When most people hear ‘medical marijuana’, they think about flowers or bud that are
smoked. But cannabis comes in a variety of forms, including concentrated
extracts that can be taken in lots of different ways.
Cannabis extracts are growing in popularity, comprising between 30 and
of legal market sales in states that have legislation regulating
marijuana. The names for these extracts — oil, wax and shatter — refer
to the texture and consistency of the concentrate. Here’s an explanation
about these cannabis extracts and a guide to the differences between
The cannabis plant contains hundreds of compounds, including
cannabinoids, which are the chemicals responsible for the plant’s
psychoactive and medicinal properties. About 85
have been identified in cannabis, but the most common and most
frequently studied are Δ9-tetrahydrocannabinol (THC) and cannabidiol
(CBD). THC is the primary psychoactive component in cannabis and is
associated with such medicinal effects as pain
reduction. It has
been approved in a number of countries to treat spasticity in patients
with multiple sclerosis, and it
has been associated with improvements in patients with
CBD has been
shown to reduce nausea and vomiting, suppress seizures, reduce
inflammation, enhance moods and reduce pain.
The percent of active cannabinoids, referred to as potency, varies from
plant to plant and is dependent on such variables as climate,
temperature, humidity and soil conditions for the growing plant. Plants
grown indoors under controlled conditions usually have higher
than plants grown outdoors. Potency is measured as the percent of active
cannabinoids per dry weight of material. For example, average THC
concentration in cannabis varies between 1 and 20
Extracting the cannabinoids from the plant increases that potency to
between 40 and 80
The benefits of increased potency means that patients need less product
to achieve the medical results needed.
Cannabinoids are extracted from the plant by use of a solvent. Common
- Isopropyl alcohol
- Carbon dioxide
The plant material, usually consisting of the buds, flowers, stems and
leaves, is soaked in the solvent and then strained. This process is
usually repeated. The resulting liquid is then heated in a vacuum oven
to remove the solvent. The remaining resin is cannabis concentrate.
It is estimated that it takes about one ounce of marijuana plant to make six
grams of cannabis oil, or that it takes about five pounds of plant to
get 120 to 140 grams of extract.
Although the process for extracting cannabinoids can be done at home,
and there are many web sites that explain the process, there are risks.
One risk is the very real danger caused by improper ventilation and the
heating of potentially flammable solvents, such as butane. In 2014,
Colorado reported 32 home
that were confirmed as being caused by cannabis extractions. As a
result, the state passed legislation in 2015 restricting the use of
hazardous materials in the extraction process for non-licensed
manufacturers of cannabis extracts.
A second problem is control of contaminants. Some solvent may remain in
the resin despite the heating process, and the extraction process may
not remove contaminants, such as pesticides, that are used in the
growing process. For instance, Washington
which legalized recreational marijuana in 2014, tests product regularly
for salmonella, E. Coli, and other contaminants, and rejected about 13
percent of the marijuana produced in the state in 2014.
The third problem is consistent potency. Do-it-yourself production does
not necessarily have quality control over the potency of your product.
If your recommendation for medical marijuana requires a specific potency
level, you may be better off relying on a pharmaceutically prepared
Texture & Consistency of Cannabis Extracts
The texture and consistency of the cannabis extract is what gives the
extract its name. Texture can be affected by the temperature of the
heating process, the amount of moisture in the plant material and any
agitation or stirring that occurs prior to the purging phase (removal of
the solvent). Extract that appears as a thick, sticky resinous liquid is
Cannabis oil is sometimes called honey oil due to its gold color, or
butane oil in reference to the most commonly used solvent.
Extract that is thick and opaque is referred to as wax due to its
similarity to beeswax or earwax. Cannabis wax results from
crystallization caused by agitation either through stirring or rapid
heating. Wax can vary in texture from a somewhat thick liquid to candle
Shatter is more brittle and clear, and is almost glasslike in
appearance. When heated, it can be pliable, but it can also break easily
when it is cooled, hence the name.
Patients who use cannabis extract for treatment often employ
These methods heat the cannabis to a temperature lower than that of
smoking, creating a mist or vapor that can be inhaled. This makes it
ideal for patients who are experiencing nausea or who cannot or do not
wish inhale smoke. Cannabis oils also can be taken orally via a capsule,
an oral syringe or as drops under the tongue. If prepared with an edible
solvent, such as olive oil or butter, it can be used in cooking and
preparing cannabis edibles.
The potency and effects of the various forms of cannabis extract are
similar across the products. The type recommended for patients will
depend on their condition, symptoms and their provider’s