Our growers have tried and tested almost every cannabis strain there is and have handpicked their top 10 highest THC strains that will truly knock your socks off! Give them a go and let us know if you agree.

the top 10 highest thc strains 2021

THC otherwise known as tetrahydrocannabinol is the chemical compound found in marijuana that produces its psychological effects. It works by stimulating the brain to release hormones such as dopamine, which is often referred to as ‘the happy hormone’. By releasing these hormones users start to feel the euphoric high that cannabis is best known for.

After the stresses of everyday life sometimes you need something a little stronger to relax with. That’s why our professional team of growers have compiled a list of ten of the top high THC strains that money can buy. Users beware, these cannabis strains are not not for the faint hearted and should be reserved for seasoned smokers only!

what strain has the highest percentage of thc?

A common question that is often debated among friends and cannabis connoisseurs is ‘who has smoked the strongest weed?’ According to recent lab tests here are the top 5 highest THC strain tested:

  1. Gorilla Glue – 32% 
  2. THC Bomb – 32% 
  3. Bruce Banner – 31%
  4. Girl Scout Cookies – 28%
  5. Banana Kush – 27%

Gorilla Glue aka GG#4

Highest THC strains
Yield
500 - 600 g/m2
THC
25 - 32%
Flowering Time
8 - 10 weeks
CBD
<1%
Height
180 - 200 cm
  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Our list of the highest THC strains would not be complete without the world famous Gorilla Glue. Also known as GG#4 this knockout cannabis strain was aptly named after the famous super glue brand ‘Gorilla Glue’, because when the breeders harvested the plant, it was said that there was so much of the sticky resin that it stuck your scissors and fingers together like glue.

Gorilla Glue has won numerous awards since it was introduced in 2014, including 1st Place at the 2014 Cannabis Cup in LA and Michigan and more recently 1st Place at the 2018 Spannabis Cannabis Championship Cup.

Gorilla Glue is most well known for its super high potency and has been lab recorded at 32% THC multiple times, it is arguably the strongest cannabis strain in the world.

Training techniques: Gorilla Glue works well with most plant training techniques, although a trick to produce bigger yields and the highest THC levels is Supercropping. this is because the stress inflicted on the plant often causes the plant to increase nutrient uptake and increase trichome production. Gorilla Glue being a trichome rich plant works wonders with Supercropping. Read more on how to train your cannabis plants

Gorilla Glue #4 is a 50:50 hybrid, the plant will grow to around 200cm tall and have a dense foliage for dark green leaves spattered with white crystals. The buds grow thick and solid and will be heavily clustered spread over multiple main bud sites and the buds themselves will be a vibrant green colour with purple hues. The buds are so sticky and trichome rich that just simply breaking one open will fill a room with GG4’s famous musky, earthy, sweet aromas that will have you reaching for the rolling papers in an instant.

Gorilla Glue #4 is widely known as one of the strongest, if not the highest thc strain on the planet, with lab tested percentages up to 32%. The strain is not for the faint hearted and will give you one of the most intense highs you are likely to experience. When you smoke Gorilla Glue you will almost immediately be hit by its heavy full body buzz that will inevitably lead to couch lock. Gorilla Glue is a very intense high so is probably best suited to smoking in the evening when you can relax or simply if you have a day off work. Medicinally many users have reported that it is a great strain to combat stress or depression thanks to its intense euphoric highs, but equally it can be used as a natural pain relief or muscle relaxant.

Gorilla Glue thanks to its trichome covered buds gives off an incredibly strong aroma of diesel with notes of coffee and earthiness. The taste is a strong skunky taste with undertones of citrus fruits and earthiness.

Gorilla Glue is a 50:50 hybrid cross of Sour Diesel, Sour Dubb, Chem Sister and Choc Diesel.

