What Is Cannabis?
8 min readBeginner Level
A complete beginner's guide to the cannabis plant — its history, how it works in the body, and the key things you need to know.
This guide is for educational purposes only. Cannabis is illegal in the UK without a medical prescription. Always consult a healthcare professional before making decisions about cannabis use.
Cannabis is a flowering plant from the Cannabaceae family that has been used for thousands of years for medicinal, spiritual, and recreational purposes.
The plant contains over 100 cannabinoids — chemical compounds that interact with your body's endocannabinoid system, which helps regulate mood, sleep, appetite, and pain.
The two most well-known cannabinoids are THC (tetrahydrocannabinol) — the psychoactive compound that produces a 'high' — and CBD (cannabidiol), which is non-psychoactive and associated with therapeutic benefits.
Key point: Cannabis affects everyone differently. Your body weight, metabolism, tolerance, and even what you've eaten that day can change how you respond. This is why 'start low, go slow' matters — especially as a beginner.
There are three main species of cannabis: Cannabis sativa, Cannabis indica, and Cannabis ruderalis.
Sativa plants are tall and thin, originating from equatorial regions. They're traditionally associated with uplifting, energetic effects — good for daytime use.
Indica plants are shorter and bushier, originating from mountainous regions. They're known for relaxing, sedating effects — often used in the evening.
Ruderalis is a smaller species that autoflowers (flowers based on age rather than light cycle). It's rarely used on its own but is crossbred with sativa and indica to create autoflowering strains.
Most modern strains are hybrids — crosses between sativa and indica varieties — bred for specific effects, flavours, and growing characteristics. To explore specific strains and their real-world effects, DAM Live's strain index tracks thousands of varieties with live Amsterdam pricing, and Strain Genetics Archive offers an interactive look at how strains are bred and combined.
When cannabis is consumed, cannabinoids enter the bloodstream and bind to CB1 and CB2 receptors in the endocannabinoid system.
CB1 Receptors (Brain & Nervous System)
These are primarily found in the brain and central nervous system — they're responsible for the psychoactive effects of THC. When THC binds to CB1 receptors, it alters neurotransmitter release, which changes perception, mood, and cognition.CB2 Receptors (Immune System)
These are found throughout the immune system and are associated with anti-inflammatory and immunomodulatory effects. CBD has a particularly strong affinity for CB2 pathways, which explains its therapeutic potential for inflammatory conditions.The effects you experience depend on the ratio of THC to CBD, your individual body chemistry, your tolerance, and the method of consumption.
Common Effects (Low to Moderate Dose)
- Altered time perception — minutes can feel like hours
- Increased appetite ('the munchies') — caused by THC binding to CB1 receptors in the hypothalamus
- Relaxation and mild euphoria — the most commonly reported effects
- Dry mouth and red eyes — harmless side effects caused by cannabinoid receptor activation in salivary glands and blood vessels
- Enhanced sensory perception — music, food, and touch may feel more intense
Higher Dose Effects (Risks)
Higher doses or strains high in THC can cause anxiety, paranoia, dizziness, and impaired short-term memory. These effects are temporary and will pass, but they can be very unpleasant — another reason to start with a low dose.There are many ways to consume cannabis, each with different onset times, duration, and intensity. The method you choose significantly affects your experience.
Inhalation (Smoking & Vaping)
Fastest onset (seconds to minutes), effects last 1-3 hours. Vaping is generally considered safer than smoking because it avoids combustion byproducts. Dry herb vaporisers heat flower without burning it. For a full guide, see How to Vape Cannabis.Edibles
Food or drink infused with cannabis. Onset takes 30-90 minutes, effects last 4-8+ hours. Edibles are harder to dose because of the delayed onset — many beginners overconsume by taking more before the first dose kicks in. The liver converts THC into 11-hydroxy-THC, which is more potent and produces a more intense body high. See our Edibles Guide for dosing tips.Tinctures & Oils
Liquid extracts taken under the tongue (sublingually). Onset in 15-30 minutes, effects last 2-4 hours. Offers precise dosing with a dropper — good for beginners and medical patients. See our Tinctures Guide.Topicals
Creams, balms, and lotions applied to the skin. Non-psychoactive — used for localised pain and inflammation. Onset in 15-45 minutes, effects last 2-4 hours. See our Topicals Guide.Concentrates & Dabbing
Highly potent extracts (60-90% THC) vaporised using a dab rig. Extremely fast onset and intense effects. Not recommended for beginners. For a complete guide, see Concentrates & Dabbing Guide.Which Method Is Right for You?
Beginners should start with either low-THC flower via a dry herb vaporiser, or a CBD-dominant tincture. Avoid edibles and concentrates until you understand your tolerance. For a side-by-side comparison of all methods, read our Consumption Methods Compared guide.Quick Questions
About the Author
DM
Dave Mak
Dave founded The Budophile to create clear, honest cannabis education for UK beginners. With a background in health research and a network of specialist contributors, he ensures every guide is accurate, evidence-based, and practical. He also runs Baked & Rated for product reviews and The Green Prescription for medical cannabis access guidance.
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