Strophanthus

Ouabain · g-Strophanthin · Strophanthin · k-Strophanthin · Strophanthus gratus · Strophanthus kombe

Snapshot

Indications	Contraindications
Heart failure¹ Atrial fibrillation¹ Antimicrobial activity²	Polycystic kidney disease³ Narrow therapeutic window¹

Strophanthus refers to African climbing plants, including Strophanthus gratus, whose seeds yield ouabain (g-strophanthin), a rapid-acting cardiac glycoside that inhibits the sodium pump¹. That cardiotonic action drives interest in heart failure and atrial fibrillation, uses that rest on digitalis pharmacology rather than on trials of Strophanthus products¹. Strophanthus hispidus extracts also showed antimicrobial, antioxidant, and wound-healing activity in laboratory and excision-wound models.

A 2025 randomized trial in atrial fibrillation with heart failure found digoxin improved functional outcomes over beta-blockers, and circulating cardiotonic steroids, including low ouabain levels, did not alter that response⁴. A 2011 dose-finding trial of rostafuroxin, an antagonist of endogenous ouabain, found no blood pressure reduction at any dose⁵. In transfected cell lines, a 2021 study found familial hemiplegic migraine mutations in the sodium pump gene lowered ouabain-sensitive pump activity; no human trial has tested ouabain in migraine. Ouabain serves mainly as the standard research tool for cardiotonic steroids rather than a defined supplement form; see Form comparison.

A 2018 review describes a very narrow therapeutic window for digitalis glycosides, with serum digoxin levels monitored closely¹.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

38 sources, 32 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.

Snapshot

In the full monograph

Sources