What is THC? Effects, How It Works and Risks Explained

What is THC?

THC stands for tetrahydrocannabinol. It is a cannabinoid, one of the compounds that occur naturally in the cannabis plant. Cannabinoids are found in particularly high concentrations in the flowers, which are commonly used as cannabis or processed into hash.

What sets THC apart from many other cannabinoids is its psychoactive effect. It can cause feelings of relaxation or euphoria, but may also change your perception of time, make it harder to concentrate and slow down your reaction time.

How does THC work in your body?

THC interacts with the endocannabinoid system, a natural system in the body involved in processes such as mood, appetite, memory, sleep and pain perception.

This system contains several types of cannabinoid receptors. THC primarily binds to CB1 receptors, which are especially common in the brain and nervous system. This temporarily changes the way certain signals are processed in the brain.

What does THC do to you?

THC can produce both pleasant and unpleasant effects. How someone responds depends on factors such as the dose, previous experience, individual sensitivity and the setting in which cannabis is used.

Common effects include:

• feelings of relaxation or euphoria;
• an altered sense of time;
• more intense experiences of music, food and other sensory impressions;
• fits of laughter;
• increased appetite;
• a heavy or relaxed feeling in the body;
• changes in concentration and thought patterns.

A higher dose does not automatically mean a more enjoyable experience. Too much THC can instead cause dizziness, nausea, anxiety, panic, paranoia or confusion. An unpleasant experience like this is often referred to as a bad trip.

How long do the effects of THC last?

When cannabis is smoked or vaped, the effects are usually noticeable within a few minutes. They tend to be strongest during the first few hours before gradually wearing off.

Edibles, such as space cake or gummies, work differently. The THC first has to pass through the digestive system and liver, which means it can take around 30 to 90 minutes before the effects become noticeable. In the liver, THC is converted into compounds including 11-hydroxy-THC.

As a result, the effects of edible cannabis can last considerably longer. While smoked or vaporised cannabis is usually noticeable for several hours, the effects of edibles can last for up to around 12 hours.

This delayed onset can also make edibles more difficult to dose. Taking more because you do not feel anything yet can result in consuming much more THC than intended and lead to an unpleasant experience.

Which products contain THC?

THC is mainly found in cannabis flower and hash, but it may also be present in edibles, cannabis oils and vape products. The way THC is consumed has a major influence on how quickly the effects begin and how long they last.

• Cannabis flower and hash: usually smoked or vaporised, meaning the effects tend to begin relatively quickly.
• Edibles: products such as space cake and gummies take longer to kick in, but their effects can last much longer.
• THC oil: taken orally. How quickly it works and how long the effects last can vary depending on the product and how it is used.
• THC vapes: inhaled and therefore relatively fast-acting. The composition and potency can vary considerably between products.

What is the difference between THC and CBD?

THC is psychoactive, while CBD is not. Both cannabinoids occur naturally in cannabis, but they interact with the body in different ways.

THC interacts strongly with CB1 receptors in the brain and can therefore alter awareness and perception. CBD, short for cannabidiol, does not produce the same psychoactive cannabis high.

What are the side effects of THC?

THC side effects can occur during or shortly after use. Their intensity varies from person to person and depends on factors such as the dose and individual sensitivity.

Common side effects include:

• dry mouth and red eyes;
• dizziness or drowsiness;
• an increased heart rate;
• difficulty with concentration and short-term memory;
• reduced coordination and slower reaction times;
• anxiety, panic or paranoia;
• nausea or confusion.

At higher doses, or in people who are particularly sensitive, cannabis can also trigger or worsen more serious psychological symptoms.

What are the risks of THC?

The risks associated with cannabis use depend largely on how much and how often someone uses it, the age at which they start, the method of consumption and their individual sensitivity.

Important risks include:

• developing tolerance and dependence with regular use;
• an increased risk of psychological problems in people who are susceptible to them;
• additional risks associated with regular use at a young age;
• a greater risk of accidents due to slower reaction times and reduced coordination;
• exposure to harmful combustion products when cannabis is smoked.

The method of consumption also makes a difference. With edibles, for example, it can be easier to unintentionally consume too much because the effects take longer to begin.

Can THC be addictive?

Cannabis containing THC can be addictive, although not everyone who uses cannabis develops a dependence. The risk increases with frequent use, starting at a young age and long-term daily or near-daily use.

Regular use can also lead to tolerance. This means the body becomes accustomed to the effects, so a larger amount of cannabis may be needed to achieve the same effect.

Signs of problematic use can include:

• using cannabis more often than you originally intended;
• finding it difficult to cut down or stop;
• spending a lot of time using cannabis;
• continuing to use it despite problems at school, work or in relationships.

Can THC cause withdrawal symptoms?

People who use cannabis heavily and regularly may experience withdrawal symptoms when they stop or significantly reduce their use. This does not happen to everyone, and the severity of the symptoms varies from person to person.

Possible symptoms include:

• difficulty sleeping or vivid dreams;
• irritability and restlessness;
• feelings of anxiety or low mood;
• reduced appetite;
• headaches;
• strong cravings for cannabis.

Most symptoms gradually become less intense. They often improve noticeably within one to two weeks, although sleep problems can sometimes last longer.

How long does THC stay in your body?

The psychoactive effects of THC usually last for several hours, but its metabolites can remain detectable in the body for much longer.

Exactly how long varies from person to person and depends on factors including:

• the amount of cannabis consumed;
• how frequently cannabis is used;
• individual metabolism;
• the type of drug test being used.

With regular use, THC metabolites can remain detectable for longer than after occasional use. A positive test therefore does not automatically mean that someone is still high at that moment.

There is no reliable quick method for immediately removing THC from the body.