Herbal supplements have been in the marketplace for many years. Initially, herbs were simply ground into a powder and placed into capsules, pressed into tablets or processed into a liquid.  If such herbs were processed at low heat, the consumer would get the full spectrum of constituents that make up the herb in whatever ratio those constituents naturally occurred in the herb.  As time went on, specific compounds were identified in herbs to have therapeutic effects in the treatment of various health problems.  Such discoveries led to the development of standardized herbal products where specific amounts of certain herbal constituents are made available in a product to the exclusion of other constituents.  More recently, processes have been developed that provide the full spectrum of an herbs constituents while at the same time providing specific levels of certain constituents believed to be instrumental in dealing with a specific health problem. 

       The therapeutic benefit of a medicinal plant is closely related to the chemicals found in the plant. Extraction of these chemicals requires a variety of extraction methods to get the chemicals out of the herb and into the product being prepared.  For example, while water can be used to extract some chemicals found in plants, other chemicals can only be extracted by using alcohol or some other solvent.  Sometimes the same herb may be prepared in one way to treat a specific condition and in another way to treat a completely different condition. For example, using a water extraction process may extract a delicate group of anti-inflammatory plant steroids to treat arthritis while leaving behind non-water soluble chemicals.  Yet when the same plant is exposed to an alcohol extraction process, the delicate steroids are degraded by the alcohol but different antibacterial alkaloids, which are only soluble in alcohol, are extracted instead.  So while the water extraction of the herb may be used to alleviate inflammation, the alcohol extract may be used to treat various bacterial infections.

       While some constituents can be removed from an herb by simple water extraction, many chemicals in herbs must be removed by other means.  This is especially true of the fatty components of an herb which will not separate from the herb by water extraction.  These fatty components are often the most therapeutic constituents of the herb.  Manufacturers of herbal supplements often use solvents such as hexane to extract these substances.  Hexane is a volatile hydrocarbon found in gasoline and used as an industrial solvent.  Residues of such solvents can be found in the finished product.  Some manufactures use high heat to remove fatty constituents which can degrade the fats and also destroy the water soluble constituents.

       In recent years, a process called supercritical extraction has become available to extract fatty constituents. The supercritical process uses highly compressed carbon dioxide in it gaseous state for this purpose.  This process is called supercritical because there is a critical temperature point beyond which a gas will maintain its gaseous state and not turn to a liquid.  In the case of carbon dioxide (CO2), the critical temperature point is 31 degrees centigrade. If CO2 gas is heated up to any temperature over 31 degrees centigrade (which would be over, or “super” the “critical” point), then it will not turn to a liquid no matter what the pressure.  At high compression, CO2 has the density of a liquid, but is able to penetrate deeply into an herb and dissolve the fatty constituents of that herb.  When the pressure is released, the gas dissipates into the atmosphere or can be collected and recycled.  What is left behind are the fatty constituents of the herb.  This process has been found to not damage the herbal constituents in any way and there is no residue of the CO2 in the extraction.  When done correctly, this process can provide a broad spectrum of herbal constituents in a bio-available form.

       Since not all herbal constituents can be removed through supercritical extraction, companies that use this method also use water and alcohol extraction methods when necessary to produce the desired results.  The advantage of supercritical extraction is that no harmful solvents are used and this process is able to provide most if not all of the chemical constituents that make up the herb.  While herbal products made by using supercritical extraction can be “standardized” to contain specific amounts of certain constituents, the users of such herbs are also getting the full spectrum of other constituents found in the herb.  Therefore, this approach provides whole herb benefits while at the same time providing specified levels of components that are known to provide specific therapeutic effects.     

       For example, a company called New Chapter makes available a number of supercritically extracted herbs which provide a broad spectrum of the herbs constituents while at the same time providing specific levels of particular constituents that are known for their benefits.  One such herb marketed by New Chapter is Turmeric.  Turmeric is known for its anti-inflammatory benefits which appear largely tied to compounds called curcumins found in the fatty constituents of turmeric.  By using supercritical extraction, New Chapter is able to provide a fuller spectrum of curcumins and then concentrate certain ones known to have demonstrated therapeutic levels.  Water and alcohol extraction is also used to make available additional curcumin fractions. The difference between New Chapter’s turmeric and other turmeric products is that the spectrum of curcumins is much broader and thus may provide a wider spectrum of health benefits.  New Chapter has used supercritical extraction in a number of its products.

       Supercritical extraction has added another dimension to the manner in which herbs are prepared.  This procedure allows for a greater spectrum of herbal constituents to be present in the herbal product being prepared.  However, it should not be concluded that one should only choose herbal products processed in this manner.  There are many effective herbal products in the market place.  When choosing an herbal product it is important to determine what benefit is desired and then seek out a product that will provide the greatest potential for such benefit to be obtained. This is why buying herbal products at a health food store that has knowledgeable personnel is important to obtaining the right herbal product for the health concern being addressed.