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Semaglutide Titration — Volume-Per-Step Schedule Table

Published 2026-06-30 · Lyophile Editorial

Reconstitution: 5 mg peptide + 2 mL bacteriostatic water (0.9% benzyl alcohol, USP <797> compliant) = 2500 mcg/mL. On a U-100 insulin syringe: 1 unit = 0.01 mL = 25 mcg.

| Titration Step | Dose (mcg) | Volume (mL) | U-100 Units | Syringe Mark | |----------------|------------|-------------|-------------|--------------| | 1 | 250 | 0.10 | 10 | 10-unit line | | 2 | 500 | 0.20 | 20 | 20-unit line | | 3 | 750 | 0.30 | 30 | 30-unit line | | 4 | 1000 | 0.40 | 40 | 40-unit line | | 5 | 1500 | 0.60 | 60 | 60-unit line | | 6 | 2000 | 0.80 | 80 | 80-unit line |

Each step assumes a 4-week hold. Table works for any 5 mg vial reconstituted to 2 mL total volume. Adjust if you change diluent volume — the math is the same.

The Math Behind the Table

5 mg = 5000 mcg. 5000 ÷ 2 mL diluent = 2500 mcg/mL. One U-100 unit = 0.01 mL. 2500 × 0.01 = 25 mcg per unit.

For 250 mcg: 250 ÷ 25 = 10 units. For 500 mcg: 500 ÷ 25 = 20 units. For 2000 mcg: 2000 ÷ 25 = 80 units.

Check your math: 10 units × 25 mcg/unit = 250 mcg. 80 units × 25 mcg/unit = 2000 mcg. Numbers must match. If they don't, redo the arithmetic.

Common failure mode: Using a 1 mL syringe marked in 0.01 mL increments (100 divisions) but confusing it with a U-100 insulin syringe. U-100 syringes are calibrated for insulin concentration (100 units/mL). A 1 mL tuberculin syringe has 100 tick marks at 0.01 mL each — same physical volume per tick but different labeling. Confirm your syringe type before drawing.

Reconstitution Concentration Options

The table above uses 2 mL diluent for 5 mg peptide. You can vary this.

2 mL diluent: 2500 mcg/mL. Doses from 250-2000 mcg require 10-80 units. Sweet spot for 5 mg vials.

1 mL diluent: 5000 mcg/mL. 50 mcg per unit. For 250 mcg: 5 units. For 2000 mcg: 40 units. Smaller draw volumes — harder to measure precisely. A 5-unit draw on a U-100 syringe is one air bubble away from 4 or 6 units.

3 mL diluent: 1667 mcg/mL. ~16.7 mcg per unit. For 250 mcg: ~15 units. For 2000 mcg: ~120 units. Requires two injections at higher doses since a U-100 syringe maxes at 100 units. 120 units = one 100-unit injection plus one 20-unit injection.

Rule of thumb: Choose a concentration where your smallest dose fills at least 5 units on the syringe. Below 5 units, measurement error from dead space and air bubbles exceeds 10% of the target dose. USP <1226> on analytical method validation notes precision degrades below 10% of scale — same principle applies here.

Syringe Selection and Measurement

U-100 insulin syringes come in 0.3 mL (30 units), 0.5 mL (50 units), and 1.0 mL (100 units) capacities. For the table above (10-80 unit draws), a 1.0 mL syringe covers all steps. For step 1 (10 units), a 0.3 mL syringe offers finer resolution — each tick = 0.5 units instead of 1 unit.

Half-unit syringes: Some 0.3 mL U-100 syringes have half-unit markings (0.005 mL = 12.5 mcg at 2500 mcg/mL). These help at low doses but add error from reading between lines. If you use half-unit marks, verify the syringe is labeled "½ unit" or "0.5 unit" on the package. Not all 0.3 mL syringes are half-unit.

