Internally: Sea Buckthorn is an herbal medicine of "last resort" to treat constipation, or in circumstances where the stool needs to be softened, like hemorrhoids or during recovery from rectal surgery. It is a diuretic and was used as a blood purifier. Buckthorn is also used to treat gallstones and intestinal parasites. Some studies are underway to test this herb's efficacy in fighting cancer, especially leukemia. Early results look promising. Some people take it as a liver tonic.Externally – Buckthorn is used in very small amounts for skin problems. Ointment can be applied to warts or itchy body parts.