Companies use different extraction methods to coax the compounds out of plants. Differences in plant constituent profiles and component ratios are often a product’s major selling point and the formulas and systems used will differ depending on the plant, the system of medicine used by the company, their philosophy, and the type of finished product: whether tincture, tea, capsules, tablets
Extraction varies in scale and method – from extracting plant constituents from freshly harvested herbs with organic alcohol in glass jars to rooms lined with huge stainless steel vats extracting plant constituents with ethanol or other solvents. In a journey following plants through the supply chain, it may be challenging to relate to huge steel vats where there’s no plant in sight. Yet, this is increasingly how herbal supplements are produced on a large scale. And so it is important to understand the issues involved to make good decisions about what questions to ask and what products to buy.
Issues in Manufacturing
Below we introduce the key issues we focused on in the manufacturing process. We will continue to develop this section of the website.
Finished product companies often outsource numerous steps of the manufacturing process to contract or private-label manufacturers. Contract manufacturing by its very nature relies developing a relationship with a third party whose company name may not appear on a label, one of the many complexities in bringing plants from the field to a consumer product. The process can be complex. Quality depends on the relationships maintained at each step of the supply chain and the rigor with which the finished product company whose name is on the product label oversees the entire process. In developing content for this website, we focused on companies that were actively involved in sourcing their raw materials and in visiting and auditing the contract manufacturer to ensure that their standards were maintained. Many companies may not maintain that close relationship
To produce a standardized product, a batch of herbs is extracted in a water/alcohol mixture. Eventually the herbs are strained out, leaving only the liquid. Then the water is evaporated until a gooey substance remains. This is a solid extract. There are many ways to produce extracts and processed vary from plant to plant or the form of the finished product. Herbal products of phytomedicines by definition contain the totality of constituents within a plant or plant part, rather than a single isolated chemical component. In herbal medicine, it is generally believed that effectiveness depends upon the synergy of many components in the plant, rather than a single isolated chemical compound. Single compounds more closely resemble a pharmaceutical model rather than an herbal model, which is based on the use of the whole plant. Standardized extracts may be stronger and in manufacturing, provide batch-to-batch consistency. It depends on the end use. A qualified herbalist can help you decide which is best suited for your needs.
A key issue in manufacturing is how the constituents are extracted. Companies may use solvents such as methanol, acetone, and ethyl acetate depending upon the extraction method and the constituents sought. Some companies may claim that solvents are absent from the finished product. Still, solvent residues may be present in a finished product. The International Conference on Harmonization has established limits for solvent residues that are the basis for the standards used by the American Herbal Products Association and are generally followed by the US botanical industry. In contrast, extracts from Asia that don’t follow these standards may have unacceptable levels of solvent residues.
Certified organic companies manage these safety issues by using only certified organic solvents and water extraction. It is worth asking non-certified organic companies how they ensure that the solvent residues are below established limits of solvent residuelevels. A company does not have to list on the label which solvents were used during processing.
As Randy Buresh of Oregon’s Wild Harvest (OWH) explained, “My belief is that those active constituents are already there. If you can get high quality plant material and process it properly in small batches from a whole [plant part] to a powder and into a capsule and do that every 6-8 weeks you are delivering the same therapeutic activity you have in a standardized extract without running it through a solvent.” You can see OWH’s process of encapsulation in the video above.
Ultimately it is up to each of us to determine what level of processing we are comfortable with. We can then encourage companies to raise the bar on their sustainability and quality standards overall.