Herbal Medicine — Safety Principles

This card exists to anchor the rest of the section, not to be read once and skipped. Every recurring safety gap flagged across the other cards here — vague dosing, missing pregnancy cautions, generic "some lookalikes can be harmful" warnings with no specifics — is a violation of one of the nine rules below.

1. Know the plant, know its lookalikes. This is the single most common gap in this whole section — edible umbellifers (carrot-family plants like wild carrot, fennel, and yarrow) resemble poisonous hemlocks closely enough that "I'm pretty sure" isn't a safe identification standard.
2. Use the correct plant part. The same plant can be safe in one part and toxic in another — elderberry's flowers and fully ripe, cooked berries are the safe parts; the rest of the plant isn't. Mullein's leaves and flowers are fine; its seeds contain rotenone.
3. Match the application to the preparation. External-use-only doesn't mean internal-use-fine at a lower dose — foxglove is the textbook case (a real heart medication topically studied, genuinely dangerous swallowed). Comfrey works the same way for burns and broken skin specifically.
4. Follow real dosages, and use extra caution with children. "A few drops as needed" isn't a dose — it's the absence of one. Children need proportionally smaller amounts and closer attention, not just a scaled-down guess.
5. Watch tannin-rich herbs and kidney-stone risk. The same oxalate/tannin mechanism that makes lamb's quarters and spinach a moderation food applies to concentrated herbal preparations too — habitual daily use of a tannin-heavy tea or tincture isn't risk-free just because the plant is common.
6. Start low, wait 24–48 hours, and watch for individual sensitivity. Standard patch-test logic applies to internal use too, not just topical — a new herb deserves a small first dose and a day or two of attention before it becomes a routine.
7. Pregnancy, infancy, and old age change the rules. Yarrow, mugwort, goldenseal, comfrey, and black cohosh are avoid-in-pregnancy herbs, full stop. Ginger and cayenne are caution-in-pregnancy, not avoid-outright. This is more specific than any generic "consult a doctor" line, and worth remembering by name.
8. Know your limits. Start with gentle culinary herbs — thyme, oregano, rosemary in food amounts. Save concentrated internal use of a genuinely potent herb (wild lettuce, chaparral, anything with a real drug-interaction profile) for a trained herbalist's guidance, not a Pinterest card.
9. Keep learning, and don't mistake "traditional" for "harmless." Herbs can cause real harm if misused. Every card in this section that reads as more cautious than its source pin is applying that lesson directly.