Medications on Scan Day: What to Take and What to Hold
The morning of a scan arrives with a quiet dilemma: today's pills — take or hold? The answer is medication-specific, and it is written down before you need it.
Most daily medications continue normally on scan day; the exceptions are metformin around iodine contrast, blood thinners before needle procedures, and diabetes drugs around fasting and sedation — each with a team-set schedule. The rule that outranks every other: follow your written medication sheet, and when none exists, call the facility the day before.
Which medications continue on scan day?
Blood pressure pills, heart medications, thyroid replacement, antidepressants, and most daily drugs continue on schedule — with small sips of water even when fasting. Stopping them creates the day's real risks: a skipped blood-pressure pill before an anxiety-provoking MRI, or missed thyroid dose altering nothing for the scan but everything for you. The default is continuation; the exceptions are the ones your team names in writing.
Which medications are held for scans?
- Metformin: held at iodine-contrast CT, restarted after kidney function is confirmed — the classic rule, detailed in our diabetes guide
- Blood thinners: paused for needle procedures on a procedure-specific calendar (our biopsy guide)
- Diabetes drugs and insulin: adjusted around fasting and sedation — hypoglycemia around a fasted scan is a real, preventable risk
- GLP-1 agonists (Ozempic, Wegovy): increasingly flagged before sedation because of stomach-emptying effects — disclose them to the sedation team
- Supplements with bleeding or sedation effects: per-procedure decisions (our supplements guide)
Why does the fasting rule have a water exception?
Because a small sip to swallow necessary medication is not "breaking the fast" for imaging purposes — abdominal imaging cares about a stomach full of food or large fluid volumes, not the tablespoon that carries your morning lisinopril. Facilities phrase it as "medications with small sips of water" for exactly this reason. Large gulps are different; the sheet's wording is the rule.
How do I get a written medication plan for scan day?
Ask the ordering or imaging team directly: "Which of my medications do I take on the day, and which do I hold?" Good teams hand you a sheet; if yours does not, write the answers down yourself and read them back. The plan should name each drug, its scan-day fate, and the restart time where relevant — metformin's 48-hour rule being the exemplar. Photograph the sheet; paper disappears, phones do not.
Scan-Day Medication Checklist
The week before your scan:
Educational checklist. Your facility's written instructions always override a general checklist like this one.
A medication sheet worth having?
Ask our team — then ask your facility for one.
Contact SATMED HealthFrequently asked questions about medications on scan day
Can I take my blood pressure medication before an MRI?
Yes — with a small sip of water, as usual. Holding it usually creates more risk than it prevents.
Do I stop metformin before every scan?
Only before iodine-contrast CT — and restart follows the 48-hour kidney-check rule. MRI contrast often allows continuation.
What about Ozempic before a scan with sedation?
Disclose it — stomach-emptying effects are changing sedation guidance, and the team needs days of notice.
Can I take my antidepressant on scan day?
Yes — psychiatric medications continue on schedule; stopping them abruptly is the real danger.
Do I take insulin before a fasting scan?
Adjusted, usually reduced — a fasted scan on full insulin risks hypoglycemia. Your care team sets the dose.
What if I forgot the medication instructions?
Call the facility the day before — a five-minute call replaces a morning of guesswork.
How SATMED Health makes contrast imaging safer
If your exam includes contrast, the delivery equipment matters as much as the scanner. SATMED Health engineers the systems behind every injection.
Contrast injector systems built for controlled, consistent delivery — the right dose at the right moment, every time.
Learn more →Engineered syringes for smooth, low-pressure injections that reduce discomfort and protect the vessel at the IV site.
Learn more →Patient lines and accessories designed for safe, reliable contrast administration from injector to vein.
Learn more →Contrast management solutions that help departments prepare, verify, and track every dose before it reaches a patient.
Learn more →Keep reading
More free, clinician-reviewed guides from SATMED Health.
Sources
- American College of Radiology. ACR Manual on Contrast Media — current edition.
- RadiologyInfo.org (ACR · RSNA · ASRT). How to Prepare for Your MRI Exam. Reviewed June 15, 2026.
- American College of Radiology. ACR Accredited Facilities Database.
Take the defaults, hold the exceptions
Browse more free imaging guides or reach out with any question.
Contact SATMED HealthMedical disclaimer: This article is for education only and is not medical advice, diagnosis, or treatment. Always follow the instructions of your imaging facility and your own physician. If you think you are having an emergency, call 911 (or your local emergency number) immediately.
Please note: SATMED Health is not a medical facility. Please contact your physician with specific medical questions or for a referral to a radiologist. To locate an accredited medical imaging provider in your community, search the ACR accredited facilities database. This website does not provide cost information; imaging costs vary by region.
