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Senna
Senna — what the European monograph actually supports, what it is not for, the form and how long it is meant to be used, side effects, and the 3 medicine interactions documented for it.
This is a reference page, not a diagnosis and not a prescription. Herbal products are real pharmacology: they have effects, side effects and interactions with medicines. Tell your doctor and your pharmacist everything you take, including teas and supplements, and never stop or change a prescribed medicine because of anything you read here.
What it is
Senna alexandrina Mill. — leaf and fruit (Sennae folium, Sennae fructus)
Local names across the region this site serves: senna (ET, FI) · сенна (RU).
Grouped here under Digestion, bloating and the bowel. Regulatory position: EU herbal monograph — well-established use.
What the evidence supports
The registered indication: Short-term use in occasional constipation.
Senna is a stimulant laxative and a real medicine: its sennosides are anthranoid compounds activated by gut bacteria in the colon, where they increase motility and fluid secretion, usually acting overnight. Regulators accept the clinical evidence, which is why this carries a well-established-use indication rather than a traditional one. It is also the item on this page most often misused, and for the obvious reason — it works, so people keep taking it. The limits are the content. Occasional use, not daily. Not longer than about a week without medical advice. And never for weight control: what comes off is water and stool, while prolonged use drains potassium, which weakens the bowel further and makes the original problem worse. Constipation that keeps returning needs fibre, fluid, movement and a look at causes and medicines, not an escalating laxative.
A — Recognised efficacy A European Union herbal monograph carries a well-established-use indication for a defined preparation, meaning the regulator accepted clinical evidence.
What it is not for
Weight loss, daily bowel maintenance, or abdominal pain of unknown cause. Sudden constipation with vomiting, or a change in bowel habit lasting more than a couple of weeks, needs assessment before any laxative.
Form, strength and how long
Dried leaf or pod as tea, tablets and granules, and as a component of many "detox" and "slimming" teas, where it is often the only thing in the blend that does anything.
Duration. Not more than about one week of continuous use without medical advice.
No gram figure appears on this page on purpose. The plant part, the extraction solvent and the drug-to-extract ratio together define a preparation, and a number taken from one does not describe another. The reasoning is set out on the hub; the amount that applies to you is the one printed on the pack you are holding, and a pharmacist will read it with you.
Side effects
Abdominal cramping and watery stools, which are dose-related. Prolonged use causes potassium loss and a lazier bowel. A harmless reddish-brown discolouration of urine is expected with anthranoid laxatives and is not blood.
Who should avoid it
Contraindicated in intestinal obstruction or narrowing, acute inflammatory bowel disease, appendicitis, abdominal pain of unknown cause and severe dehydration. Not for children under 12. Not recommended in pregnancy; small amounts pass into breast milk.
Interactions with medicines
| Medicine or substance | What is described |
|---|---|
| Digoxin | Potassium loss from prolonged use increases the heart's sensitivity to digoxin — a recognised route to digoxin toxicity. |
| Blood-pressure medicines, diuretics and corticosteroids | Diuretics and corticosteroids also lower potassium. Stacking either on top of a stimulant laxative compounds the loss. |
| Any medicine swallowed at the same time | Speeding transit through the gut reduces how much of another swallowed medicine gets absorbed. Anything with a narrow therapeutic margin is worth timing away from it. |
The reverse view — start from the medicine rather than the plant — is in the medicine, food and alcohol interactions reference, and summarised for every herb on this site.
Sources: European Medicines Agency — Committee on Herbal Medicinal Products (HMPC), European Union herbal monographs · checked 2026-09-06
Frequently asked questions
What is senna used for?
Short-term use in occasional constipation. Senna is a stimulant laxative and a real medicine: its sennosides are anthranoid compounds activated by gut bacteria in the colon, where they increase motility and fluid secretion, usually acting overnight. Regulators accept the clinical evidence, which is why this carries a well-established-use indication rather than a traditional one. It is also the item on this page most often misused, and for the obvious reason — it works, so people keep taking it. The limits are the content. Occasional use, not daily. Not longer than about a week without medical advice. And never for weight control: what comes off is water and stool, while prolonged use drains potassium, which weakens the bowel further and makes the original problem worse. Constipation that keeps returning needs fibre, fluid, movement and a look at causes and medicines, not an escalating laxative.
Does senna work?
Graded A here: A European Union herbal monograph carries a well-established-use indication for a defined preparation, meaning the regulator accepted clinical evidence. Weight loss, daily bowel maintenance, or abdominal pain of unknown cause. Sudden constipation with vomiting, or a change in bowel habit lasting more than a couple of weeks, needs assessment before any laxative.
How much senna should I take?
This reference does not print gram figures, because they do not transfer between preparations of different extract strength. What can be said honestly is the form and the duration: Dried leaf or pod as tea, tablets and granules, and as a component of many "detox" and "slimming" teas, where it is often the only thing in the blend that does anything. Not more than about one week of continuous use without medical advice.
What are the side effects of senna?
Abdominal cramping and watery stools, which are dose-related. Prolonged use causes potassium loss and a lazier bowel. A harmless reddish-brown discolouration of urine is expected with anthranoid laxatives and is not blood.
Does senna interact with medicines?
Yes — documented for Digoxin, Blood pressure, Absorption timing. Each one is described on this page, with a link to the medicine-side reference where one exists.
Others in digestion, bloating and the bowel
Peppermint
Symptomatic relief of minor spasms of the gastrointestinal tract, flatulence and abdominal pain, especially in irritable bowel syndrome, for gastro-resistant oil capsules; the leaf is registered for mild digestive complaints.
Caraway
Mild spasmodic gastrointestinal complaints including bloating and flatulence.
Ginger
Prevention of nausea and vomiting in motion sickness, and mild digestive complaints such as bloating.
Fennel
Mild spasmodic gastrointestinal complaints including bloating and flatulence; and as an expectorant in cough associated with a cold.
Turmeric
Relief of digestive disturbances such as a feeling of fullness and flatulence.
Liquorice
Digestive complaints including burning sensation and dyspepsia; and as an expectorant in cough associated with a cold.
Keep the whole list in one place
TempoLife logs supplements alongside food, sleep and how you actually felt — so the answer to "what are you taking?" is a screen, not a guess.