A recent report prepared for members of the US Congress states that “However, hemp and marijuana are genetically distinct forms of cannabis that are distinguished by their use and chemical composition as well as by differing cultivation practices in their production. While marijuana generally refers to the cultivated plant used as a psychotropic drug (whether used for medicinal or recreational purposes), hemp is cultivated for use in the production of a wide range of products, including foods and beverages, personal care products, nutritional supplements, fabrics and textiles, paper, construction materials, and other manufactured and industrial goods. Hemp and marijuana also have separate statutory definitions in U.S. law.”
Until the passage of the 2018 Farm Bill in the US, hemp and marijuana were both classified as DEA Schedule I controlled substances, defined as “drugs with no currently accepted medical use and a high potential for abuse. Some examples of Schedule I drugs are: heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), 3,4-methylenedioxymethamphetamine (ecstasy), methaqualone, and peyote.”
In the US, even though the 2018 Farm Bill loosened restrictions on hemp growing, production and marketing, the Food and Drug Administration (FDA) maintains regulatory oversight—and the FDA has not yet determined what regulations to apply to hemp and hemp products such as CBD. Currently the FDA is “Continuing to Evaluate the Regulatory Frameworks for Products Containing Cannabis and Cannabis-Derived Compounds”
By law, hemp is defined as “the plant Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers, whether growing or not, with a delta-9-tetrahydrocannabinol (Δ-9THC) concentration of not more than 0.3percent on a dry weight basis” Hemp can be used for food, food ingredients, body and cosmetic products, dietary supplements, textiles, fabrics and other manufactured goods.
In contrast, marijuana is defined by law as ““Marijuana” means any part of the plant genus Cannabis whether growing or not; the seeds thereof; the resin extracted from any part of the plant, including hashish and hash oil; any compound, manufacture, salt, derivative, mixture, or preparation of the plant, its seeds or resin. It does not include the mature stalks of the plant; fiber produced from the stalks; oil or cake made from the seeds of the plant; any other compound, manufacture, salt, derivative, mixture, or preparation of the mature stalks (except the resin extracted therefrom); or the sterilized seed of the plant which is incapable of germination.”
Legally, the main difference is that hemp and all the products derived from hemp—most commonly cannabidiol or CBD—has been removed from the Drug Enforcement Agency (DEA) list of Schedule I drugs. Marijuana, derived from a distinctly different plant, remains on the Schedule I list primarily because of higher levels of THC, or tetrahydrocannabinol. Why? Because CBD has NO psychoactive properties while THC does—more simply put, CBD will not get you “high” while THC will get you “high”.
Hemp has been cultivated around the world for millennia—evidence exists that humans have been cultivating hemp for over 10,000 years. It appears to be native to Asia, but spread rapidly due to its usefulness as food, oil and fiber. It is one of the oldest textile fibers on earth. Hemp came to the Western Hemisphere in the 16th century and was used for rope, sailcloth, paper and other materials. Hemp production in the US essentially stopped after the passage of the Marihuana Tax Act of 1938, though production continued in some parts of the world. Hemp production experienced a revitalization during WWWII due to the need for rope and other materials but was soon once again banned.
There are a number of conspiracy-type theories regarding the hemp production ban—one famous theory is that William Randolph Hearst pushed for the ban because he feared that paper made from hemp might replace paper made from wood—and he had extensive lumber holdings. Another theory is the Andrew Mellon who was Secretary of the Treasury in 1938 had investments in early plastics and synthetic fiber companies. There are those who contend that racism was the ultimate cause of the hemp ban—during the early 20th century, the information given to lawmakers was that marijuana was a dangerous drug—and the majority of users were people of color. The film “Reefer Madness”, a cult-classic of sorts, promoted the concept of “teenagers gone wild” under the influence of marijuana. Whatever the reasons given, the ban on hemp production was essentially the result of an over-reaction to marijuana as a drug and a misunderstanding of the difference between marijuana and hemp. Whatever one’s feelings about the use of marijuana as a drug, one could certainly reasonably argue that other drugs on the DEA’s Schedule I list that includes heroin, LSD, Ecstasy and peyote are more dangerous.
Figure 1: Poster for Reefer Madness
Today, hemp can be used to produce food, body care products, paper, fabric, biofuel, building materials, textiles, rope and various other materials and products—including cannabidiol or CBD. It is highly biodegradable and there is much interest in using hemp to replace plastics. All of the plant can be used, but for CBD extraction, mainly the leaves (bearing trichomes, the cannabinoid-producing glands) and stems are used.
As a food and source of hempseed oil, hemp is highly nutritious. Hemp is a complete protein, providing all the essential amino acids. Hemp seeds are high in iron, zinc, calcium, sulfur, magnesium and potassium and contains omega-3 and omega-6 essential fatty acids. Hemp is also rich in Vitamin E, beta carotenes, B vitamins and plant sterols.
Hempseed oil is derived from the seeds of the hemp plant and only contains trace amounts of CBD—the cannabinoid is produced in a mature plant. Hempseed oil can be used as a nutritious cooking oil and for body care—it is a moisturizing and hydrating oil that also contains antioxidants such as beta-carotenes and Vitamin E.
Industrial hemp can be grown in many different climates and soils and is reasonably pest-and disease resistant, though it is susceptible to fungal diseases. It grows best in loose, well-aerated loam soil and should be fertilized regularly.
Another difference between hemp and marijuana is that marijuana tends to be grown in small, controlled areas, often in individual containers—hence the word “pot” to describe marijuana. Hemp, in contrast, is planted quite closely together—this is to encourage the growth of long, slender hemp fibers.
Yet another difference is in the uses of hemp and marijuana—hemp has many different uses while marijuana has one main use—as a drug. (See Table 1 for a summary of the differences)
There are distinct differences in the pattern of phytochemicals—plant substances—between hemp and marijuana. The main phytochemicals in Cannabis include cannabinoids, terpenes and phenols (flavonoids) along with fatty acids, amino acids and other compounds including variants and metabolites of all these substances.
The major difference is that all strains of hemp contain low amounts of THC while containing high amounts of CBD. That is, in fact, the criterion by which botanists distinguish between hemp and marijuana—hemp has a high CBD to THC ratio.
The types of cannabinoids found in Cannabis—and for the most part, uniquely in Cannibis, include the following which are converted () by a process called decarboxylation into the better- known cannabinoids:
For reasons that are probably based in the genetics of hemp, very little THC is produced with CBD being the most common cannabinoid in hemp.
Figure 2: An Example of Cannabis trichomes. Released in the Public Domain by Psychonaught (talk)
The cannabinoids are synthesized in large part in the trichomes on the flowering head of the plant. Trichomes are plant glands which resemble hairs and may also be found on the leaves and stems of the plant.
Based on genetic analysis, hemp and marijuana have been determined to be botanically two different strains—a simpler way of putting it is that these two plants are related, but more like cousins than siblings. A recent report about the genetic differences stated “Using 14,031 single-nucleotide polymorphisms (SNPs) genotyped in 81 marijuana and 43 hemp samples, we show that marijuana and hemp are significantly differentiated at a genome-wide level, demonstrating that the distinction between these populations is not limited to genes underlying THC production.” In other words, hemp and marijuana are different plants—but that the differences are more than just the differential production of THC. These genetic differences are the basis for the botanical divisions of different strains of plants.
How did hemp and marijuana become so genetically distinct? The answer lies in selective breeding of the plants. Hemp was selectively bred for its fiber strength, its nutritional value and for greater seed production. High CBD production appears to have been fortuitous. In fact, when the Stanley brothers, founders of Charlotte’s Web and one of the first producers of CBD products first realized that their plants were producing large amounts of CBD, they thought they had made a mistake—who would want a CBD producing plant? Marijuana on the other hand, was selectively bred for high THC production. Currently, the marijuana strain with the highest THC content is “The White” with an average of 24.3% THC. On the low end, a strain might have 3% THC—10 times higher than what is allowed in CBD products.
Chemically, CBD and THC are both cannabinoids—but different molecules. The differences are marked in Figure 3 with yellow circles. It may not seem like much of a difference, but the body recognizes the differences—and, importantly, responds differently to CBD and THC.
The main difference is the CBD is non-psychoactive and does not get you high while THC is responsible for the well-known high from marijuana.
CBD and THC bind to different receptors in the body—and these receptors, known as CB1 and CB2 are found in different locations in the body. THC binds to the CB1 receptors (found mainly in the brain and spinal cord) and produces a sense of euphoria. CBD on the other hand binds to CB2 receptors found on immune cell, peripheral nerve cells and the digestive system. However, the binding of CBD to the CB2 receptor is more subtle—it changes the shape of the receptor to some degree and by changing the shape, it can alter the function.
Figure 3: The Chemical Structures of THC and CBD. Chemical differences are highlighted by the yellow circles
You may have seen products like hemp oil, hempseed oil, CBD oil and others. Are there differences between these? Yes—and here they are:
Cannabis oil is also known as hash or honey oil and is derived from marijuana—not hemp– plants. It is also known as dabs or BHO. The THC content is likely to vary, but THC is the main cannabinoid in cannabis oil. Because it has THC, it will get you “high”.
Cannabis oil has to be extracted from marijuana buds or flowers—and the extraction methods are the same as used for CBD extraction—solvent or CO2extraction. The “B” in BHO stands for the solvent butane—though these are risky because butane can stay in the oil as a contaminant.
Cannabis oil can be vaped, taken orally, used topically or added to edibles.
There are many chemical, genetic and use differences between hemp and marijuana. And, importantly, there are differences between the main commercial cannabinoids—CBD and THC—that are produced from hemp and marijuana.
The crucial difference between CBD and THC is that CBD is not a psychoactive substance whereas THC is. These substances have different chemical structures and different actions on the body. They are derived from two different plants that just happen to be cousins in the same family—and if you have any cousins, you KNOW how different they can be!
Table 1 is a summary of the main differences between hemp and marijuana and between CBD and THC.
Table 1: A Summary of the Differences Between Hemp and Marijuana
|THC level||Low||High (ranges from ~3-upto 27%, depending on the harvest)|
|Legal||Yes, if THC ≤0.3%||
|Types of Products||
||Medical and recreational drug use|
||Flowers and buds|