Interactive lesson

Medicinal herbs, step by step

Interactive lesson: the home herbal medicine chest — measure and break, who must ask a doctor, how to recognise plants from the garden, meadow and hedgerow, and why comfrey is never drunk.

Free sample Chapters 1 and 2 (8 steps) are free. The full lesson comes with the Medicinal herbs module. Already bought? Unlock

This lesson is general guidance, not professional training. Local regulations and expert advice always take precedence. Read our disclaimer.

The whole lesson as text

1. What tea is

Herbal tea is support for mild complaints, not a substitute for a doctor.

Mild complaints — Colds, a scratchy throat, bloating, mild sleeplessness and small scrapes. Plants do not treat pneumonia, high blood pressure, diabetes or heart disease.
Traditional use — That is what folk tradition, the EMA monographs and classic pharmacognosy describe. It is not a promise that it will help you in particular.
A measure per cup — Flower and leaf: 1–2 g of dried herb per cup; 1 teaspoon is about 1 g. An adult drinks 2–3 cups a day.
Break and doctor — Drink a medicinal tea for 1–2 weeks, then take a break of at least a week. If the complaint does not improve within 3–5 days, see a doctor.

Why: A plant is not harmless just because it is natural. The same substance that works can also do harm: in too large an amount, for too long, with a medicine or in the wrong person.

The amounts in this lesson are for adults; the rule for children is in the next chapter.
How to make teas, tinctures and salves, with exact ratios, is in module H16-06.

2. Who must ask first

Pregnant and breastfeeding women, young children and anyone on regular medication ask before taking a medicinal tea.

Pregnancy and breastfeeding — No medicinal amounts of any plant without a doctor or midwife. Herbs as seasoning in food are fine; sage reduces milk supply.
Children — Under 1 year no herbal teas except on a paediatrician's advice, and never honey in tea (botulism). From 1 to 4 years only mild teas, on a paediatrician's advice.
St John's wort and medicines — St John's wort does not go with the pill, warfarin, antidepressants and many other medicines. Write down every household member's medicines and ask a pharmacist.
Mucilage and drowsiness — Marshmallow, mullein and linseed slow the absorption of medicines: leave 1–2 hours between them. Valerian, lemon balm, lavender and hops with sleeping pills: drowsiness, do not drive.

Why: In them the same plant works differently or changes how a medicine works. St John's wort can stop the contraceptive pill working, and hawthorn can strengthen heart medicines.

Chamomile, calendula, yarrow and arnica can cause a reaction in people allergic to ragweed and the daisy family.
Essential oils and menthol never go on the face or nose of babies and young children.