Cultivators tend prefer marijuana strains with high cannabinoid levels. Nowadays, the strongest selections are hybrid crosses of known strains which have "evolved" with the times to contain more and more THC over the decades.
So if you're looking for a serious high, what are the highest THC marijuana strains in the Seedstockers catalog? Here's our top picks for high THC content seeds.
What is THC?
First, let's start at the beginning. Of the more than 100 cannabinoids present in the cannabis plant, tetrahydrocannabinol (THC) is the primary cannabinoid responsible for the psychoactive effects of marijuana, with attributes that can range from altered perception to mood modification.
In 1946, Israeli chemist Raphael Mechoulam was the first to isolate from plant material and totally synthesize from scratch, THC. This marked the beginning of cannabis research that would lead to the discovery of many other cannabinoids, cannabinoid receptors and "endocannabinoids," the cannabinoid compounds our bodies naturally produce to trigger our immune system response and regulate our homeostatic balance (our overall state of optimal health, function and stability).
The most abundant cannabinoid found in buds or flowers of a mature cannabis plant, is tetrahydrocannabinolic acid (THCa). THC is not actually produced by the cannabis plant but is instead a byproduct of its age and degradation. Oxygen in the air, temperatures, and humidity all play an important roll in the conversion of THCa to THC over time. We attempt to delay this process as long as possible when we are properly conserving and storing cannabis.
When THCa comes in contact with high-temperatures – like that from the flame of a lighter – the process of conversion of THCa to THC happens almost instantaneously, the user inhales what is now THC, and this results in the effects we associate with smoking cannabis. Because of this, it is impossible to ingest THCa through inhalation; in order to consume THCa it must be ingested by eating.
Phytocannabinoids, like THC or THCa, interact with the endocannabinoid system in the same way that endocannabinoids such as anandamide do: they fit into cannabinoid receptors like a key in a lock and modulating the transmission of messages from one cell to another.
THC can trigger different biochemical responses that can include everything from dopamine release, resulting in feelings of relaxation, to a physical response, such as reduced inflammation or increased hunger. It also interacts with various regions of the brain, including the hippocampus (memory), frontal cortex (thinking and decision-making) and cerebellum (physical movement and coordination).
Girl Scout Cookies Auto
Ak420 Fem
Why does cannabis produce cannabinoids like THC?
Cannabinoids are known as secondary metabolites, which means that they are chemical substances produced by the plant that do not play a major role in its development, but are involved in the interactions between the plant and its environment. Therefore, the main hypothesis is that secondary metabolites act as an immune system of the plant, to defend itself against predators, parasites and pests.
However, they not only carry out these defensive tasks, but are also crucial for establishing communication and exerting effects on other plants or animals (e.g. to facilitate pollination or seed dispersal). In fact, it is theorized that THC also acts as protection from sunlight, acting as a screen that keeps the plant safe from excessive ultraviolet radiation. Cannabinoids are lipids – or fats. Hemp oil has an SPF of 6.
How is THC potency measured?
Cannabis potency refers to the amount of THC, expressed as a percentage by dry weight of the plant, present in marijuana. The THC content in different cannabis products (such as dried flower, an oil or a tincture) is also expressed in milligrams per gram (mg/g).
For example, if a variety has been analyzed at 18% THC then it can be said that the sample contained 180mg per gram of flower material. When joints or pipes and bong are used to smoke flower, there is a significant amount of loss of potency that comes from the destruction of cannabinoids from the high temperatures of combustion. Using a vaporizer device can significantly decrease the amount of THC lost in the process of consumption. Edibles are a better option still to make the most efficient use of potential THC potency.
It is impossible to have dried cannabis flowers with 100% THC. In fact, the capacity of flowers to contain cannabinoids tops out at about 30-35% total cannabinoids by weight. However marijuana concentrates made through extraction processes often contain from 50%-80% THC content. Distillates and isolates commonly reach above the 90% range. the potential THCa and THC content in dried cannabis flowers can vary from plant to plant, branch to branch, and even batch to batch of the exact same genetic or variety and can further vary depending on techniques and process for harvest, dry, and cure.
How to select THC potency
THC has a wide range of short-term effects that may or may not be experienced depending on the individual. We are all different, with a unique endocannabinoid system. Different people may feel quite different effects even when given the same amount of THC.
For example, while some may find that THC elicits strong feelings of calm and peace, others may notice an increase in their anxiety levels. The difference may be as simple as one's own body chemistry, but certain strains and varying concentrations of THC can also generate different results in how one feels.
With this in mind its clear that the effects of THC will be different for everyone. When choosing a strain, consider not only the THC potency, but also the method of consumption and dosage, along with personal factors such as age, gender or previous experience with cannabis. Remember to that THC potency is not the single indicator for how powerful the effects might be perceived. The synergistic effects between THC and terpene and terpenoid compounds in the flower, means that even lower potency THC flowers can hit harder than higher potency THC flowers – depending on the terpenes and terpenoids present.
