Derived from seeds of the Cannabis sativa plant, hemp oil contains polyunsaturated fatty acids. These have anti-inflammatory effects, can stimulate collagen production, and can inhibit linoleic acid oxidation when applied topically, but research shows consuming hemp oil orally is even more effective.
Hemp oil or hempseed oil is obtained by pressing hemp seeds. Cold pressed, unrefined hemp oil is dark to clear light green in color, with a nutty flavour. The darker the color, the grassier the flavour. It should not be confused with hash oil, a tetrahydrocannabinol containing oil made from the Cannabis flower, hailed by some for its medicinal qualities.
Refined hempseed oil is clear and colorless, with little flavor and lacks natural vitamins and antioxidants. Refined hempseed oil is primarily used in body care products. Industrial hempseed oil is used in lubricants, paints, inks, fuel, and plastics. Hempseed oil has found some limited use in the production of soaps, shampoos and detergents. The oil is of high nutritional value because of its 3:1 ratio of omega-6 to omega-3 essential fatty acids, which matches the balance required by the human body. It has also received attention in recent years as a possible feedstock for the large-scale production of biodiesel. There are a number of organizations that promote the production and use of hempseed oil.
Hempseed oil is manufactured from varieties of Cannabis sativa that do not contain significant amounts of tetrahydrocannabinol (THC), the psychoactive element present in the cannabis plant. This manufacturing process typically includes cleaning the seed to 99.99% before pressing the oil. There is no THC within the hempseed, although trace amounts of THC may be found in hempseed oil when plant matter adheres to the seed surface during manufacturing. The modern production of hempseed oil, particularly in Canada, has successfully lowered THC values since 1998. Regular accredited sampling of THC in Canadian hemp seed oil shows THC levels usually below detection limit of 4 ppm (parts per million, or 4 mg/kg). Legal limit for THC content in foodstuffs in Canada is 10 ppm. Some European countries have limits of 5ppm or none-detected, some EU countries do not have such limits at all.