Everything, with doses: supplements are pharmacology, per NCCIH - St. John's wort guts birth control and antidepressants, high-dose vitamin E and fish oil move bleeding risk before surgery, magnesium and calcium block thyroid-medication absorption, and biotin distorts thyroid and troponin lab tests.
The other reason: the list changes how symptoms get read - magnesium diarrhea and green-tea-extract liver injury are findable only on the table. The practice: one running list (bottle photos work), at every visit, updated on change. "Natural" is not a safety category.
What to do
Common questions
What does my doctor need to know about supplements?
Everything you take - names, doses, and why - because supplements are pharmacology whether or not they need a prescription, per NCCIH's guidance. Why it matters, concretely: interactions - St. John's wort speeds the breakdown of dozens of drugs including birth control, antidepressants, and transplant medications; high-dose vitamin E, fish oil, garlic, and ginkgo affect bleeding, which matters before surgery and with blood thinners; magnesium and calcium can block absorption of thyroid medication and some antibiotics if taken together; and biotin (in hair and nail supplements) distorts common lab tests including thyroid and troponin - enough that the FDA has warned about it. The other reason: your supplement list changes how your symptoms are read - fatigue on high-dose B12 masking, diarrhea from magnesium, liver injury from concentrated green-tea extract: these are findable only if the list is on the table. The practice: keep one running list (photo of the bottles works), bring it to every visit, and update it when anything changes. "Natural" is not a safety category: potent is potent. Pymander, a free AI doctor available 24/7 by text, can help you check an interaction.