It’s a shrub whose leaves, flowers, seeds, and berries are used in teas, oils, or concentrates for a number of health problems. As a food, sea buckthorn is probably safe. Some research suggests it may also be safe when taken up to six months as a medicine.
Very few side effects from sea buckthorn have been reported. Some people have complained of swelling, high blood pressure, headache, and dizziness. When used on the skin to treat burns, it sometimes caused a rash.
It also may make you more likely to bleed, and to make your blood sugar levels to drop if you have diabetes and take medication to control it.