Zkittlez

Highest THC strains Zkittlez
Yield
400 - 500g/m2
THC
Up to 25%
Flowering Time
7 - 8 weeks
CBD
1 - 2%
Height
100 - 180 cm
  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Zkittlez was introduced to the cannabis scene in 2015 and won the Best Indica category at the in its first year at the 2015 High Times Cannabis Cup in Michigan. Named after the fruity sweets ‘Skittles’. Zkittles is not only a great tasting strain, but is also highly potent too with over 25% THC. Zkittles is also very visually appealing with its vibrant coloured buds that certainly give it a degree of bag appeal.

Not the highest THC strain on our list, Zkittlez has been lab tested at over 25% THC which is still not something to be scoffed at. For growers that enjoy a sweet fruity tasting cannabis strain that will also send you to sleep at night you cannot go wrong with Zkittlez.

Zkittles is a truly beautiful strain that really does live up to its reputation. The plant is a vibrant emerald green colour with large solid buds and various shades of green and purple clustered with orange pistols. 

Zkittles is an indica dominant strain that reaches around 100 – 180cm in height. She is a compact plant with a healthy, dense foliage consisting of your typical large indica fan leaves. Zkittlez is a versatile strain that can be grown both indoors and outdoors. Its short to medium height makes it a great strain to grow in a tent using techniques such as LST to increase its already large yield (500 g/m2).

Zkittles is both high in THC with percentages of up to 25% and also decent yields of around 500g/m2 making it a perfect strain for cash croppers looking for a potent plant to grow.

Zkittles gives its users a vivid cerebral high that will make you feel as though time has slowed down. This leads into a feeling of utter euphoria developing more into an indica body stone that will have you feeling relaxed and out for the count.

Zkittles is a perfect strain for smoking after a stressful week at work when you just want to relax in the evening and let the time pass by.

Despite its indica dominance, Zkittles is known to be one of the best strains for lifting your mood making it great for treating depression or anxiety.

Zkittlez bold and vibrant colours are just as impressive as its taste and aroma. When you finally break open one of your long-awaited buds, you will get strong aromas of citrus that almost smell like fresh lemon zest mixed with the sweet smell of summer berries.

The taste of Zkittles cannot be rivalled by many other strains. It is an incredibly smooth smoke with a fresh citrusy taste and sweet tones of tropical fruits.

Zkittlez is a 70:40 sativa dominant hybrid cross of Grape Ape and Grapefruit crossed with another undisclosed strain.

THC Bomb

Highest THC strains THC Bomb
Yield
500 - 600 g/m2
THC
Up to 32%
Flowering Time
8 - 10 weeks
CBD
1%
Height
100 - 180 cm

Recommended shops & prices (10 seeds):

  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

THC Bomb feminised was the first ever strain produced by the well-known Dutch breeder Bomb Seeds. This super high THC strain was recently lab tested and came back at over 32% THC, which is even higher than is stated by MSNL or the Breeder. The true potential of this strain is still to be discovered by the wider cannabis community but if you are feeling adventurous and want to grow something that not so many other growers will have then THC Bomb is the strain to grow.

THC Bomb is an indica dominant hybrid that will grow short and squat with the average height reaching 100-180cm. It will grow in a typical Christmas tree style shape, with a thick foliage that is clustered with dense solid buds. You can expect impressive yields from this strain of up to 600g/m2, which is astounding for a strain that has such high THC levels.

Because of its short stature, THC Bomb is a great strain for growing indoors. I have seen great results when using the ScrOG method combined with some defoliation to manipulate its shape and really take advantage of the bushy plant. If you are looking for a strain that has both knockout THC levels and big yields, then THC Bomb is the perfect strain.

THC Bomb is a super powerful indica dominant strain that will leave you feeling relaxed and at time couch locked. The first smoke of this strain will give you a rush of euphoria that will gradually slip into a heavy full body indica stone. Like all high THC strains users have reported dry mount so keep a drink nearby to quench your thirst.

Because of the indica heavy high from THC Bomb, it is a great strain to smoke at night time to combat insomnia.

