The key to a successful grow is getting the right seeds for your needs! Not everyone has the same goals when they are growing cannabis indoors. For example, many recreational marijuana growers are interested in growing the highest THC strains on the market, while medicinal users want high-CBD strains.

Besides your care and love, a plant’s genetic makeup is the decisive factor behind a lot of things. such as the concentration of cannabinoids, height, yield, resistance to disease, flowering time and other biological functions.

THC count is one of these things that can be improved with some proper care but is still largely genetically predisposed. That’s why we prepared a handy list of the Top 10 High-THC marijuana strains as of early 2018. But first, let’s share some information and historical facts about THC.

What is THC and How Does it Work

Being high is amazing. This feeling of intense brain activity coupled with a tingling sensation throughout the body… You can feel it right now, don’t you? Well, all of these euphoric feelings are mainly caused by one chemical compound naturally found in the cannabis plant. You may simply know it as THC, but officially it goes by the name Tetrahydrocannabinol.

THC is the most prevalent among hundreds of active compounds found in the cannabis plant (cannabinoids) and is also the most psychoactive. Despite its current illegal status, THC’s history has been in fact closely connected with human civilization.

There are accounts of ancient Assyrians using marijuana as a psychoactive in religious ceremonies called qunubu (giving cannabis its modern name).

Cannabinoids like THC work by binding to endocannabinoid receptors concentrated in receptors found throughout our body. THC, in particular, shows a greater affinity for the CB1 receptors, found mainly in the brain. This process triggers the release of neurotransmitter responsible for feelings of euphoria and elation, similar to the ones released after getting a workout.

How Does THC Get You High

This is what we perceive as “being high”: the higher the THC count, the more intense the effects. However, as I am sure most of you can confirm, feeling high is not the only way marijuana affects us.

Depending on the strain and the condition the plant grew in, high-THC strains can induce relaxed feelings or even paranoia. It completely depends on the person and the individual organism.

Other psychological effects of THC include a sense of exhilaration, intense sensory experiences, talkativeness, increased cognitive abilities and altered time perception. Not to mention the increased appetite (munchies, anyone?). You’ve got to remember that there are too many factors at play when it comes to getting high. The same strain can cause hallucinations to some people and a pleasant head high to others.

Health Benefits and Risks from THC Use

Due to the illegal status of cannabis in many parts of the world, research regarding the effects of cannabinoids is inconclusive. We still don’t know much about the health benefits of marijuana, but then again, the same goes for its side-effects. However, there is some preliminary evidence to go around.

THC Medical Benefits

Marijuana cannabinoids have a lot of medical benefits on their own, and even more when they work in synergy. And although few people want to use THC-rich strains for medicinal reasons, it still has some uses as medicine!

Anti-Depressant

We wouldn’t recommend consuming high THC marijuana if you suffer from anxiety or insomnia. Although THC is mostly harmless, it is still psychoactive and can produce unpredictable side-effects. However, the euphoric cerebral effects of THC are great for people suffering from depression and negative thoughts.

Anti-Inflammatory

THC, like CBD, is a potent anti-inflammatory drug, suitable for autoimmune conditions or other causes of inflammation, like neurodegenerative disorders or multiple sclerosis.

Cancer

There is not conclusive evidence that THC can actually kill cancerous cells, however, there are certainly some promising early data. Cancer-killing or not, the use of THC in cancer patients can prove valuable, as it can improve the mood and reduce the symptoms of the harsh cancer treatments.

Pain

THC has great pain-relieving properties and can be a safe alternative to extremely potent and addictive opioids. With USA and Canada facing a mess of overflowing opioid medication that kills thousands each year, THC is a great solution.

THC works in a similar way to opioids, releasing dopamine that negates the pain signals sent to the brain.

THC Side Effects

Evidence for the long-term side-effects of cannabis is shaky at best, but then again, research is still ongoing. While marijuana is indeed beneficial, we believe it is best to take all of the hype with a healthy dose of skepticism and be realistic regarding our expectations from THC.

We won’t even discuss problems like lung cancer and bronchitis, as THC can be consumed in a myriad of ways that don’t involve smoking. So, let’s look at the purely medicinal claims about the harms of THC.

Permanent Brain Changes

Recent research has shown a correlation between frequent consumption of high-THC marijuana and alterations in a region of the brain called callosal commissure (which connects the brain hemispheres) and the hippocampus. Obtaining the data from cannabis users, researchers have found that people who consume high-potency THC, showed differences in the callosal commissure than people who don’t.

The good news is that these differences are not directly linked to any conditions, so we can’t reach any definite conclusions regarding their exact nature.

Memory Loss

A 2016 study suggested that frequent use of high-THC marijuana was associated with worse verbal memory and processing speed among 3385 participants. Specifically, the study claims that for every five years of continuous cannabis, the users’ verbal memory was 0.13 standardized units lower. In layman’s terms, that means 1 of 2 participants remembering 1 word fewer from a list of 15 words every five years.

Psychosis

People who are predisposed towards schizophrenia and other psychotic conditions have a reason to be cautious around THC. There is evidence that it can trigger the onset of symptoms earlier than expected. However, this can only happen to people who already have a genetic condition.

Recreational THC Use

Frankly, this is the primary reason we love THC: getting high and having a good time. In order to reap all the rewards of the highest THC strains, you need to find the perfect ratio for your needs. There is no use consuming an insanely potent strain only to find out that it makes you dizzy and paranoid.

Modern seedbanks are constantly trying to break records with selective breeding that promotes higher and higher concentrations of THC. In addition, the popularity of THC signaled the emergence of a new side-market: edibles, hash, concentrates, vape liquids and THC Oils are just some of the products you can use to get high without having to smoke. Sure, nothing compares to rolling an old-fashioned fat blunt, but methods like dabbing or vaping produce a more well-rounded and flavorful experience.

