Cannabis and hemp plants contain dozens of different cannabinoids. Delta-9-THC (Δ9-tetrahydrocannabinol) is perhaps the most well known of these, even more so than CBD.

THC is the primary psychoactive compound in cannabis, meaning it’s the substance that gives cannabis its “high”. It can often be seen on mature cannabis plants as light, sticky, resinous dust that covers the plants’ flowers and leaves.

Laws and opinions around the world relating to THC have been changing rapidly in recent years, along with many studies and headlines suggesting that THC might be potentially helpful for people suffering from certain medical conditions. All this buzz has left many people asking if THC is legal where they live and how safe it is. Today we're taking a detailed look at Delta-9-THC to try to answer these questions for yourself.

Is Delta-9 legal in the UK? Where is Delta-9-THC legal?

While many newer cannabinoids are made illegal in the UK by the Psychoactive Substances act of 2016, Delta-9-THC is specifically outlawed by the Dangerous Drugs Act of 1920. This isn’t to say that law around THC is unchanging - in 2009 it was reclassified from a “class C” drug, to a “class B” drug. In-short, THC is not legal in the UK, and laws around its possession and use appear to be becoming increasingly strict. UK consumers should still stick with CBD products if they’re looking to safely explore legal cannabinoids.

THC is sometimes legally used as a medical treatment in the UK, but it is very rare and prescriptions can be hard to acquire and maintain. Most often a THC mouth-spray called “Sativex” is prescribed, most often to treat muscle pains and twitches from multiple sclerosis.

Outside the UK, laws on THC are more varied. Countries like Canada, Mexico, Thailand and South Africa have fully legalised markets for cannabis products, with many other countries, primarily in Europe and North America offering THC to medical patients through legal medical cannabis programmes.

Is Delta-9-THC safe?

Delta-9’s safety is a hotly discussed topic, with many decades of rich, detailed research having been published. Despite this, the consensus on THC’s safety is mixed and inconclusive, meaning scientists don’t always agree.

Firstly, it’s worth acknowledging that THC is very well physically tolerated by most people. This is to say that it has few-to-no effects that disrupt the body’s essential systems, like respiration and circulation. This means that even in very large doses, it is extremely rare for a person to experience effects that might harm their physical health. Users can simply “sleep it off”, without too much concern.

Instead of harm to physical health, Delta-9’s effects on mental health are much more contested. Research seems to show that people who are already predisposed to mental health disorders can have them triggered or exacerbated by consumption of THC. This means that people who may be suffering with mental health conditions or have a family history of them should probably avoid using THC until more research is completed to determine safety.

What effects does Delta-9-THC have?

It’s important to understand that THC will affect everyone differently. One person might experience very different effects to another, depending on their genetics, body weight, general health, etc.

Furthermore, while a cannabis strain might contain an amount of THC, its effects may be different than expected because of the wide variety of other cannabinoids contained in the plant, like CBD, CBN, Delta-8-THC and others. While THC extracts and isolates may have predictable contents, it is much harder to measure cannabinoid levels in a plant.

In general, people seek out THC for its positive effects like:

• Sedation. THC can help a user to relax, rest and sleep. 
• Appetite Enhancement. THC can help people to feel more hungry, with an increased appetite.
• Pain relief. Many users of THC report that it helps to manage pain.
• Euphoria. Many users of THC report that it helps them to have a positive mood.

Often THC is said to have negative side-effects like:

• Paranoia & Anxiety. THC can make a user have more worried and paranoid thoughts.
• Dry mouth. Some THC users say that it can make their mouth and lips dry.
• Red eyes. Sometimes THC makes a user’s eyes red through vasodilation. 

Is Delta-9-THC medically useful?

Delta-9-THC is used as a medical treatment throughout the world, and has been growing in popularity in the past decade for its efficacy for a number of conditions.

Another well-known medical use for THC is in the treatment of glaucoma, a condition where the optic nerve has been damaged. This condition generally increases the ocular pressure of the sufferer, meaning that there is too much pressure in the eyeball. Consumption of THC is known to lower this pressure, relaxing the eyeball and reducing the associated discomfort. In Canada and the United States this treatment is becoming increasingly well-used, alongside traditional “eye drop” based options.

These are just a few examples of how THC is used medically today. According to the Mayo Clinic, THC is a potential treatment option for all these conditions in some parts of the USA and Canada: 

• Alzheimer's Disease
• Amyotrophic Lateral Sclerosis (ALS)
• HIV & AIDS
• Crohn's Disease
• Epilepsy & Seizures
• Glaucoma
• Multiple Sclerosis & Muscle Spasms
• Severe & Chronic Pain
• Nausea or Vomiting Caused by Chemotherapy

In the UK, Cannabis can be medically prescribed, but it is very rare and still a developing area. Most commonly it’s prescribed for conditions like severe epilepsy and multiple sclerosis, in cases where other treatments haven’t worked.

Summary