SYRINGE DRAW GUIDE
P21 Draw on Insulin Syringe
Quick answer: For the standard 10 mg + 2 mL reconstitution (5000 µg/mL), a 500 µg P21 dose requires 0.1 mL, which is 10 IU on a 100-unit U-100 insulin syringe.
500 µg draw on 30u, 50u, and 100u U-100 syringes
Dose ladder - does it fit?
How draw volume changes with dose strength, plus which insulin syringe sizes will accommodate it without overflow.
| Dose | Volume | IU (100u) | 30u | 50u | 100u |
|---|---|---|---|---|---|
| 250 µg | 0.05 mL | 5 IU | ✓ | ✓ | ✓ |
| 500 µg Std | 0.1 mL | 10 IU | ✓ | ✓ | ✓ |
| 750 µg | 0.15 mL | 15 IU | ✓ | ✓ | ✓ |
| 1000 µg | 0.2 mL | 20 IU | ✓ | ✓ | ✓ |
| 1500 µg | 0.3 mL | 30 IU | ✓ | ✓ | ✓ |
How to read the draw
- Read the large numbered marks (10, 20, 30 ...) on the syringe barrel to find your IU target.
- Pull the plunger until the rubber stopper aligns with that mark, not the bevel.
- Flick the syringe to dislodge air bubbles, then push the plunger to expel any remaining air, ending at the target IU mark.
- Confirm the volume reads correctly under good light before injection.
Frequently asked
How many insulin syringe units is 500 µg of P21?
For the standard ASCEND reconstitution (10 mg vial + 2 mL BAC water = 5000 µg/mL), a 500 µg dose of P21 requires 0.1 mL, which is 10 IU on a 100-unit U-100 insulin syringe.
Which insulin syringe size is best for P21?
A 30-unit (0.3 mL) U-100 syringe gives the finest graduations for a 10 IU draw and is the preferred choice when low-dose precision matters. A 50-unit or 100-unit syringe also works.
What is the difference between U-100 and U-40 syringes for peptide use?
U-100 syringes are calibrated so that 100 units = 1 mL. Peptide reconstitution math universally assumes U-100. Never use U-40 syringes for research peptides; the scale will be wrong by a factor of 2.5x and could result in a serious dosing error.
Can I split a single P21 dose across multiple injection sites?
Some researchers split larger draw volumes across two injection sites to reduce local tissue reaction. Splitting does not change the total dose delivered or the math; it only changes site distribution. Rotate sites with each subsequent dose.
Why does the draw value matter for P21?
P21 dosing is sensitive to precise draw volume. A 1-unit error on a 100-unit insulin syringe corresponds to 5000 µg/mL times 0.01 mL of peptide; a small error in absolute volume can be a large percent error at microgram-scale doses. Use the ASCEND calculator for exact values.
Related
For research use only. Not medical advice. Always use U-100 (not U-40) insulin syringes for peptide reconstitution. ASCEND, ascendpeptide.org