Top 10 High THC Strains in Canada – A Complete Guide to Potent Cannabis Strains

Some like their food extra spicy, others prefer their workouts high-intensity and some enjoy their cannabis with high THC. Canada offers a wide range of high THC products for enthusiasts. Whether you are an advanced cannabis connoisseur or a curious newcomer, understanding THC is essential. In this article, we’ll explore what THC is, what levels are considered high, the regulations surrounding it, and the potential effects and risks. Finally, we’ll share a list of our favourite high-THC strains that have delighted fellow Canadians and earned various cannabis awards.

Understanding THC 

THC stands for tetrahydrocannabinol, the main psychoactive compound in cannabis that affects your mind and mood. It produces the “high” or intoxicating feeling associated with cannabis use. These effects can range from euphoria, relaxation, and increased appetite to altered perception of time. However, higher doses can also result in impaired coordination and cognition, anxiety, or paranoia.
Cannabis products or strains are typically classified as Indica, Sativa, or Hybrid (a mix of both), and each batch of each strain can contain varying levels of THC.

What Is Considered High THC Cannabis?

High THC levels refer to cannabis strains and products with THC concentrations significantly higher than average. The average level varies by product type. For recreational cannabis flowers, the THC concentration often ranges from 20%-25%, with anything above that generally considered high THC. Most cannabis experts agree that cannabis flowers have a biological THC limit of 30%-35%, though some argue it could be higher.

Here is a breakdown of product types and what constitutes high THC:

Flower (including pre-rolls)

Average THC concentration: 20%-25%
High THC: Above 25%

Vapes

Average THC: 80-85%
High THC: Above 85% (Some cannabis vaping products contain over 90% THC concentration)

Edibles & Beverage

Regulatory maximums: 10 mg per pack, though some lozenges and specific edible products contain 10mg THC/unit making for 100mg/pack or more.

Concentrates

Variable based on type of concentrate
Average Hash THC 35-45%
High Hash THC: Above 45%

Rising THC Levels Over Time

It’s important to note that average reported THC levels have increased over the decades. In the 1990s, the average THC level for cannabis flowers was around 4%. By 2017, it had risen to around 17%. This means that what is considered high THC in Canada now may not be considered high THC in the future. Additionally, the topic of THC percentage can be arbitrary because there is no standardised form of testing for THC percentage and so products can be manipulated and different lab standards applied to attain higher stated THC percentages. Furthermore, it is believed that a consumer’s experience of cannabis is based not just on the THC concentration, but on the synergistic interaction between cannabinoids (ie THC), terpenes, flavonoids and other such cannabis compounds.

THC Laws and Regulations in Canada

Canada has not set a legal limit on the maximum THC content allowed in dried cannabis flowers or other cannabis products for recreational or medical purposes. However, there are specific limits for certain types of cannabis products:

• Edibles, Beverages, and Topicals: The maximum allowable amount of THC per package is 10 mg (with some exception for certain capsules/lozenges).
• Cannabis Extracts and Concentrates (e.g., oils, vape cartridges): There is no specific THC limit per package, but for regulatory purposes, 7.5 grams of these products is considered equivalent to 30 grams of dried flower, which is the maximum amount allowed in public.

It’s important to remember the legal age for purchasing, possessing, and consuming cannabis. While the federal legal age is eighteen, most provinces have set it to nineteen, with strict penalties for providing cannabis to minors.

Effects, Benefits, and Risks of High THC Weed

A higher THC cannabis product in Canada may provide stronger psychoactive effects, offering a more intense “high” experience for recreational users. Though bare in mind the overall experience varies with a number of variables such as user experience, strain, method of consumption, etc.

Potential Effects and Benefits

• Intense Euphoria: strong sense of happiness and well-being.
• Deep Relaxation: state of calm and relaxation.
• Increased Appetite: enhances enjoyment of food.
• Sedation: helps with sleep, therefore possibly beneficial for those with insomnia.
• Enhanced Creativity and Productivity: reported by some users.

It is important again to note that potency and overall experience are also influenced by other compounds like terpenes, so high THC alone does not fully characterises a strain’s effects.

Medical Benefits

Higher doses of THC have been shown to be more effective for certain medical conditions when used under proper guidance, including:

• Reducing Chronic Pain: alleviating persistent pain.
• Reducing Muscle Spasms and Spasticity: beneficial for conditions like multiple sclerosis.
• Reducing Nausea and Vomiting: particularly helpful for patients undergoing chemotherapy.

Risks

While high THC cannabis in Canada may offer significant benefits and a more intense “high,” it also carries increased risks compared to lower THC concentration counterparts. These risks include:

• Adverse psychiatric effects like anxiety, paranoia, and psychosis, especially in vulnerable populations such as adolescents and those with pre-existing mental health conditions. (However, some cannabis strains high in CBD may potentially help treat anxiety.)
• Respiratory issues like bronchitis if smoked.
• Impairments in cognition, coordination, and perception, which can impact driving and other activities.
• Increased risk of developing a tolerance or dependence on high THC products.
• Potential for cannabinoid hyperemesis syndrome, characterised by severe vomiting and nausea with chronic, high-dose use.

