After helping thousands of researchers calculate their peptide doses, we have seen the same mistakes come up again and again. Some are minor inconveniences. Others can result in taking 10x too much or too little. Here are the most common dosing errors and exactly how to avoid each one.
Mistake #1: Confusing mg and mcg
This is the single most dangerous dosing error. 1 mg = 1,000 mcg. Confusing the two means a 1000x error.
Example: A protocol calls for 250 mcg of BPC-157. If you misread this as 250 mg, you would be attempting to take 1,000 times the intended dose (which would be 50 entire vials).
Prevention: Always double-check the unit. If a dose seems unusually large (requiring most or all of a vial in one injection) or unusually small (less than 1 unit on a syringe), recheck your units.
Mistake #2: Forgetting the Reconstitution Volume
Your dose calculation depends on how much water you added. A 5mg vial with 1mL of water is twice as concentrated as the same vial with 2mL. Drawing 10 units from each gives you very different doses.
Prevention: Label every vial with the amount of water added and the resulting concentration. Use our reconstitution calculator to double-check.
Mistake #3: Reading the Wrong Syringe Scale
Insulin syringes come in 0.3mL (30 units), 0.5mL (50 units), and 1mL (100 units) sizes. The unit markings are different on each. Drawing to the "20" mark on a 0.3mL syringe gives you a different volume than "20" on a 1mL syringe.
Prevention: Always use U-100 (1mL = 100 units) insulin syringes unless you have specifically calculated for a different syringe type. Most peptide dosing guides assume U-100 syringes.
Mistake #4: Not Accounting for Syringe Dead Space
Standard syringes retain approximately 0.03-0.07mL of solution in the hub after the plunger is fully depressed. Over many doses from one vial, this waste adds up — you may get fewer doses than calculated.
Prevention: Use low dead-space syringes for expensive peptides. Alternatively, account for approximately 5-7% waste per vial in your planning.
Mistake #5: Mixing Up Vials
If you are running multiple peptides, unlabeled or poorly labeled vials are an accident waiting to happen. BPC-157 and Ipamorelin look identical once reconstituted.
Prevention: Label every vial immediately after reconstitution with: peptide name, concentration, date reconstituted.
Mistake #6: Using the Wrong Water Volume
Adding too little water creates a very concentrated solution where tiny measurement errors are amplified. Adding too much means drawing large volumes per dose, which can be uncomfortable and wasteful.
Prevention: Use our calculator to find a water volume that gives clean, round dose numbers. For most 5mg vials, 2mL is the sweet spot.
Mistake #7: Injecting Air Bubbles as Part of the Dose
Air bubbles in your syringe take up space that should be peptide solution. A large air bubble in a small dose can mean you inject significantly less than intended.
Prevention: After drawing your dose, flick the syringe to move bubbles to the top and gently push the plunger to expel them. Recheck your dose volume after removing bubbles.
Mistake #8: Not Fasting for GH Secretagogues
This is a protocol error rather than a math error, but it is equally important. Food — especially carbohydrates — blunts the GH response to peptides like Ipamorelin and GHRP-6 by up to 50-70%.
Prevention: Fast for at least 2 hours before and 30 minutes after GH secretagogue injections.
Mistake #9: Drawing from a Degraded Vial
A vial that has been reconstituted for more than 28-30 days, left at room temperature, or shows signs of cloudiness contains degraded peptide. Injecting from it gives you an unknown (and lower) actual dose.
Prevention: Label vials with reconstitution date. Discard after 28 days. Refrigerate immediately after each use. Inspect visually before each draw.
Mistake #10: Decimal Point Errors in Calculations
The most classic math error. 0.1mL is 10 units on a U-100 syringe. 1.0mL is 100 units — the entire syringe. A misplaced decimal point means a 10x dosing error.
Prevention: Always calculate doses in syringe units (not mL) to reduce confusion. Use our calculator to verify your math. If a result looks surprising, recalculate before drawing.
Quick Error-Prevention Checklist
- Verify peptide name on vial before every draw
- Confirm units (mcg not mg)
- Check reconstitution volume on label
- Calculate dose in syringe units
- Verify result makes sense (typically 5-50 units for most peptides)
- Remove air bubbles before injecting
- Check vial reconstitution date
What should I do if I think I took the wrong dose?
If you suspect an overdose, note the time, amount, and peptide. Most research peptides have wide safety margins, and a single accidental double-dose is unlikely to cause serious harm for commonly used peptides like BPC-157 or Ipamorelin. However, skip your next scheduled dose and monitor for any unusual symptoms. If you experience concerning symptoms, contact a healthcare provider.