Top 10 Highest THC Strains

Marijuana strains are getting more potent each year, as seedbanks release their newest creations on the market. Below we will share with you our picks for the top 10 highest THC strains (under no particular order). It goes without saying that you should be careful around these, especially if your tolerance is low. Try a couple of tentative hits and see where that gets you. 

Gorilla Glue

THC Content: 24-30%

Apart from an actual glue brand, Gorilla Glue is also the accidental creation of two farmers Lonie Watie and Joesy Whales, as their Chem Sis plants turned out hermaphrodite, pollinating a Sour Dubb plant. This happy accident resulted in the creation of the Gorilla Glue strain!

With THC levels reaching 24-30%, this indica-dominant strain is among the most potent marijuana seeds available on the market. Legend has it the breeders chose to name it this way because the buds were incredibly sticky! This strain will flower about 10 weeks from seeding and will produce a respectable yield with enormous amounts of resin and THC!

Nova OG

THC Content: 32%

Nova OG is one of the most potent strains on the globe, having been tested with a whopping 32% content of THC. An indica-dominant strain with an immense flower production, the Nova OG offers an amazing sensory experience as well. The smell is rich and citrusy, while the taste is sweet and pungent. Grown outdoors Nova OG is will produce 650gr of flower per plant, while indoor yields will be around 500gr/m2.

Durban Cookies

 durban cookies

THC Content: 29%

A cross of two immensely powerful strains, Durban Cookies is obviously the mix between Durban Poison and Girl Scout Cookies. This sativa-dominant strain is extremely powerful and produces a clean and cerebral high.

Strawberry Banana

 THC Content: 20-26%

This tasty-named strain is an evenly balanced hybrid produced by the seedbank Reserva Privada. Strawberry Banana is a cross between Bubble Gum and Banana Kush and produces fruity and enjoyable taste. However, its smell is less than discreet, so if privacy is a concern, don’t use it in public! Testing labs have repeatedly found that Strawberry Banana strains produce THC levels between 20-26%. When grown indoors, this strain will flower in about 9 weeks, producing about 500gr of flower per square meter.

King Tut

THC Content: 25-30%

Named after the famed Tutankhamun, the Egyptian pharaoh of the 18th dynasty, King Tut is one of the most powerful sativa strains in the world. Its THC levels hover around 25-30% and its effects are full of speed and energy. Made my Pyramid Seeds (how apt!), King Tut is a cross between an AK-47 and an unknown strain. Due to its strength, beginners should tread lightly around this strain, lest they reap King Tut’s actual curse!

This strain is also quite fast, flowering within 8 weeks from seed. It grows quite short indoors, so you don’t have to worry too much about the size. It will produce about 500gr of flower per square meter.

Bruce Banner #3

THC Content: 30%

This strain takes its name from the timid scientist that becomes the superhero Hulk when exposed to Gamma Rays. We don’t know whether this strain was exposed to radioactive material, however, its 30%+ THC content surely is out of this world!

The taste is rich and citrusy, while the effects are creative and relaxing. This plant will grow quite tall and produce insane amounts of bud, even when grown indoors. Flowering times are between 8-9 weeks, while yields can reach 800gr/m2 indoors and 1000gr/plant outdoors.

Liberty Haze

Source: Barney’s Farms

THC Content: 25%

A cross between Chem Dawg 91 and G13, Liberty Haze is an even hybrid with a flowering time of about 8 weeks. The most notable feature of this plant (apart from its potency) is the fat, strong kolas that produce amazing yields both indoors and outdoors. The effects of smoking this are immediate and euphoric, while the taste is citrusy and pungent.

Godfather OG

godfather og

THC Content: 21-25%

Godfather OG is a popular strain with extremely relaxing properties. This strain is a cross between Bubba Kush, L.A Confidential and GDP. Powerful and pungent, this strain has the THC content to take you for a ride if you don’t approach it with caution!

Girl Scout Cookies

THC Content: 26%

Girl Scout Cookies is a strain with a long history, full of drama, hip-hop, and lawsuits. GSC (as it is also known) is one of the best strains to come out of Mendocino, CA. Suitable for indoor and outdoor cultivation, this plant will reach about 1m in height indoors, producing about 425-500gr/m2. However, if grown in warm climates (like California), this strain can reach almost 2 meters in height resulting in an impressive yield of 425-475gr/plant.

Venom OG Kush

Source: Herbal Solutions

THC Content: 19-23%

Venom OG is the creation of the breeders at Rare Dankness, who are also responsible for the Ghost Train Haze. This strain is a cross between their very own Rare Dankness #1 and Poison OG. The indica genetics are fairly obvious in this, as the buds are not too big and cluster together. Super easy for beginners to grow, this hybrid will grow to a medium size. Its indica genetics make it resistant to mold and disease. This plant will thrive in a warm outdoor environment!

About THC Measurements in Marijuana Strains

As we’ve seen in previous articles, the cannabis plant does not produce THC automatically. The production of THC is triggered when the non-psychoactive tetrahydrocannabinolic acid is heated in a process called decarboxylation.

As it is impossible to measure the actual THC, lab tests usually test for THCA and then use math to calculate an approximate THC content. THCA does not always convert to THC in the same ratio, so labs usually measure it as a percentage of the total weight.

However, even these calculations are often misleading: The equation used to determine the conversion uses a mass weight correction of 12%, which would only occur in a perfect vacuum. Therefore, there is no absolutely reliable way of finding out the actual THC content of a strain. So, if such info is available, take a look the THCA content of a strain, as it is usually a good indicator of how much THC the plant contains.