THC Bomb has a sweet earthy aroma with hints of citrus fruits. The taste is earthy with sweet undertones reminiscent of tropical fruits.

Bomb Seeds keep the genetics of their flagship strain a mystery, what we do know is that it is a knockout mix of their Bomb #1 and an unknown indica.

Bruce Banner

highest thc strains Bruce Banner
Yield
500 - 600 g/m2
THC
Up to 32%
Flowering Time
8 - 10 weeks
CBD
<1%
Height
180 - 200cm

Recommended shops & prices (10 seeds):

  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Named after the marvel comic book character Bruce Banner, the cannabis strain is more like his angry alter ego, 'The Incredible Hulk'. At an impressive 30% plus the THC levels of Bruce Banner are not to be taken lightly. Unlike most high THC strains Bruce Banner is a Sativa dominant hybrid that will leave you feeling uplifted but still hazy.

Bruce Banner won the High Times Cannabis Cup in 2013 and at the time the sample was tested at 28.35% THC which made it the highest THC strain ever to be tested in the history of the High Times Cannabis Cup. Renowned for being one of the highest THC marijuana strains in existence Bruce Banner #3 is a must try for any cannabis connoisseurs that enjoy strong weed. 

Bruce Banner #3 thanks to its sativa heritage is a tall plant that has been known to display three main phenotypes, all three with incredibly high THC percentages.

Physically Bruce Banner is a stunning plant to look at. In flowering the plant develops bold green leaves with vibrant colored buds covered in orange and brown pistols. Towards the end of flowering the buds will be completely covered in trichomes that make the plant glisten and incredibly sticky to the touch.

This is where Bruce Banner really comes into its own. It is likely that you wont have ever smoked anything as strong as Bruce Banner before so go easy on your first smoke. On your first inhale you will experience a big hit that will make your head feel hazy and slightly stunned, some have experienced such relaxedness that they cannot even think for the first few seconds. This gradually leads into a feeling of utter euphoria as the body numbing buzz hits you. Thanks to its sativa genetics you will find that despite its high THC percentage, Bruce Banner does not give you the couch locked feeling that most high THC strains give. But instead gives you a more creative and sociable high perfect for a strain to kickstart the day with.

Bruce Banner #3 smells incredibly pungent from the moment the plant begins to develop flowers. The smells will be strong skunky aromas typical of cannabis plants but also with undertones of candy and citrus fruits. As you dry the bud Bruce Banner will begin to develop more floral notes and only when you have fully cured it can the full depth of smell be truly appreciated.

It is advisable to use a good carbon filter when growing this strain due to the strong odor the plant is known to produce.

The flavours of Bruce Banner #3 are even more appealing than the smell, as the crackle of your first smoke is inhaled you mouth will be filled with flavours of citrus fruits with a sweet candylike aftertaste that is reminiscent of a hot summers day.

Bruce Banner #3 is a hybrid strain but with 60% Sativa dominance bred from OG Kush and Strawberry Diesel. The two parent strains blended together to create the perfect combination of a high THC strain that is a great smoke.

Do Si Dos

Highest THC strains Dos Si Dos
Yield
400 - 500 g/m2
THC
25% +
Flowering Time
8 - 10 weeks
CBD
1%
Height
100 - 180 cm

Recommended shops & prices (10 seeds):

  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Dos Si Dos is an indica dominant hybrid strain, that is bred from the well-known Girl Scout Cookies lineage crossed with Face Off OG to give you a truly remarkable plant. With THC percentages recorded at well over 25% THC, Do Si Dos is a cannabis strain that will give you a full blown heavy indica stone. 

Growers that enjoy a relaxed high will love Do-Si-Dos. Being an Indica dominant strain she stays relatively short so is an ideal strain to LST.

Dos Si Dos will grow to a medium height of 100 – 180cm keeping true to its bushy indica shape. If you want to grow a strain that is beautiful and still has a knockout punch then Dos Si Dos is the strain for you. She will grow into a dense plant with bright lime green coloured leaves interspersed with solid dense buds. The buds are speckled with orange hairs and have a bluish-purple hue to them that tends to darken as the plant nears the end of its harvest.

