Some liquid medicines are labeled “Shake well before use.”
This instruction means the bottle should be mixed thoroughly before measuring each dose.
Certain liquid medicines contain ingredients that can settle or separate while the bottle is sitting. Shaking helps redistribute the medicine so the measured dose is more consistent.
Why Does the Medicine Need to Be Shaken?
Some oral liquids are suspensions rather than completely dissolved solutions.
In a suspension, small particles of medicine may settle toward the bottom of the bottle over time.
If the bottle is not mixed properly, one dose may contain a different concentration of medicine than another.
How Should You Shake the Bottle?
Follow the instructions on the prescription label or product packaging.
When the label says “shake well,” close the bottle securely and mix it thoroughly before measuring the dose.
Some prescription labels specifically instruct patients to shake the suspension well before each use.
Should You Shake It Before Every Dose?
If the medication label says to shake well before use, do so before each dose unless the product instructions say otherwise.
Do not assume that shaking the bottle once earlier in the day is enough.
What Happens If You Forget to Shake It?
Do not automatically take an additional dose.
If you realize after taking a dose that you did not shake the bottle, the safest next step depends on the specific medicine and situation.
Check the medication instructions or contact a pharmacist if you are concerned about the dose you received.
Measure the Dose Carefully
After shaking the medicine, use the measuring device recommended for that product.
Depending on the medicine, this may be:
- An oral syringe
- A dosing cup
- A calibrated dropper
For some liquid products, the label specifically advises using the supplied measuring device rather than a household spoon.
Does Every Liquid Medicine Need to Be Shaken?
No.
Some liquid medicines are true solutions and may not require shaking.
Others are suspensions and do.
Always follow the directions for the specific product rather than assuming that every liquid medicine should be handled the same way.
What About Refrigerated Liquid Medicines?
Storage instructions vary by product.
Some oral suspensions require refrigeration, while others should be stored at room temperature.
For example, certain amoxicillin-clavulanate oral suspensions are labeled to be refrigerated after preparation and shaken well before each use.
Always follow the storage instructions on your specific medication label.
When to Ask a Pharmacist
Ask a pharmacist if:
- You are unsure whether the medicine needs to be shaken
- The liquid looks unusually separated or different
- You forgot to shake the bottle before a dose
- You are unsure which measuring device to use
- The storage instructions are unclear
Bottom Line
“Shake well before use” means the liquid medicine should be thoroughly mixed before the dose is measured.
For medicines that can settle or separate, proper shaking helps make the medication more evenly distributed.
Always follow the instructions on the specific product label.
Sources
- U.S. Food and Drug Administration (FDA) — Questions and Answers on Compounded Oral Suspension Medications for Pain and Fever.
- DailyMed — Ibuprofen Oral Suspension labeling.
- DailyMed — Amoxicillin and Clavulanate Potassium for Oral Suspension labeling.