🧬 Patient Guide
Strains & Terpenes
Understanding the compounds that shape your cannabis experience — from cannabinoids to the aromatic terpenes behind every strain.
Cannabinoids: The Primary Compounds
Cannabis contains over 100 cannabinoids, but two dominate the conversation:
THC (Tetrahydrocannabinol)
The primary psychoactive compound in cannabis. THC binds to CB1 receptors in the brain, producing the characteristic "high" along with therapeutic effects including pain relief, appetite stimulation, and nausea reduction. Medical cannabis flower in the UK ranges from 1–14% THC for balanced products up to 20–30% THC for high-strength products.
Higher THC doesn't necessarily mean "better" — the right strength depends on your condition, tolerance, and what balance of therapeutic effect versus psychoactivity you need.
CBD (Cannabidiol)
Non-intoxicating and increasingly studied for its therapeutic potential. CBD modulates the effects of THC, reduces anxiety, and has anti-inflammatory, anticonvulsant, and neuroprotective properties of its own. CBD-dominant products can range from 0.5% THC with 14%+ CBD down to balanced 1:1 ratios.
The Entourage Effect
The "entourage effect" describes how cannabinoids and terpenes work together synergistically — the whole is greater than the sum of its parts. THC alone produces a different, often less therapeutic and more anxiety-inducing experience than THC combined with the full spectrum of other compounds naturally present in the plant.
This is why many patients prefer full-spectrum extracts and whole flower over isolated THC. The terpenes, minor cannabinoids, flavonoids, and other compounds all contribute to the overall therapeutic effect.
Indica vs Sativa: Useful Shorthand, Not Hard Science
You'll hear that indicas are "relaxing and sedating" while sativas are "energising and uplifting." This is a useful starting point but an oversimplification. Modern cannabis strains are almost all hybrids, and the actual effects depend far more on the specific cannabinoid and terpene profile than on the plant's physical characteristics.
A better way to think about strain selection is by terpene profile — the aromatic compounds that give each strain its distinctive smell and contribute significantly to its effects.
Major Terpenes and Their Effects
🍋 Myrcene
Earthy, musky, cloves
The most common terpene in cannabis. Associated with sedating, relaxing effects. Found in mangoes, hops, thyme, and lemongrass. Dominant in many "indica" strains. May enhance THC absorption across the blood-brain barrier.
Found in: OG Kush, Granddaddy Purple, Blue Dream
🌲 Pinene
Pine, fresh forest
The most abundant terpene in nature. Associated with alertness, memory retention, and bronchodilation (opening airways). May counteract some of THC's short-term memory effects. Found in pine needles, rosemary, and basil.
Found in: Jack Herer, Blue Dream, Chemdawg
🍊 Limonene
Citrus, lemon, orange
Associated with elevated mood and stress relief. The second most common terpene in cannabis. Found abundantly in citrus fruit rinds, juniper, and peppermint. Often dominant in "sativa" strains.
Found in: Super Lemon Haze, Wedding Cake, MAC
🌸 Linalool
Floral, lavender, sweet
Associated with calming, anti-anxiety, and anticonvulsant effects. The same terpene that gives lavender its distinctive scent. Used in aromatherapy for relaxation.
Found in: Amnesia Haze, Lavender, Do-Si-Dos
🌶️ Caryophyllene
Peppery, spicy, woody
Unique among terpenes — it directly activates CB2 receptors (part of the endocannabinoid system), making it both a terpene and a dietary cannabinoid. Associated with anti-inflammatory and analgesic effects. Found in black pepper, cloves, and cinnamon.
Found in: GSC (Girl Scout Cookies), Gelato, Sour Diesel
🌿 Humulene
Hoppy, earthy, woody
The terpene that gives hops their distinctive aroma. Associated with anti-inflammatory and appetite-suppressant effects (interesting counterpoint to THC's appetite stimulation). Found in hops, coriander, and sage.
Found in: Headband, Girl Scout Cookies, White Widow
How to Choose a Strain
Rather than chasing the highest THC percentage, consider:
- What symptoms are you treating? Pain? Anxiety? Insomnia? Different profiles suit different conditions
- When are you medicating? Daytime use may call for lighter, more functional profiles; evening use for heavier, more sedating ones
- What terpene profiles appeal to you? If you've found a strain that works well, look at its terpene profile and seek similar ones
- Start low, go slow — a new strain may affect you differently. Begin with half your usual dose