Horse chestnut is a tree native to southeastern Europe. Its seed extract is promoted mainly for chronic venous insufficiency (poor blood flow in the leg veins, causing pain, swelling and itching), and also for irritable bowel syndrome and male infertility.
Also known as: Aesculus hippocastanum, horse chestnut seed extract, HCSE, buckeye, aescin.
There is no intake value, and NCCIH gives no standard amount. NCCIH says standardized seed extracts have been used safely in studies for up to 12 weeks.
It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling.
What studies show: a 2012 Cochrane review found that horse chestnut seed extract improved signs and symptoms of chronic venous insufficiency compared with placebo; six of seven placebo trials found less leg pain, six trials (502 people) found lower leg volume (about 32 mL), and one trial suggested it may work as well as compression stockings. The reviewers say larger, rigorous trials are needed (Pittler 2012). NCCIH says there is not enough research to judge it for male infertility or irritable bowel syndrome.
Safety, per NCCIH: raw horse chestnut seeds, bark, flowers and leaves are unsafe by mouth because they contain a toxic component; standardized seed extracts have it removed and are likely safe short term. Side effects can include dizziness, stomach upset, headache and itching. Little is known about pregnancy or breastfeeding. The Cochrane review found side effects usually mild and infrequent.
We could not find a single published half-life or time to peak for horse chestnut seed extract that applies to a supplement dose, so we do not list one. Plant and bee products are mixtures of many compounds, so no single figure would describe them.
How Dose Track handles peptides · Reconstitution calculator · Half-life calculator