The consumption of small amounts of THC can produce effects such as relaxation, greater happiness, excitement and creativity, more sociability and energy, and an increased appetite. However, consuming large amounts of THC can produce more overwhelming effects, which can become unpleasant for less experienced users, which can include feelings of tiredness, drowsiness, dry mouth, headaches, dizziness and impaired coordination.
The experienced cannabis user is usually more accustomed to the effects of THC than the occasional user, and is less likely to feel panic or anxiety after consuming a large amount.
Buy seeds with high THC content
Despite these side effects of THC, for some growers the high THC strains are the preferred strains to grow, as they provide the user with a stronger and more intense cerebral stimulation. However, answering the question of which strain has the most THC is a difficult exercise.
What potency do high THC seeds have?
For years, breeders have worked tirelessly to genetically modify plants with high THC content to produce offspring with the highest possible THC content to meet consumer demand.
In fact, THC concentration rates currently average around 16%-18%, whereas at the end of the last century, according to some studies, marijuana plants contained only 4% of this cannabinoid. The main reason is that every year the seed banks try to create more potent varieties so that their consumers can enjoy the grass to the maximum.
How much is high THC?
Weed with THC amounts above 15% might be labeled as strong. This said, cultivation and breeding techniques have evolved so far that weed testing between 20%-30% potential THC is becoming less and less rare. In fact, in legal regions such as Colorado, 29% potential THC flowers can be bought at almost any dispensary.
´It is rare to see THC levels above 25% in regions that have not taken steps towards legalizing the sale and production of cannabis. When we discuss potency percentages we have to remember that most of the cannabinoids found on flowers is going to be THCa, not THC. If an analytic report says that a sample has 26% THCa, 3% THC, and 2% CBD, for example, we can say that the flower tests at 31% total cannabinoids. The conversion of THCa to THC comes with a loss of molecular weight – what this means is that 26% THCa does not equate to 26% THC when smoked. Instead, 26% THCa means that there is a potential for 22.8% total THC, combined with the 3% already existing on the plant, this means that our 31% cannabinoid sample has a MAX potential of 25,8% THC – this is assuming perfectly efficient conversion, which of course will not happen in a joint.
Gelato 41 Fem
Does the quantity of THC determine the effect?
While THC is the primary driver of marijuana potency, it is important to understand the role that other cannabinoids (such as CBD, CBG, THCV, CBC or CBN) can play in enhancing and shaping the effect of a strain. The entourage effect is the name given to the synergy of several cannabinoids acting together to amplify the effects.
In addition to the entourage effect of other cannabinoids, the terpene profile is also believed to play an important role in modulating the type of effect we experience. This is why cannabis growers place so much emphasis on harvesting, drying and curing to obtain the richest terpene profiles.
Therefore, a cannabis strain rich in terpenes, THC and other cannabinoids often offers a more remarkable experience than a product that lacks the chemical diversity of all the compounds present in the plant.
Which seeds are high THC?
Obtaining the best cannabis seeds is also a key factor in achieving the highest THC levels and the best potency. However, it is important to note that without proper growing conditions, plants simply will not reach their full potential.
Results will depend on a variety of factors, including plant phenotype, grower experience and environmental climate, nutrient or lighting conditions. If you want the strongest cannabis possible, try growing some of our high THC seeds, either feminized or autoflowering seeds.
The best feminized seeds with high THC content
In the section of feminized seeds, among the strongest genetics with maximum THC values of our catalog you will find:
Wedding Cake Fem
Runtz Fem
One of the most special genetics from USA that comes from a cross between the powerful Gelato 33 and the famous Zkittle, to give rise to a indica dominant genetic with THC levels of 25% or higher in suitable growing conditions. The effect is incredibly strong, but very relaxing, so it is highly recommended for therapeutic uses, to combat insomnia or for a good evening of muscle relaxation. Excellent also to make concentrates.
Cookies Fast Fem.
For those who are impatient and want THC in abundance, Cookies Fast only needs 7 weeks to flower while maintaining its feminized photoperiodic qualities, so with the right vegetative period it can offer splendid harvests. Coming from the crossing of Cookies & Cream with the original Girl Scout Cookies, it is a fast version that can easily reach a potency of 20% THC, making it one of the most powerful varieties of the category 'Fast' of all the Seedstockers catalog.
Wedding Cake Fem
This is another wonder born from the union between a GSC (Girl Scout Cookies) and a selection of the spicy Cherry Pie, resulting in a hybrid that hits very hard with levels that can reach 25% THC, producing a fast effect with a dynamic and creative ascent to the cerebral level accompanied by a pleasant body relaxation. An ideal setting to calmly savor its fruity touches that merge with sweet and spicy notes; and a perfect choice for those seeking the highest possible potency levels.
The best high THC autoflowering seeds
In the autoflowering seeds section, we also have genetics that do not depend on photoperiod and offer THC levels comparable to their feminized sisters. As for example:
Sherbet Auto
The auto version of the famous and award-winning Sunset Sherbet comes with the guaranteed potency of the best genetics Made in USA of the moment, so you can expect THC levels of 20% or more combined with refreshing fruity flavors of mango or melon. And with a very fast effect that invades you from the beginning with an open and clear mind, very creative. Ideal for home growers looking for simplicity and above average yields.
