Calabar bean
Calabar bean


Calabar bean (Physostigma venenosum) is a plant. It has been traditionally used to make medicine, but the seed is extremely poisonous and can be deadly.

Calabar bean contains a chemical that affects signals between muscles and nerves. This chemical affects many parts of the body.

People use calabar bean for constipation, epilepsy, and many other conditions, but there is no good scientific evidence to support these uses. Using calabar bean is also unsafe.
When taken by mouth: Calabar bean is unsafe. It is extremely toxic and can cause paralysis, seizures, coma, and death.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Calabar bean is unsafe when taken by mouth. It may cause severe side effects, including death. Don't use it.


There is interest in using calabar bean for a number of purposes, but there isn't enough reliable information to say whether it might be helpful.
Likely effective Effectiveness definitions
Possibly effective Effectiveness definitions
Likely ineffective Effectiveness definitions
Possibly ineffective Effectiveness definitions
Insufficient evidence Effectiveness definitions

Dosing & administration

There isn't enough reliable information to know what an appropriate dose of calabar bean might be. Calabar bean might also be unsafe. Speak with a healthcare provider before using.

Interactions with pharmaceuticals

Drying medications (Anticholinergic drugs)

Interaction Rating=Minor Be watchful with this combination.

Calabar bean can increase a chemical in the body called acetylcholine. Acetylcholine plays a big part in many important body functions. Some medications, called anticholinergic drugs, block the effects of acetylcholine in the body. Taking calabar bean might decrease the effects of anticholinergic drugs.

Interactions with herbs & supplements

Herbs that affect the brain and heart (anticholinergic herbs): Calabar bean might block a chemical in the body called acetylcholine. Acetylcholine plays a big part in many important body functions. There is some concern that taking calabar bean along with other supplements with similar effects might cause increase the risk for blurred vision, confusion, increased sweating, and increased heart rate. Examples of supplements with this effect include angel's trumpet, belladonna, bitter yam, jimson weed, and scopolia.

Interactions with foods

There are no known interactions with foods. has licensed monographs from TRC Healthcare.
This monograph was last reviewed on 18/09/2023 10:00:00. Monographs are reviewed and/or updated multiple times per month and at least once per year.
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