The high from Dos Si Dos is unmistakably indica dominant. The first inhale will give users a buzzy uplifting high and with more smoking it will gradually lead into a heavy sedative stone that will leave you feeling numb. Despite the sedative effect the high from Dos Si Dos is remarkably uplifting which makes it an excellent strain to combat stress, depression, or anxiety. It truly will leave you feeling like you have not got a care in the world.

The aroma of Dos Si Dos is pungent and skunky with powerful citrusy tones. Around halfway through the flowering stage the plant will begin to give off a powerful floral odour that is unmistakable. Stealth growers be aware, make sure you have a carbon filter fitted by this point!

Dos Si Dos is an Indica dominant hybrid cross of OG Kush Breath & Face Off OG.

Northern Lights #5 x Haze

Northern Lights #5 x Haze cannabis seeds review
Yield
600 - 700 g/m2
THC
22 - 25%
Flowering Time
10 - 12 weeks
CBD
1 %
Height
180 - 220 cm

Recommended shops & prices (10 seeds):

  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Northern Lights #5 x Haze has won multiple cannabis awards over the years including the High Life Cup and has truly cemented its status as a legendary strain. Bred by Sensi Seeds by crossing Northern Lights with a sativa dominant haze this plant is both a high yielding high THC monster of a plant with lab reports of over 25% THC. 

Sensi Seeds is the oldest cannabis seed bank in the world, steeped in history. They are renowned for producing some of the best cannabis in the world and have a reputation as being the original cannabis breeders.  

Northern Lights #5 x Haze is 70% sativa which becomes evident once the plant reaches the middle of its vegetative stage of growth at which point the plant has a sudden growth spurt and can almost double in height. Because her height can reach up to 300cm it is the perfect strain to grow outdoors, or alternatively if you are growing indoors prepare to do some plant training to taper its shape. Long swathes of bud will fill the gaps between the foliage and if grown outdoors the yields are immense.

If you want a strain that is high in THC but also uplifting and can be smoked during the daytime then Northern Lights #5 x Haze is the perfect smoke for you. As soon as you inhale the smoke flavours of Northern Lights #5 x Haze you will get an instant full body buzz that will leave you feeling happy and euphoric with a sense of creativity.

Northern Lights #5 x Haze produces a distinctive spicy aroma while growing that becomes ever more prominent the further the plant goes into flowering. When you smoke Northern Lights #5 x Haze the typical citrus flavour of sativas come through with undertones of pine and earthiness.

Northern Lights #5 x Haze is a 70:30 indica dominant cross of the famous Northern Lights and a Haze strain.

Gelato

MSNL Seed Bank Gelato
Yield
500 - 600 g/m2
THC
25 %
Flowering Time
8 - 10 weeks
CBD
1 %
Height
120 - 180 cm

Recommended shops & prices (10 seeds):

  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Gelato also known as ‘Larry Bird’ is a super potent hybrid mix of two of California's most popular strains, Girl Scout Cookies Thin Mint and Sunset Sherbet, the result is something truly remarkable. This THC powerhouse has been recorded to have percentages of up to 26% which is enough to send even the most seasoned smokers into a deep sleep.

For growers who want a super high THC strain that is also great tasting Gelato is not one to be missed. Developed in San Francisco from a cross of Sunset Sherbet and Girl Scout Cookies Thin Mint Gelato has almost no CBD.

Gelato Plants are distinctive in appearance thanks to their vibrant emerald, green colour. When in the flowering stage of growth, they will develop a thick foliage that is clustered with fluffy buds. The buds will be light green in colour with purple hues and orange pistols that will gradually turn to a dark bronze as the plant nears its harvest. As you harvest the plant you will see that the buds will be almost white where they are so heavily covered with glistening trichomes.