Gorilla Glue Auto
One of the most sought-after, high-end autoflowering strains on the market. It comes from a three-way mix of Chem's Sister, Sour Dubb and Chocolate Diesel, resulting in a plant that only takes about 11 weeks before its ready to enjoy. You can expect the same euphoric high as the feminized Gorilla Glue, an effect that is brutal for its combination of active mind and relaxed body, which is ideal to enjoy lying on the couch.
OG Kush Auto
Probably the strongest autoflowering variety in the Seedstockers collection, with THC levels of 23%-24% and a genuine Kush flavor, intense and sweet, making it one of the best choices for growers of all levels. It takes only 75 days from seed to harvest, offering long lasting effects to rest body and mind after physical exercise or after a long day of work. It will help you to find sleep, as well as stimulating the appetite.
Seed varieties with high THC
Below, we also recommend other options in our catalog that move in different ranges of potency, so you can choose the one that best suits your needs or your tolerance to THC.
18-20% THC (High)
Santa Marta Haze Auto
A hybrid that combines the best qualities of the classic Amnesia Haze and Santa Marta, a magnificent Haze from the Colombian jungle, but now in a feminized autoflowering version that develops in only 11 weeks from seed to harvest. Its Sativa dominant genetics and THC levels create an intense psychedelic experience, slowly maturing to a more relaxed and introspective level. All seasoned with a fresh, earthy flavor that contains hints of pine and fruit; and XXL yields of assured quality.
Purple Punch Fem.
A genetics that comes from the union of Grandaddy Purple, famous for its high levels of THC, with Larry OG, which helps to add yield as well as strong flavor. One of the Top Made in USA strains with a fairly fast flowering time of only 8-9 weeks and can turn purple or reddish tones if the temperature drops slightly. And with a very powerful body effect that mixes with a euphoric and pronounced cerebral high, perfect for neutralizing stress or for the treatment of chronic pain.
21-23% THC (Very High)
BCN Critical XXL Fem.
A variety 'made in Barcelona' obtained after crossing clones of Kritikal Bilbo and Critical + (both from the Basque Country) with a Critical Mass, which results in a marijuana plant more productive than its parents and which exhibits hyper vigorous growth. It has a very fresh flavor largely dominated by citrus nuances that precede its strong effect of long duration, which largely relaxes the body and calms the troubled minds. It is not for nothing that it has become one of the most popular varieties from the Seedstockers catalogue.
Gelato Fast
Known on the American West Coast as Bacio Gelato, this is the fast daughter of the two much-loved Gelato 41 and Gelato 41 Auto versions. You can harvest her up to 2 weeks earlier than her feminized version and enjoy her delicious notes of ice cream and vanilla and chocolate cookies. Regular growers love it for its guaranteed potency and long lasting calming effects, which can be quite motivating. Like all Gelato, it is easy to grow, so you can't miss it.
24-28% THC (Extremely High)
OG Kush Fem
Undoubtedly, one of the one of the highest quality varieties of Seedstockers catalog. It comes from the cross between a Chem Dawg and a Lemon Thai Paki Kush, in the purest style of the OG genetics of the west coast of the United States, characterized by citrus aromas and an earthy and floral flavor. Its resinous buds produce a very strong effect, so it has become the great ally of medicinal users who need to relieve chronic pain, especially muscle pain. But if you are going to use it as recreational marijuana, its effect is open-minded and euphoric, with a very acceptable relaxation.
Cookies and Cream Fem
The genetics are born from Starfighter and a very potent phenotype of the Girl Scout Cookies family with the intention of getting the maximum % of THC possible, which makes this hybrid with indica dominance an ideal choice for resin extractions. It also offers really delicious aromas, with creamy and extremely exotic nuances. Undoubtedly a hybrid of excellent quality and potency, accompanied by a generous production, making it a highly recommended variety for both beginners and commercial growers.
+29% THC (Hyper Extremely High)
This category includes the varieties considered the most potent of Seedstockers and are recommended for consumers with some experience, as its effect can easily overwhelm newcomers.
Gorilla Glue Fem
One of the most loved American varieties, famous for its very high production of trichomes, which gives it a very sticky appearance that lives up to its name. It is a selection of Gorilla Glue, specifically the phenotype #4, born from a 3-way cross between Sour Dubb x Chem Sister x Chocolate Diesel. Its aroma is intense, mixing earthy nuances with sweet notes, in a combination as surprising as delicious. Its psychoactive power is enormous, mixing a strong sensation of cerebral psychedelia with an intense physical and mental relaxation, ideal for smoking at night and disconnect from the whole world.
Do Si Dos Fem
This is an American hybrid of enormous quality and delicious aroma, which is already in its own right one of the cult seeds of recent times. It is a cross between OG Kush Breath (a potent phenotype of GSC) and Face Off OG, which stands out for mixing a complex terpene range and for offering a very high psychoactive power, very cheerful and stimulating. It is also an excellent resin producer, which floods the plant with intoxicating aromas, mixing sweet and earthy notes with spicy and fuel touches.
Do Si Dos Fem
Now available in the USA 
