Saponin compounds reduce the surface tension of liquids, and aescin itself increases the permeability of the inner vascular walls, making it easier for tissue fluids to drain into capillaries. 6 Commercial extracts of aescin from horse chestnut seeds also have been shown to reduce excessive clotting. The aescin gel reduced inflammation and tenderness in all cases over the recorded 10-hour period. 7 Horse chestnut is most often used as a tincture rather than a tea and can be applied externally. It is also sold in a massage oil.
Horse chestnut is a fairly toxic herb that can cause vomiting and sometimes paralysis.
However, cautionary notes on the internal use of this herb are conflicting. Although horse chestnut is often included in references on poisonous plants, it has high therapeutic value with low acute and chronic toxicities noted, except in children, who don't normally have varicose veins anyway. Nevertheless, this tincture should be used carefully when taken internally because the potency of commercial preparations varies widely. Since strengths and formulations vary, it is best to follow the recommended dosage on the label. Pregnant women should consult their health care practitioners before taking horse chestnut products, though the external use of gels, ointments, teas or tinctures poses no harm.