with B12: what the label means for the chart

Many compounded semaglutide formulations include vitamin B12 (cyanocobalamin or methylcobalamin). There is no single semaglutide-plus-B12 chart because the B12 amount is set per formulation and stays fixed while the semaglutide dose climbs the same ladder above. Prescribers include it because food intake, and with it B12 intake, drops as appetite does. The label states the semaglutide concentration and the B12 amount per mL; dose from the semaglutide number, and treat the B12 as a passenger. Ask the pharmacy for a formulation without it if you take B12 separately.

Frequently asked questions

How do I read a semaglutide dosage chart?

Two columns matter: the dose in mg your clinician prescribed, and the concentration in mg/mL on your vial label. Volume in mL is dose divided by concentration; units on a U-100 syringe are that volume times 100. The chart on this page shows all three for 2.5, 5 and 10 mg/mL; your label wins if it differs.

How long does semaglutide titration take?

The standard ladder reaches 2.4 mg at week 17: four weeks at each of 0.25, 0.5, 1.0 and 1.7 mg. Clinicians hold a step longer for side effects, and many patients stay at 1.0 or 1.7 mg because that is where their response settled.

How much B12 is in a semaglutide plus B12 injection?

There is no standard. The B12 (cyanocobalamin or methylcobalamin) is set per formulation by the pharmacy and prescriber and stays fixed while the semaglutide dose climbs, so the label on your vial is the only chart that applies. More B12 does not mean more weight effect; it is there to cover intake that drops as appetite does.

What happens if I miss a semaglutide dose?

If it is within a few days of the usual day, take it and continue the weekly schedule; if the next dose is close, skip the missed one rather than doubling. Two or more missed weeks usually mean re-titrating from a lower step, which is the clinician's call.

What does "semaglutide dose in units" mean?

Semaglutide doses are primarily measured in micrograms (mcg or μg). In compounded semaglutide vials, the concentration is expressed as mcg per unit of volume (typically mcg per 0.1 mL or per mL), and patients draw the prescribed volume with an insulin syringe calibrated in units. "Units" in this context refers to syringe calibration markings, not international units (IU) as used in insulin dosing.

What is the standard starting dose for compounded semaglutide?

Clinicians typically prescribe a starting dose of 0.25 mg (250 mcg) weekly for the first 4 weeks to assess tolerability. The dose is then titrated upward based on clinical response and side-effect profile. The specific titration schedule is set by the prescribing clinician.

How do I convert semaglutide mcg to units on a syringe?

The conversion depends on the concentration of your specific compounded preparation. Your pharmacy will provide a concentration (e.g., 2.5 mg/mL or 5 mg/mL), and your clinician or pharmacy will tell you exactly how many units to draw for your prescribed dose. Never self-calculate unit volumes without that concentration information from your pharmacy.

What is the maximum semaglutide dose for weight management?

The maximum dose in the pivotal weight management trial (STEP 1) was 2.4 mg (2400 mcg) weekly, and the current Wegovy label allows a further step to 7.2 mg for some patients. The 2.4 mg dose is reached after a graduated titration schedule over approximately 16 weeks. Not all patients reach or should reach the maximum dose — clinicians individualize the dose based on response and tolerability.

Is semaglutide dosing the same for weight management and diabetes management?

No. The dose ranges and titration schedules differ between weight management and metabolic management indications. Weight management protocols in published trials reached 2.4 mg weekly; metabolic management doses in those same trials were lower. A clinician prescribes based on your specific goals and clinical context.

References

  1. Wegovy (semaglutide) injection: FDA approval package. U.S. Food & Drug Administration, Drugs@FDA (2021).
  2. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine (Wilding et al.) — PMID 33567185 (2021).
  3. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT). New England Journal of Medicine (Lincoff et al.) — PMID 37952131 (2023).
  4. Semaglutide and tirzepatide effects on cardiovascular outcomes in people with overweight or obesity in the real world (STEER). Diabetes, obesity & metabolism (PubMed) (2026).

What Reddit says

r/Semaglutide20 commentsApr 2025

How do I know what the dosage is?

After switching pharmacies the poster could not tell whether the dose was 2.5 or 1, having started at 0.25 the month before, and did not believe the drug came in 2.5 to begin with. Two numbers are in play: the vial's concentration in milligrams per milliliter, and the marks on an insulin syringe, so the same 0.25 mg dose is a different number of units on a differently concentrated vial and needs recalculating with the prescriber.

Posted on Reddit

Talk to a clinician about semaglutide.

3-minute intake. Clinician review within 24 hours. Compounded in the USA by licensed 503A pharmacies. No hidden overseas supply chain.

Written by B.A. Utterback.

Educational information only. Not medical advice. Treatment decisions are made by a licensed physician.