Smoking Gelato is intense to say the least. Go easy on the initial inhales because the high creeps up on you and can lead to a couch lock eventually. At first you will feel a cerebral buzz with a sense of euphoria that with more smoking will lead into a sedative calm.

Many users that smoke gelato report it to be an effective strain to combat aches and pains.

The taste from Gelato is a distinctive sharp citrus fruit flavour with undertones of sweet forest berries which is where the strain got its name ‘Gelato’. 

As Gelato grows you will get aromas of pine when the plant is coming into its flowering stage with hints of lavender as the plant matures.

Gelato is an Indica dominant hybrid strain that was developed in San Francisco from a cross of two other high THC strains, Girl Scout Cookies Thin Mint and Sunset Sherbet.

Girl Scout Cookies

Girl Scout Cookies cannabis bud
Yield
400 - 500g/m2
THC
Up to 28%
Flowering Time
8 - 10 weeks
CBD
1%
Height
100 - 180 cm
  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Girl Scout Cookies (also known as GSC) is a super potent Californian strain the was created in 2010/2011. The strain is a cross of two popular strains; Durban Poison and OG Kush combining the best traits of both indica and sativa. 

Girl Scout Cookies is also known as Berner Cookies because the strain was supposedly created by rapper, Berner (otherwise known as Gilbert Millam Jr.). 

Since its creation Girl Scout Cookies has become something of a legend and is now one of the most smoked strains around the world. She is a very high THC strain only just behind the likes of Gorilla Glue coming in at 28% THC.

Girl Scout Cookies is not a strain for huge yields, but it more than makes up for this with its sweet tasting highly potent buds. 

When you grow Girl Scout Cookies you will see that the strain is a perfect mix of sativa and indica. She will grow an average height of around 180cm making it an easily manageable strain to grow indoors. One of the benefits to growing Girls Scout Cookies is its natural ability to pest and mold resistance. 

Girl Scout Cookies is a beautiful strain to look at and when in full flower you will see the bright green buds surrounded by purple leaves and vibrant orange pistols. 

As a cannabis connoisseur Girl Scout Cookies is a strain that I believe everyone should try. It is a perfect mix of uplifting sativa buzz combined with a relaxing sedative effect that will lead you into a deep sleep. The initial inhale will give you an intense cerebral rush followed by a more mellow full body indica stone.

Because of its uplifting and yet relaxing effect on the body Girl Scout Cookies is a great strain for those suffering with depression or stress. One puff on this and you will feel like you really don't have a care in the world.

Possibly the most impressive aspect of Girl Scout Cookies is the taste and smell of the buds. When you break open a freshly harvested bud your nostrils will quickly fill with the sweet smell of fruits with light earthy undertones. 

The taste of Girl Scout Cookies is even better than the smell. As you light up your first sampling of this strain you will get a sweet smell, not too dissimilar to freshly baked cookies. On the first inhale you will get a sweet sugary flavour with hints of cinnamon and citrus fruits. The perfect smoke to end a long day with.

Girl Scout Cookies is a hybrid mix of OG Kush and Durban Poison.

Banana Kush

MSNL Seed Bank Banana Kush
Yield
600 - 700 g/m2
THC
Up to 27%
Flowering Time
8 - 10 weeks
CBD
>1%
Height
100 - 150cm

Recommended shops & prices (10 seeds):

  • Overview
  • Appearance
  • Effect
  • Taste & Smell
  • Genetics

Banana Kush is yet another Californian strain that is an indica dominant hybrid cross of Ghost OG and Skunk Haze. The result is a potent high THC  mix of both sativa and indica that gives you an unforgettable high. THC content can vary depending on how it is grown and where it is purchased. A recent lab report came in at at an impressive 27% THC, however Banana Kush is a relatively new strain to the cannabis industry so its full potential may still be to come. 

