Supplements and Medicine Interactions: A Simple Checklist
Educational guide · Last updated: October 4, 2026 · Not medical advice.
Key takeaways:
- Natural does not mean risk-free.
- Blood thinners, diabetes medicines, blood pressure medicines and nitrates are the most important to check.
- Bring the Supplement Facts panel to your doctor or pharmacist.
Before you start
- Make a list of every medicine, vitamin and herb you take.
- Take a photo of the Supplement Facts panel.
- Ask your pharmacist about interactions. It is usually free.
- Tell every doctor you see about supplements.
Medicines that need extra care
- Blood thinners (for example warfarin): ginkgo, pine bark, dong quai, ginger and fish oil may add to bleeding risk.
- Diabetes medicines and insulin: berberine, gymnema, cinnamon and chromium may lower blood sugar further.
- Blood pressure medicines: olive leaf, beet root and L-arginine may lower blood pressure.
- Nitrate medicines (nitroglycerin) and ED medicines: nitric-oxide products can cause a dangerous drop in blood pressure.
- Thyroid medicines: ashwagandha may affect thyroid hormones.
See it in practice
Our independent reviews list these cautions for each product, for example Phytomem One, Gluco6, Nitric Boost and Spartamax.
When to get urgent help
Seek medical care for fainting, chest pain, trouble breathing, swelling of the face or throat, yellow skin or eyes, or severe stomach pain after starting a supplement.
Sources to read next
- NCCIH: Using Dietary Supplements Wisely
- FDA: Tips for Dietary Supplement Users
- MedlinePlus: Herbs and supplements
This article is for education only and does not replace advice from your doctor or pharmacist. Healthnilo earns commissions from some links on this site; see our Affiliate Disclosure and Editorial Policy.
Related: How to read a supplement label · All guides