Negative side effects of sea buckthorn oil are few, and minor, with the most common being a slight queasiness when taking very high doses. This page on drugs.com states that
no serious negative effects have been documented, with many studies using “doses of seed oil taken orally in clinical trials ranged from 5 to 45 g daily for 4 to 6 months.”
Before using any herbal treatment, consult your doctor or health care professional for treatment options. When used for general health, skin care, or anti-aging, the volumes consumed internally are not high enough to prompt adverse reactions. External applications of of the oil itself have no known adverse reactions or allergies, but impurities in the product can result in allergic reactions. If you are prone to skin allergies, test on a small area and wait 24 hours before proceeding.
Much like Acai Berry, the most common “side effect” has been reported when users are taking high daily doses to aid with weight loss. This can result in loose bowel movements. Simply lowering the dosage will remedy this, so is not considered serious in any way and is why most people don’t bother reporting this as a negative side effect.
Platelet aggregation is the clotting ability of blood. A study by the Department of Biochemistry and Food Chemistry at the University of Turku in Finland found that sea buckthorn oil inhibits platelet aggregation. This may prove beneficial in certain cases where blood clots can have negative health effects. Those with Hemophilia or other blood clotting disorders should consult their physician and proceed with caution.
Sea buckthorn oil is an effective treatment for skin wounds such as burns, skin ulcers and other skin damage. It is found as an ingredient in liniments, pastes, skin plasters and suppositories, according to Purdue University. A 2009 study by the Department of Biochemical Pharmacology at the Defense Institute of Physiology and Allied Sciences in India found that sea buckthorn has significant wound healing properties without any toxicity or other side effects.
In its concentrated form, sea buckthorn oil can stain skin, clothing or other surfaces. The oil of the Sea Buckthorn Berry in particular is more of a problem as it is a dark purple color, whereas the oil of the Sea Buckthorn seed is more orange in color and not nearly as dark or prone to staining the skin. Fortunately, is is the oil from the seed that is most beneficial for topical (skin) applications. When using the oil topically, it should be diluted and spread evenly over the surface area. Use caution when applying concentrated sea buckthorn oil around clothing as it can leave an orange stain.
Positive Cholesterol Effects
A 2007 study by the Defense Institute of Physiology and Allied Sciences in India fed sea buckthorn oil to white albino rabbits with high cholesterol for 30 days, after which the rabbits’ low density lipoprotein-Cholesterol (LDL) lowered and their high-density lipoprotein-cholesterol (HDL) increased. The researchers concluded that sea buckthorn oil has significant anti-atherogenic and cardioprotective activity. It is good for the heart and lowers bad cholesterol (LDL) while increasing the good cholesterol (HDL).