As expected from an indica dominant strain Banana Kush stays short and busy with compact buds. As the plant reaches the middle of its veg cycle you will see a huge increase in the large fan leaves and gradually you will see the bud sites begin to develop. The plant is a deep green colour with dense buds that have a yellow hue to them. As the plants buds develop you will see one large central cola that forms. If you train this plant properly using LST or ScrOG you will see multiple large bud sites and a big increase in yields.

The smoke of Banana Kush is intense with an initial heavy body stone, clearly from the indica heritage. This is balanced out nicely though and thanks to its haze genetics you will feel uplifted nut super chilled. Banana Kush is a strain that should definitely be reserved for night time use and thanks to its heavy indica high it is a great strain for relaxation or anyone suffering with insomnia.

As would be expected, when Banana Kush nears harvest you will get the typical earthy scent from the strain but the prevalence of Banana is definitely there. The smoke is incredibly smooth with a spicy earthiness to it and a hint of sweet banana undertones.

Banana Kush is a 60:40 indica dominant cross of OG Kush and a Banana father strain.

how to increase thc when growing weed

THC is the compound within cannabis that gives us the psychoactive effect when its smoked, in other words, it gets you high. Many regular weed smokers will have noticed an increase in tolerance to THC over time, the more often you smoke the more it takes to get you get you high. If this is you then growing high THC strains and learning how to increase its THC percentages is exactly what you need to know.

There are five factors that will affect the levels of THC found in the cannabis you grow, they are:

Strain genetics

Starting with the right genetics is the most important factor in determining how much THC your weed will contain. Lets say you choose a strain that can produce 22% THC, this number is the upper limit of how much THC this particular strain is capable of producing under ideal conditions. How well you grow the plant is also a determining factor of THC percentage, so you could end up a lot less than 22% THC if everything doesn’t go completely to plan. Growing a strain such as Gorilla Glue or Bruce Banner that is genetically inclined to produce potent bud, will give you the best chance of producing super high THC weed. To put it simply, if you want to smoke high THC weed, then you should first look to grow using high THC strains. Buying a strain from our list above would be a good start.

Time your harvests to perfection  for high thc strains

During the flowering stage cannabis plants usually have a 2-3 week window when the bud is at its most potent, if you are growing the highest THC strains you should aim to harvest within this window. As the plant matures and comes towards the end of its flowering stage you should periodically asses the trichomes using a magnifying glass or jewellers loupe. When the trichomes become milky white in colour and around 70-90% of the pistols have turned dark and began to curl in, this is when the weed is at its most potent and should be harvested for optimum THC levels. Learn how to time your harvests to perfection.

Good plant health = high thc marijuana

If you want to produce high THC marijuana then you need to ensure that your plants are happy and healthy. This means controlling your grow room climate and avoiding those common mistakes such as over and under watering, nutrient burn, mold and bud rot, heat stress and plant pests. The more your plant is able to focus on growing and developing, the better the quality of bud will be and the higher its THC will be.

Give your plants enough of the right type of light

Light is like food for cannabis plants, without enough good quality high intensity light cannabis plants will not grow to their full potential. During the flowering stage cannabis plants use light to power the growth of buds so it is important to make sure that they are getting the right type of light and the right intensity during this period. If you want to grow good high THC, high yielding strains you need to use high intensity lights such as LED or HID bulbs to grow them.

Outdoors you wont have as much control over how much light a plant gets. But timing your grows will have a big impact on both the yield and THC levels of a plant. For example, planting your seeds in March – May will give you plenty of daylight during the flowering phase of growth. Plant them in July or August and it may be too late to get the full potential from the plant as summer draws in.

Cure your weed correctly

Once you have harvested and dried your buds, to improve the flavour and potency it is important to burp and cure them. The most common method of doing this is curing buds in jars, to do this you simply store them in a jar or container for a couple of weeks, periodically shaking them and opening the jar to burp them.

Although there is little evidence that shows this process increase THC levels, it does improve the  perceived potency of the bud, as well as the taste and smell.

you may also be interested in ....