Help Measuring Small Amounts Of Miralax
In our latest Q+A, the pharmacist explains practical methods for measuring small amounts of Miralax when the cap provided for standard dosing isn't suitable.
My child has been prescribed Miralax and needs to take 2 grams of powder. I don’t have a measuring cup or the proper device to measure exactly 2 grams. What is the best alternative?
Jan 17, 2025- A digital scale is the most accurate way to measure 2 grams of Miralax if you have one available. If you don't have a scale, use a level 1/3 teaspoon or slightly less than a 1/2 teaspoon as an approximate measurement, keeping in mind this method is less precise than using a scale.
Answer
Thank you for reaching out!
I can understand the challenge you are having measuring 2 grams of Miralax as most products are designed for a standard adult dose of 17 grams (using the bottle cap as a measure). The product also comes in single use packets, but in higher amounts than 2 grams.
If you only need 2 grams, here are some tips:
1. Use a scale (best option):
I know this one seems obvious, but I wanted to include here that if you do have a scale, this is the most accurate method as you can simply weigh out 2 grams of Miralax.
2. Estimate with measuring spoons:
If you don’t have a scale, you can use a measuring spoon as an approximation.
Miralax (polyethylene glycol 3350) has a density of about 1.1–1.2 grams per milliliter (depending on the source). Based on this:
- 1/3 teaspoon (level, not packed) is about 1.8–2 grams.
- 1/2 teaspoon (level, not packed) is about 2.5–3 grams.
Because you need around 2 grams, using 1/3 of a teaspoon or slightly less than 1/2 teaspoon should be reasonably close. Be sure to keep the spoon level (not heaping) for a more accurate estimate.
I do want to point out that the manufacturer recommends using the enclosed cap (for a 17-gram dose) or a scale for precise measurements. Measuring spoons can be helpful in a pinch, but they may not be exact.
Final Words
I hope this answer helped! Reach back out anytime.
References & sources
- Polyethylene Glycol 3350 Review — AccessFDA
Glossary — Terms in This Answer
- Miralax
- A brand name for a laxative medication used to relieve constipation by drawing water into the intestines.
- Polyethylene glycol 3350
- The active chemical ingredient in Miralax that works as a stool softener and laxative.
- Density
- The measure of how much a substance weighs per unit of volume, which affects how much space a given weight of powder takes up.
- Grams per milliliter
- A unit of measurement expressing how many grams of a substance fit into one milliliter of space.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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