← The ApothecaryPlantaginaceaeleaf (industrial extraction only)Fact-checked 24 October 2026

Toxic — not for home useAll parts contain cardiac glycosides. Poisoning causes nausea, vomiting, weakness, slow heart rate, high potassium, heart block and ventricular arrhythmias. In a 2017 case, a woman who drank tea made from foxglove she mistook for comfrey died of refractory ventricular arrhythmia despite digoxin antibody fragments and ECMO.In an emergency, call your local emergency number or poison centre.

Woolly foxglove

Digitalis lanata

The foxglove whose leaves are the source of digoxin, a cardiac glycoside prescribed for heart failure and abnormal heart rhythms. The whole plant is poisonous, digoxin itself needs ECG and blood-test monitoring, and people have died after mistaking foxglove leaves for comfrey. It has no place as a home remedy.

What it is used for

Heart
Strong
Digoxin is an approved prescription drug for heart failure and abnormal heart rhythms. In the 1997 DIG trial of 6,800 patients with heart failure, digoxin did not change overall mortality (35% in both groups) but reduced hospitalisation for worsening heart failure (26.8% vs 34.7%).^1,2
Fluid retention
Traditional
Foxglove (historically D. purpurea, later also D. lanata) was used for 'dropsy', the fluid retention of heart failure, which William Withering described in 1785; this is now treated with prescribed drugs, never the leaf.³

How it is prepared

dry extract / capsule

Only as purified digoxin tablets, capsules, elixir or injection, prescribed with ECG and blood-level monitoring. No preparation of the plant is safe to make at home.

Amounts are as recorded by the named source, not a recommendation.

Safety

Pregnancy: Contraindicated
Breastfeeding: Contraindicated
Children: Plant: deadly poisonous; keep away from children. The drug is used in children only under specialist care.

Interactions with medicines

St John's wortMajorListed by MedlinePlus as interacting with digoxin.
antacids, proton-pump inhibitors (omeprazole, esomeprazole, lansoprazole), calcium supplements, activated charcoal, neomycinModerateListed by MedlinePlus as interacting with digoxin; doses may need changing.

Interaction checker →

Do not use if

Any self-medication with the plant

Side effects

Digoxin: dizziness, drowsiness, blurred or yellow vision, rash, irregular heartbeat; nausea, vomiting, diarrhoea and loss of appetite can signal toxicity

Dangerous lookalikes

Foxglove leaves have been mistaken for comfrey, with fatal results.

In the healing traditions

Modern pharmacology
Digoxin, lanatoside C
Digoxin inhibits the Na+/K+-ATPase pump of heart-muscle cells, raising intracellular calcium and the force of contraction, and slows the heart rate. It was approved by the US FDA in 1954 for heart failure.
European folk medicine
Foxglove (digitalis)
Foxglove appears in the prescriptions of the Welsh Physicians of Myddfai from about 1250 and was used erratically for dropsy until Withering's account; in Denmark leaves of D. purpurea or D. lanata were standardised as digitalis powder for tinctures, infusions and tablets.
William Withering, An Account of the Foxglove (1785)

Active compounds

digoxin: cardiac glycoside; Na+/K+-ATPase inhibitor; aglycone digoxigenin
digitoxin: cardiac glycoside also present in the leaves
lanatoside C: cardiac glycoside named for the species; studied in cancer cell lines

History

Withering's 1785 Account of the Foxglove, based on Digitalis purpurea, made foxglove a standard remedy for dropsy. Woolly foxglove later became the industrial source of digoxin, which the US FDA approved in 1954 and which is still prescribed today.

Sources

Reference, not prescription. Nothing here is medical advice. Herbs can interact with medicines and be dangerous in pregnancy; tell your doctor or pharmacist about anything you take.