Delta-9-tetrahydrocannabinol (THC)

How Potent is Marijuana Today?

Although cannabis contains at least 400 different chemicals, its main mind-altering ingredient is THC (delta-9-tetrahydrocannabinol). A higher THC content means a stronger effect on the brain. THC levels are affected by many factors, including plant type, weather, soil, and time of harvest. Cannabis today is often produced using refined cannabis growing methods, which produces higher levels of THC and more potent marijuana. Kids today now have a wider range of potency available than was available 20-30 years ago. It is unlikely that the user is aware of the strength of their marijuana, which can be risky.

Cannabis is native to tropical and temperate climates, but is cultivated around the world. Modern illegal growing operations use sophisticated methods to produce high-potency marijuana.

Centre for Addiction and Mental Health (CAMH)

Delta-9-tetrahydrocannabinol (THC)

Scientists continue to learn a great deal about how the active ingredient in marijuana – THC – acts in the brain. 

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How Weed Works: THC

When a person smokes marijuana, the active THC travels quickly to the brain and binds to receptors. There are more receptors in the parts of the brain that control feelings of reward. This produces the drug’s effects on the brain, temporarily affecting the way a person thinks, acts and feels.

Factors that affect the Strength of Marijuana

  • Marijuana today is often produced using refined growing techniques. One technique is called hydroponics, which involves growing plants by placing the roots into nutrient solutions, instead of using traditional soil.

  • Cannabis Sativa is the species of plant that is most often used to prepare marijuana, hashish and hash. Genetic modification and cross-breeding can produce cannabis plants with higher levels of THC.

  • The flower parts and leaves of the cannabis plant contain high levels of THC. The stems and seeds contain much lower levels.

  • o   THC occurs naturally in the marijuana plant in ranges of 0.5–3%.

    o   The form of marijuana known as sinsemilla (female derivative) can have a THC content of up to 17%.

    o   In hash, THC levels range from 5%-15%.

    o   Hash oil generally contains 10% to 20% but concentrations of THC as high as 70% have been reported. It is generally considered the most concentrated form of the drug.

  • As the cannabis plant matures, its chemical makeup changes. During early growth, the main chemical in the plant is called cannabidiolic acid. Later, cannabidiolic acid is changed to cannabidiol, which later changes to THC when the plant is full-grown.

Delta-9-tetrahydrocannabinol (THC)


That is because THC is fat soluble. This means that in order for the body to break down the THC it has to dissolve in fat. This process takes more time than substances that break down in water. If someone uses marijuana again before the body has had the time it needs to break down the THC (3 days) the THC begins to build up in the fat tissue and the body never has the chance to clear out the THC entirely.

Delta-9-tetrahydrocannabinol (THC)

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