Questions to Ask Your Pharmacist About Herbs and Supplements
Plain questions to bring to a pharmacist about herbs, supplements and medicines, with the reason behind each one, drawn from NIH, FDA and NHS pages.
Content last updated . This page has not been medically reviewed.
Emergency first: for collapse, seizure, trouble breathing or swelling of the face or throat, call 911. For a possible poisoning, call Poison Help at 1-800-222-1222 (US). A pharmacy visit is for planned questions, not emergencies.
Why ask a pharmacist
Pharmacists see your full medicine list and answer questions about how medicines work together. The NHS in England describes pharmacists as able to "give advice about medicines", including how to use a medicine and worries about side effects. [1] The FDA advises talking to a doctor, pharmacist or other healthcare professional before deciding to use a dietary supplement. [2]
The main concern behind most of the questions is simple. The FDA explains that certain supplements can change absorption, metabolism or excretion of a medicine, so you may get too much or too little of the medicine you need. [3]
Before you go
- Write a list of everything you take, including supplements, teas and oils. Use the printable medicine and supplement list.
- Bring the packages if you can, so the label can be read.
- The National Institute on Aging suggests filling prescriptions at one pharmacy, so "your records are in one place." [4] If you use more than one, it says to share your list with the pharmacist at each location. [4]
- It also suggests asking whether the pharmacy has a patient profile you can fill out. [4]
Questions to ask
| Question | Why it is worth asking |
|---|---|
| Could this herb or supplement affect any of my medicines? | The FDA describes supplements that can change how a medicine is absorbed or cleared. [3] The herbal supplement St. John's wort is NIH's example of a product that makes many medications less effective. [5] |
| Is anything on my list doing the same job as something else? | The National Institute on Aging warns that more than one medicine or supplement with the same active ingredient "could damage your liver or lead to other serious health problems." [4] See amounts and duplicate ingredients. |
| Should I take it with food, or avoid certain foods or drinks? | The same institute lists this as a standard pharmacist question for medicines. [4] Grapefruit is one documented case; see grapefruit and medicine interactions. |
| What does "as needed" mean, and what if I miss one? | Both are on the institute's list of questions for a pharmacist. [4] |
| Can this tablet be crushed or split? | The institute advises not to chew, break or crush tablets without first asking whether it changes how the drug works. [4] |
| Can you explain a term on my label? | The institute suggests asking the pharmacist to explain terms or abbreviations you do not understand. [4] |
| What does this label wording mean for my supplement? | NIH says the label may not match the contents, and that terms such as "standardized", "verified" or "certified" do not necessarily guarantee quality or consistency. [5] See reading supplement labels. |
| What side effects should make me call someone? | NIH advises contacting a health care provider if you have side effects from a supplement. [5] |
What a pharmacist visit cannot settle
The sources we read describe what a pharmacist can advise on for medicines. [1] They do not say that a pharmacist can confirm what is inside a supplement bottle. For quality questions see product quality and contamination.
The FDA says it is not authorized to approve dietary supplements for safety and effectiveness before they are marketed. [2] That is one reason the questions above matter.
If something goes wrong
Tell your pharmacist and prescriber. The FDA's MedWatch program receives reports from the public. [6] See how to report a side effect in the US.
Never stop or change a prescribed medicine because of what you read here. Ask the prescriber or pharmacist. For medicines with a narrow safe range, such as warfarin, digoxin, lithium, cyclosporine and tacrolimus, ask before adding anything new; see narrow-range medicines and supplements.
Frequently asked questions
Can a pharmacist tell me if an herb is safe with my medicine?
A pharmacist can advise on medicines and answer questions about them. [1] Bring your full list, because the answer depends on what else you take. For how to check an interaction with a professional, see checking an interaction safely.
Do I need to mention vitamins and teas?
Yes. NIH asks you to list all medications and supplements. [7] The National Institute on Aging says to mention everything, even products you use only now and then. [4]
Is "natural" a reason to skip the question?
No. The FDA states that natural does not always mean safe. [3]
Should I ask the pharmacist about pregnancy or breastfeeding?
Yes, and tell them if you are pregnant, breastfeeding or trying to get pregnant. NIH notes that many supplements have not been tested in pregnant women, nursing mothers or children. [5]
What if the pharmacist does not know the product?
Ask them to note it on your record and to point you to your prescriber. A product name alone may not show what is inside; NIH says labels may not match contents. [5]
References
- NHS (England). How pharmacies can help (page last reviewed July 2024). Read 2026-10-23.
- U.S. Food and Drug Administration. Information for Consumers on Using Dietary Supplements. Read 2026-10-23.
- U.S. Food and Drug Administration. Mixing Medications and Dietary Supplements Can Endanger Your Health (consumer update, content current as of 2022). Read 2026-10-23.
- National Institute on Aging (NIH, US). Taking Medicines Safely as You Age. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH, US). Using Dietary Supplements Wisely. Read 2026-10-23.
- U.S. Food and Drug Administration. MedWatch: The FDA Safety Information and Adverse Event Reporting Program. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH, US). Know the Science: Talk With Your Health Care Providers. Read 2026-10-23.