As a cardiac glycoside, cerberin disrupts the function of the heart by blocking its sodium and potassium ATPase.

[4] Cerberin containing plants such as Cerbera odollam have historically been used for suicide and homicide in their growth regions due to their high toxicity.

Cerberin, like all cardiac glycosides, has as its core a steroid-type set of four carbocycles (all-carbon rings).

[6] The literature on cerberin toxicity, per se, remains sparse; unless otherwise specifically indicated, the following is general information regarding cardiac glycoside toxicity, with an emphasis on information from cardenolides (i.e., steroid natural products bearing the same digitoxigenin substructure).

Those who ingest cerberin experience, within an hour, a variety of gastrointestinal and cardiac symptoms, particularly nausea, vomiting, abdominal pain, and bradycardia.

[9] Forensic sources indicate presentations for cardiac toxin poisonings that additionally include burning sensations in the mouth, diarrhea, headache, dilated pupils, irregular beating of the heart, and drowsiness; coma and death most often eventually follow.

[9] Individual cases of poisoning from Cerbera are documented including direct and indirect, and intentional and unintentional ingestion.

[9] Cases of human fatalities from consumption of crab where the crustacean had earlier consumed plants producing cerberin or related cardenolides are known.

For example, a 2004 study found that Cerbera odollam was responsible for an average of one suicide death per week between 1989 and 1999 in Kerala, India.

[14] Cerberin is ideal for use as a poison because it is fast acting, its flavor is easy to mask when added to food,[15] and it is relatively undetectable because there is only one analytical test to determine its presence in tissues after death.

Due to this inhibition it is impossible to transport sodium and potassium across the membrane and results in raising intracellular concentration of Na+.

After a cascade of cellular interactions nuclear transcription factors binds to the DNA and new enzymes will be made.

For the related digoxin, another cardiac glycoside, it is in largest part excreted unchanged by the kidneys (60-80%), with the remaining mostly metabolised by the liver.

[citation needed] This makes the renal function an important factor in the toxicity of digoxin and perhaps for cerberin as well.