Moderation is therefore highly advised, especially for recreational users. High-THC cannabis in Canada should be avoided by adolescents, pregnant women, and those with certain risk factors or pre-existing conditions.

High THC Strains We Recommend

Thousands of high-THC strains have been developed over the years through cross-breeding and genetic selection, with new ones continuously emerging. It’s important to remember that other compounds, like terpenes, also influence a strain’s effects, so high THC alone doesn’t determine its impact. Here are some of our curated favourite high-potency, high-THC cannabis flowers in Canada, featuring various types, THC levels, flavours, and effects:

Note: THC percentages can vary widely by brand. The ranges provided here are based on information from the packaging of products sold via the Ontario Cannabis Store (OCS) and are intended to give a general idea of potential THC levels.

Indica

Death Bubba

THC: 24-30%
Cross: Death Star and Bubba Kush.
Flavour: Pungent skunk and pine aroma.
Effects: Relief from insomnia, stress and pain. Stimulates appetite.

Alien Bubba

THC: 18-24%
Cross: Alien Kush and Bubba Kush.
Flavour: Earthy, tea, and nutty.
Effects: Deep relaxation, euphoria and stress relief.

Ice Cream Cake

THC: 20-26%
Cross: Wedding Cake and Gelato #33
Flavour: Sweet, creamy, vanilla, and buttery.
Effects: Sedating, reduces anxiety and stress, and promotes sleep.
Winner of multiple cannabis cups. Strain of the year 2019 by Leafly.

GMO Cookies/ Chem Cookies / GMO

Indica/Sativa: 90% indica, 10% sativa
THC: 26-30%
Cross: Chemdawg and GSC (Girl Scout Cookies).
Flavour: Pungent, earthy, and chemical.
Effects: Relaxation, euphoria, and relief from stress and pain​​​​​​.
Several awards including Best Indica at the Midwest Cannabis Cup.

Sativa

Durban Poison

THC: 24-30%
Cross: Landrace strain from Durban, South Africa
Flavour: Sweet, earthy, and pine.
Effects: Energizing, uplifting and focus-enhancing. Ideal for daytime use and creative activities​​​​​​.
Known for its purity and consistent high THC content.

Super Silver Haze

THC: 25-31%
Cross: Skunk, Northern Lights, and Haze.
Flavour: Citrus, earthy and sweet.
Effects: Euphoric, creative and energetic. Great for boosting mood and productivity​​​​​​.
High Times Cannabis Cup winner in 1997, 1998, and 1999.

Sour Diesel

THC: 20-25%
Cross: Chemdawg and Super Skunk.
Flavour: Diesel, pungent and earthy. 
Effects: Fast acting, uplifting, cerebral and energizing. Helps with stress and low mood.
Frequently listed among the “best of” lists from various cannabis publications.

Hybrid

Permanent Marker

Indica/Sativa: 60% indica, 40% sativa
THC: 24-30%
Cross: Biscotti and Jealousy.
Flavour: Sweet, earthy, and pungent.
Effects: Tingly, talkative, and aroused​​​​​​.
Leafly Strain of the Year 2023

Runtz

Indica/Sativa: 50% indica, 50% sativa
THC: 24-29%
Cross: Zkittlez and Gelato.
Flavour: Sweet, fruity, and creamy.
Effects: Uplifting, happy, and relaxing​​​​​​.
Leafly Strain of the Year 2020. A favourite among both recreational and medical users

Bruce Banner

Indica/Sativa: 60% sativa, 40% indica
THC: 23-29%
Cross: OG Kush and Strawberry Diesel.
Flavour: Sweet, diesel, and earthy.
Effects: Euphoria, creativity, uplifting and stress relief​​​​​.
Multiple Cannabis Cups winner, including High Times Cannabis Cup.

By now, you should have a basic understanding of THC, its effects, and its implications. When choosing a high-THC cannabis product, there are several factors to consider, such as the product category (flower, oil, edible..), the strain type (Indica, Sativa, Hybrid), and the THC levels. Additionally, consider how you will consume the product: will you be smoking, vaporizing or ingesting it? As you navigate the world of high-THC strains in Canada, remember to consider both the benefits and potential risks. If you aren’t an advanced cannabis user, start with small steps and prioritise safety. Seek guidance from your doctor or a local cannabis expert where applicable.

© Kanab Inc. – Kanab Inc. is a Toronto based cannabis retail company that honors the historical significance and uses of the cannabis plant across cultures and civilizations. Kanab has now opened its first cannabis dispensary at the intersection of Don Mills Road and York Mills Road in North York region of Toronto, Ontario (South of 401, West of 404 / Don Valley Parkway, and East of Leslie). For more info, please visit: kanab.ca