Dead space: Standard insulin syringes have ~0.02-0.04 mL dead space in the hub and needle. At 10 units (0.10 mL), dead space represents 20-40% of the drawn volume. Low dead space (LDS) syringes reduce this to ~0.003 mL. For research where dose accuracy matters, use LDS syringes.

Air bubbles: Tap the syringe barrel after drawing. A single 1 mm bubble in a 0.10 mL volume displaces ~0.005 mL — 5% of the dose. At 10 units, that's 12.5 mcg lost. At 80 units, it's 1.25 mcg lost. Small doses amplify the error. Always expel air before injecting.

Titration Schedule Rationale

The table follows a graduated increase: 250 → 500 → 750 → 1000 → 1500 → 2000 mcg. Each step represents a 50-100% increase over the previous dose in early steps, then smaller relative increases later. This is standard for peptide research where tolerance development is expected.

Why 4-week holds: Peptide pharmacokinetics show steady-state serum concentrations reach ~95% of plateau after 4-5 half-lives. Semaglutide's half-life is approximately 1 week in vivo. Four weeks = 4 half-lives = ~94% of steady state. Shorter holds risk cumulative effects. Longer holds waste time.

Why not skip steps: The 250→500→1000→2000 mcg sequence appears in published protocols. Skipping the 750 and 1500 mcg steps doubles the dose increase from 1000 to 2000 mcg — a 100% jump. Most protocols avoid >100% increases to minimize acute effects. The table includes intermediate steps for smoother progression.

Common Errors and How to Avoid Them

Error 1: Reconstituting with the wrong volume. If you add 1 mL instead of 2 mL, the concentration doubles. Your 10-unit draw becomes 500 mcg instead of 250 mcg. Mark the vial with the final concentration after reconstitution.

Error 2: Using a syringe with different units. U-100 syringes are for insulin (100 units/mL). A U-40 syringe (40 units/mL) has different volume per unit. Never mix syringe types. Always check the package: "U-100" must be printed on the barrel.

Error 3: Not accounting for dead space in multi-dose vials. When drawing from a vial, the dead space in the needle hub is filled with peptide solution. If you draw 10 units and inject, the needle hub holds ~1-2 units that never reach the injection site. For multi-use vials, each draw loses ~1-2 units to the hub. Over 8 draws, that's 8-16 units lost — enough to affect the last dose. Use LDS syringes or account for the loss by drawing slightly more.

Error 4: Storing reconstituted peptide incorrectly. Semaglutide in bacteriostatic water (0.9% benzyl alcohol) is stable for 28 days when refrigerated at 2-8°C (36-46°F). USP <797> requires sterile compounding areas to maintain this range. Freezing damages the peptide. Room temperature accelerates degradation. A 4-week titration schedule fits within the 28-day window. If your schedule runs longer, reconstitute a fresh vial.

Practical Workflow

  1. Remove vial cap. Wipe rubber stopper with 70% isopropyl alcohol swab. Let dry 30 seconds.
  2. Draw 2 mL bacteriostatic water into a 3 mL syringe with an 18-20 gauge needle.
  3. Inject water slowly down the vial wall — not directly onto the lyophilized powder. Gentle reconstitution prevents foaming.
  4. Swirl gently. Do not shake. Shaking denatures the peptide.
  5. Let sit 5-10 minutes until fully dissolved. Solution should be clear, not cloudy.
  6. Label vial with date, concentration (2500 mcg/mL), and researcher initials.
  7. Refrigerate at 2-8°C. Use within 28 days.
  8. For each dose, draw the volume from the table using a fresh U-100 insulin syringe.
  9. Expel air bubbles. Verify volume at eye level.
  10. Inject subcutaneously per your protocol.

Where to Source Bacteriostatic Water

Bacteriostatic water (0.9% benzyl alcohol, USP grade) is available from several suppliers. Ensure the product is labeled as sterile and non-pyrogenic. Look for USP <71> sterility testing on the certificate of analysis.

For research use only — not clinical guidance. Always verify sterility and storage conditions upon receipt. Discard any vial with visible particulates or cloudiness.