Horse Chestnut

Aesculus hippocastanum · Horse chestnut seed extract · Aescin · Escin

Snapshot

Indications	Contraindications
Chronic venous insufficiency^1–4 Hemorrhoidal bleeding⁵ Postoperative swelling⁶ Varicocele-associated infertility⁷ Bruising and local edema⁸	Raw seed, bark, or leaf use⁹ Hypersensitivity to horse chestnut⁸ Bleeding disorders¹⁰

Horse chestnut is the seed of Aesculus hippocastanum, and its standardized extract delivers aescin (escin), a saponin mixture that reduces inflammation and increases vein tone¹¹. Adults with venous leg symptoms use it for the leg pain and swelling of chronic venous insufficiency (CVI)¹.

Cochrane reviews of oral seed extract found less leg pain and smaller leg volume than placebo in the short term, with larger trials still needed^1–3. A Cochrane review of rutosides derived from horse chestnut found no benefit over placebo for post-thrombotic syndrome¹². A 2021 case report described idiosyncratic liver injury in a man taking a horse chestnut dietary supplement, a signal no trial has tested. Products listing horse chestnut number 502, mostly capsules and liquid extracts; see Form comparison.

Raw seeds, bark, flowers, and leaves are unsafe orally because of a toxic component that standardized extracts have removed⁹. Memorial Sloan Kettering's herb monograph asks patients taking warfarin, aspirin, or other blood thinners to confirm the product is free of aesculin, a hydroxycoumarin¹¹.

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

In the full monograph

54 sources, 43 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.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources