Hemp is a term for certain varieties of the Cannabis sativa species. In contrast to “marijuana,” — which is a common word for cannabis that is relatively abundant in THC — hemp has relatively little THC.

Humans have cultivated hemp plants for thousands of years for food, medicine, and textiles. Hemp may be one of the oldest known plants that humans cultivated for medicinal and nutritional purposes.

People in ancient China appear to have started cultivating hemp around 2,700 BC. According to historical records, hemp spread to Europe after expanding across Asia some 2,000–2,200 years ago.

The human relationship with hemp is a multifaceted one, with humans using hemp and parts of the hemp plant in many ways. Some records claim the spine of the first copy of the Bible, and even Christopher Columbus’s ropes and canvas sails, were made of hemp fibers.

Keep reading to learn more about the hemp plant and its uses, including its current legality, health benefits, and other uses.

Hemp plant outside.Share on Pinterest
Edwin Remsberg/Getty Images

The major difference between hemp plants and other cannabis plants comes down to their cultivation, use, and most importantly, the levels the compound delta-9 tetrahydrocannabinol (THC). THC is what causes the “high” that cannabis is famous for.

To be legally classified as a hemp plant, a cannabis plant must contain no more than 0.3% THC on a dry-weight basis. In contrast, most other cannabis plants contain between 5–30% THC.

The Cannabis sativa species contain some 480 natural components, out of which over 100 belong to a group of compounds called cannabinoids.

Some cannabinoids, primarily THC, are intoxicating, meaning they can cause someone to feel “high.” While hemp plants are low in THC, they may be abundant in other cannabinoids such as cannabidiol (CBD) which is non-intoxicating.

So far, THC and CBD are the two most widely researched cannabinoids, and both may have medicinal value.

Learn more about the differences between THC and CBD here.

Cannabis plant, especially in their natural wild state, can all look similar. However, hemp and other varieties of the cannabis may look quite different when industries cultivate them for specific purposes.

Anecdotal evidence claims that cannabis plants for hemp production tend to:

  • have skinnier leaves mostly concentrated at the top of the plant
  • have little branching or leaves below plant top to facilitate long stalks rich in hemp fibers
  • be tall, up to 20 feet
  • look like a weed and actually grow naturally in several states including Kansas and Nebraska
  • grow very close together
  • grow under a lot of different conditions and require minimal care

Meanwhile, cannabis plants grown primarily for their THC content tend to:

  • have leaves that are tightly budded, broad, or feature tiny nugget-like buds covered with small crystals or hairs
  • look like a short, fat bush from a distance
  • be heavily branched to encourage flower and THC production
  • require a controlled, humid, warm environment to grow
  • grow spaced out from other plants

For a long time, hemp plants were illegal alongside other forms of the cannabis plant such as “marijuana,” and they were classified as a Schedule I controlled substance in the U.S. Control Substances Act.

However, the 2018 Agriculture Improvement Act, also known as the 2018 Farm Bill, legalized industrial hemp and removed hemp as a controlled substance.

Under the new rules, farmers with USDA-issued licenses may produce hemp under tight regulations. In some cases, people may also grow hemp with state or tribal approval, or for certain permitted research projects.

The United States Department of Agriculture (USDA) passed a final rule outlining national hemp production regulations in early 2021.

While approved growers may produce and sell hemp legally in the US, plants that contain more than 0.3 % THC when dry are illegal because they are classified as “marijuana,” not hemp, plants.

Hemp seeds and hemp oil made from compressed hemp seeds are extremely nutritious. They are rich in protein, fiber, and magnesium. Hemp seeds also contain fairly high levels of omega-3 and omega-6 fatty acids, which may help:

  • reduce symptoms of osteoporosis (bone density loss)
  • increase cardiovascular health
  • reduce symptoms of skin condition such as eczema and dermatitis

Hemp also contains a variety of antioxidants or compounds that protect cells from damage and may help reduce the risk of cancer, including:

Protein supplements may also contain hemp flour. Some food products also contain raw hemp seeds or hemp seed oil. Hemp seed milk is also an alternative to cow milk and other less environmentally efficient products, such as almond milk.

Learn more about the health benefits of hemp seeds here.

In addition to the health benefits of nutritive components of hemp, there are also potential health benefits to non-nutritive compounds such as CBD and THC. However, more research must establish their potential health benefits and safety.

There is currently some preliminary evidence that CBD may have the potential to help treat or manage:

Some research suggests CBD may also have a neuroprotective effect, protecting brain cells. Because of its potential neuroprotective effect, CBD may help treat neurodegenerative diseases, such as dementia and Alzheimer’s disease.

Learn more about the health benfits of CBD here.

Fibers from hemp stalk are strong and used in a variety of different ways. More than 25,000 products contain hemp.

Some popular products made from hemp or hemp products include:

  • ropes
  • textiles
  • clothing
  • industrial oils and biofuel
  • cosmetics
  • home furnishings
  • paper
  • construction materials
  • bioplastics
  • health supplements
  • food

Hemp cultivation is more environmentally friendly, efficient, and versatile than a lot of other crops. Hemp crops grown for textile fiber yield roughly 600% more than flax and 250% more than cotton. The hemp plant is also capable of growing in a range of conditions and can grow quickly.

As they grow, hemp plants create a dense canopy that prevents the sun from reaching competing weeds. Industrial hemp can even grow without the need for the significant quantities of pesticides, fungicides, and herbicides required by other crops.

Given how quickly it grows, hemp is excellent at sequestering or “trapping” carbon, or absorbing carbon from the air and transforming it into plant material throughout the hemp plant. One hectare of industrial hemp crop can suck up some 15 tonnes of carbon dioxide (C02).

Hemp crops have dense, deep roots that can help prevent soil erosion and associated land loss.

Hemp’s roots are also able to draw nutrients from deep in the soil, including harmful heavy metals, and incorporate them into harmless plant matter. These qualities make hemp excellent at reclaiming, reinforcing, and decontaminating or “cleaning” soil.

Hemp differs from other forms of cannabis in several ways, including their cultivation, use, and levels of THC. Hemp also has multiple uses, and how it is cultivated is more environmentally friendly than many other crops.

More research is necessary. However, parts in hemp, such as the seed, have significant nutritive value and cannabinoids such as CBD may have the potential for a variety of health benefits.

Only producers with USDA licenses or approved plans or projects can cultivate hemp legally in the US.