How it works
CheckMyScrip is a personal advocacy tool. When you see several doctors, each one may only know part of your list. CheckMyScrip puts the whole list in one place and reads what the official drug labels say about each medicine — and about each pair of medicines — so you can ask the right person the right question.
Where the information comes from
- FDA drug labels through openFDA: the same prescribing information and over-the-counter “Drug Facts” that come with the medicine. We read the boxed warning, contraindications, warnings and precautions, drug interactions, and the OTC “do not use” and “ask a doctor or pharmacist” sections.
- RxNorm / RxNav (National Library of Medicine): turns what you type — a brand, a generic, “Tylenol PM” — into its ingredients.
- RxClass and MED-RT (National Library of Medicine): each ingredient’s drug class, how it works, and structured “not to be combined with” and “not for people with” relationships.
What it checks
- Interactions. For every pair, we look for each medicine’s name, brand names and drug class in the other medicine’s label, both directions. We also check structured contraindications in MED-RT, and three label patterns: two medicines that both affect heart rhythm (QT), both raise serotonin, or add up to more drowsiness or slower breathing.
- Doubled-up prescriptions. The same ingredient in two products (acetaminophen is the classic one), or two medicines from the same drug class — common when two prescribers each add one.
- Your conditions, pregnancy and age. Label warnings that mention a condition you’ve listed, pregnancy or breastfeeding language in the warnings, and the label’s section on older adults.
- Prescribing cascades. When one medicine’s label lists a side effect and another of your medicines is used to treat that problem. For common side effects we only raise this when the start dates show the second medicine came later.
- Symptoms. Pick what you’re noticing and see which of your medicines’ labels list it, ranked: boxed warning, then warnings, then the general side-effect list.
- Recalls. Ongoing FDA recalls for products that contain your ingredients — shown as “ask your pharmacist to check the lot,” never “your medicine is recalled.”
Who to ask
- Medicines from different prescribers: your pharmacist first (they see the whole picture), then the prescriber who started the newer one.
- Both medicines from the same prescriber: that prescriber.
- Anything over the counter, or a medicine we couldn’t check: your pharmacist.
- Two from the same class from different prescribers: your pharmacist and your primary care doctor, who can coordinate.
- A warning about one of your conditions: the prescriber of that medicine.
- Emergency signs: 911. Possible overdose or wrong medicine: Poison Help, 1-800-222-1222. Thoughts of suicide: 988.
Questions are written in plain words and quote the label, so the person you ask can see exactly what we saw. They draw on FDA’s guidance for patients (“Will this take the place of anything else I am taking?”) and MedlinePlus (“Ask your provider if you still need to take all of the medicines on your list.”).
What it can’t see
- Doses. It doesn’t check whether a dose is right for you.
- Off-label use. Labels only describe approved uses, so a medicine used for something else won’t show up as treating it.
- Anything the labels don’t say. Some interactions are known to pharmacists but aren’t written in either label.
- Many supplements. Supplements don’t have FDA labels. We still check whether your other medicines’ labels mention them.
- Your history. Kidney and liver function, lab results, allergies and how long you’ve done well on a medicine all matter. That’s why every flag ends in a question for a person, not an instruction.
- It doesn’t include the AGS Beers Criteria or the ISMP high-alert list (both need permission to reproduce). We link to their consumer pages instead.
How it scored when we tested it
We ran it on live FDA and NLM data against published lists. These are tests of the method, not a guarantee for your list.
| Test | Result |
|---|---|
| 15 high-priority interactions chosen by an expert panel (Phansalkar et al., JAMIA 2012), one example medicine per class | 15 of 15 flagged; 13 at the top level (“ask soon”), 2 at “next visit” |
| 9 prescribing cascades from the ThinkCascades expert list (Drugs & Aging 2022) | 7 of 9 found. The 2 missed rely on off-label use or a side effect the label doesn’t name. |
| 8 everyday pairs with no expected problem | 7 came back clean. The 8th (sertraline + levothyroxine) is a real interaction stated in the levothyroxine label. |
Your privacy
Your profile, conditions, prescribers and symptoms never leave your device. To look medicines up, your browser sends the medicine names — and only the names — to the FDA and the National Library of Medicine. See Privacy.
Not medical advice
CheckMyScrip is information to help you ask better questions. “Always consult your doctor first before stopping or reducing a medication.” — US Deprescribing Research Network.