Cannabis facts

Marie Law Alphabiolabs

By Marie Law, Head of Toxicology at AlphaBiolabs
Last reviewed: 02/02/2023

In this article, we take a closer look at cannabis, what it is, how it is used, the side effects of cannabis use and more.
Table of contents
  • What is cannabis?
  • What are the street names for cannabis?
  • What does cannabis look like?
  • How is cannabis used?
  • How do people behave when they take cannabis?
  • What are the side effects of cannabis?
  • What happens when you use cannabis with other drugs?
  • Which legislation covers cannabis use?
  • Can cannabis be used in medicine?
  • How long does it take for cannabis to show up in a drug test?
  • Where can I buy a drug test?

What is cannabis?

Cannabis is a drug derived from the Cannabis sativa or Cannabis indica plant, a bushy plant that grows wild in many parts of the world and is easily cultivated in Britain.

The main active ingredient in cannabis is tetrahydrocannabinol (THC), the psychoactive compound that can make the user feel happy or relaxed.

However, it can also have more serious side effects with continued use, causing a person to become paranoid or experience hallucinations.

Other forms of cannabis include:

  • Cannabinol (CBN) – a cannabinoid (compound found in the cannabis plant). Unlike THC, CBN produces few, if any, psychoactive effects.
  • Cannabidiol (CBD) – a cannabinoid that is commonly sold online and in select shops in the form of CBD oil. CBD produces few, if any, psychoactive effects. However, it is heavily regulated in the UK and must not contain more than 0.2% THC when sold over the counter.

Levels of THC, CBN and CBD can vary widely depending on several factors, including the variety of cannabis plant, and how the cannabis has been prepared (e.g. loose leaves, resin, oil etc).

What are the street names for cannabis?

Some of the most common street names for cannabis include:

  • Dope
  • Grass
  • Blow
  • Ganja
  • Hash
  • Joint
  • Weed
  • Pot
  • Moroccan
  • Marijuana

What does cannabis look like?

Cannabis can take several forms including:

  • Herbal, grass, weed, marijuana – composed of the dried leaves and flowering parts of the female cannabis plant, this form resembles compressed, dried herbs. When smoked it has a distinct, musky smell
  • Hash or cannabis resin – a black or brown lump
  • Cannabis oil – a light yellow or amber liquid

How is cannabis used?

Cannabis is most commonly inhaled, either by smoking or vaping, or ingested in hash or resin form.

It is also used as an ingredient in ‘cannabis edibles’ such as teas, sweets and cakes.

How do people behave when they take cannabis?

How a person feels and behaves after using cannabis can vary, depending on the person. Some people report feeling ‘chilled out’ and happy after using cannabis.

However, it can also make people feel lethargic, unmotivated, paranoid, confused or anxious.

What are the side effects of cannabis?

The physical side effects of cannabis can vary and depend on several factors, including how the drug is ingested, frequency of use, and the metabolism and weight of the person.

Some common side effects include:

  • Dizziness
  • Vomiting
  • Loss of concentration
  • Short-term memory loss
  • Drowsiness
  • Loss of consciousness
Long-term cannabis use can also impact fertility and lower a person’s chances of conceiving.

What happens when you use cannabis with other drugs?

Below is an overview of the side effects of using cannabis alongside other drugs.


Using alcohol and cannabis together can heighten the effects of cannabis, causing depressive effects.


Mixing cannabis and cocaine can elevate both heart rate and blood pressure, increasing the risk of heart attacks and strokes.


Using cannabis alongside depressants like heroin can be dangerous and can inhibit the proper functioning of the central nervous system.

When both substances are used together, this can significantly lower a person’s blood pressure and cause breathing to become laboured – or stop altogether.

Which legislation covers cannabis use?

Misuse of Drugs Act 1971

Under UK law, cannabis is classified as a Class B drug.

Controlled drugs refer to any substances that are tightly controlled by the government, because they pose a risk of addiction or misuse.

It is an offence for a person to have controlled drugs in their possession, unless in exceptional circumstances, such as when they have been prescribed by a doctor.

This also covers activities relating to the production, supply, or preparation of controlled drugs.

Possession Up to 5 years in prison, an unlimited fine or both
Supply Up to 14 years in prison, an unlimited fine or both

Drug Driving Road Traffic Act 2015

Drug driving Up to 6 months in prison, an unlimited fine or both
Criminal record
Driving licence endorsement for 11 years
One-year driving ban
Causing death by dangerous driving Up to 14 years in prison

Can cannabis be used in medicine?

Although rare, cannabis-based medicines may be prescribed in the UK to relieve symptoms of certain conditions.

Circumstances in which a person might be prescribed medical cannabis include children and adults with severe or rare forms of epilepsy, adults undergoing chemotherapy, and people with multiple sclerosis (MS) dealing with muscle spasms and stiffness.

However, medical cannabis would only be considered where other treatments had not helped or had been deemed unsuitable.

How long does it take for cannabis to show up in a drug test?

Even after the ‘high’ has worn off, and long after the drug was first consumed, cannabis use can be detected by a drug test, depending on the type of test you take.

The drug testing detection windows for cannabis are as follows:

  • Oral fluid (saliva) – up to 48 hours
  • Urine – up to 4 days
  • Hair – up to 12 months (depending on the length of hair available)
  • Nails – up to 12 months (up to 6 months for fingernails and up to 12 months for toenails)

Oral fluid and urine drug testing are known as ‘narrow-window’ forms of testing and can be used to detect drug use from 30 minutes after consumption, up to a few days.

This can vary depending on the type of substance and how much was used.

The rate at which hair and nails grow means that both hair drug testing and nail drug testing can provide a ‘wide-window’ of detection for drugs and their metabolites (up to 12 months).

Where can I buy a drug test?

AlphaBiolabs offers two types of home drug tests, designed to give you peace of mind or enable you to seek support for a friend or loved one who is struggling with substance misuse.

  • Home Urine Drug Test Kit (£18) – this easy-to-use home drug testing kit can detect drugs and their metabolites in a urine sample. The self-contained screening kit includes built-in test strips, allowing you to read the results in just 5 minutes
  • Drug and Alcohol Nail Test (from £99) – this test can detect drug use for a period of up to 12 months prior to samples being collected, with only a sample of fingernail clippings or toenail clippings required. Simply follow the instructions included in your test kit to collect your nail clipping samples and return them to our accredited laboratory for testing

Please be aware that our home drug test kits are for peace of mind only, and the results cannot be used in court. If you require a drug test for official matters, you will need a legally-instructed drug test.

For confidential advice about which test might best suit your needs, you can also call our Customer Services team on 0333 600 1300 or email

Home drug tests

Explore our range of at-home drug tests.

Marie Law

Marie Law

Head of Toxicology at AlphaBiolabs

A highly-skilled and respected scientist with over 13 years’ experience in the field of forensics, Marie joined AlphaBiolabs in 2022 and oversees the company’s growing toxicology team.

As Head of Toxicology, Marie’s day-to-day responsibilities include maintaining the highest quality testing standards for toxicology and further enhancing AlphaBiolabs’ drug and alcohol testing services for members of the public, the legal sector, and the workplace sector.

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