Looking for one of the strongest weed strains to challenge your tolerance or ease stubborn medical symptoms? A strain’s potency depends on a mix of factors—including how it was grown, its genetic lineage, and more—but we’re here to highlight some of the most popular strong weed strains of 2025 that consistently bring the heat.
While THC is the main driver of potency, it’s important to understand how terpenes can enhance and shape a strain’s high. Aromatic compounds like myrcene, caryophyllene, and limonene not only give cannabis its distinctive aroma, but when paired with high THC, they can deliver a more powerful and well-rounded experience.
The strongest weed strains below are just a sampling of today’s most buzzed-about heavy-hitters. Whether you’re after euphoria, deep relaxation, or both, remember the classic advice: start low and go slow.
Permanent Marker

Leafly Strain of the Year 2023 Permanent Marker combines looks, gobs of smell and taste, with an undeniable roundhouse to the cranium high. Hey, it’s what we seek after a long day of fighting down Highway 101, trying to escape The Valley. Seed Junky Genetics of LA also made Wedding Cake and only does super-strong strains. No Dad Weed here, sorry. People get tingly, talkative, and aroused on this party favorite—it’s hard to go wrong with it this 4/20. Just drink lots of water and pace yourself out there.
GMO Cookies

GMO is our Leafly HighLight of April 2024 and a go-to face-kicker if that’s your sort of thing. It can smell funky and skunky, your limbic system goes on high alert for a poison or noxious chemical. But ewww it stinks so good—for sure an acquired taste. Read all about GMO in the HighLight.
Motorbreath

Motoring along onto a ton of menus without too much hype—Motorbreath is smoking them with a 26%+ THC score, on average. This might be more bike than you can handle. It’s Chemdog and SFV OG, both of which can get you cooked. Users report diesel, pepper, chemical smells, and side effects may include an anxious dizziness and The Fear. Alas, some of us like to ride shotgun with our old friend Fear, just to feel a little alive, I guess. Snowtill No-Till Living Soil in San Francisco has the Motorbreath dialed.
Runtz

There’s no way you get to Leafly Strain of the Year 2020 without getting people faded. The Runtz crew out of Long Beach, CA promised as much as delivered with this Gelato-based strain. Accept no watered-down fake Runtz. Ask to smell the bag and look for those sweet, treefruit berry notes.
Khalifa Kush

Get at this refined type of OG Kush for that KK-level high. Rapper Whiz Khalifa’s brand is like 90% THC, so their flower has to hit. It’s testing at 21% on average, with a lemon-pine-fuel smell and taste.
Kush Mints

Primary terpenes:Limonene, caryophyllene, linalool
Average THC: 27%
Combining old school classic Bubba Kush, and energetic Animal mints, Kush Mints is a THC powerhouse. This strain has increased in popularity as of late, likely due to its potency and complex minty flavor profile. If you’re a cookies lover looking for something a little different, check out Kush Mints.
Ice Cream Cake

Ice Cream Cake taps into the Cookies and Cakes craze in weed of the last few years, crossing Wedding Cake—Leafly’s 2019 strain of the year—and Gelato #33, a phenotype of our 2018 strain of the year. ICC is a relaxing, sleepy strain that’s great for nighttime. It’s sweet, creamy flavor profile makes it accessible to a broad range of smokers, just be sure to have a soft couch and some munchies close by.
MAC (Miracle Alien Cookies)

Short for “Miracle Alien Cookies,” MAC has some Cookies and Chemdog buried in its roots, giving it a complex flavor. MAC is a strong, uplifting strain with a smooth orange flavor and floral notes. It’s so popular, related phenotype MAC 1 is also out there, which is usually slightly less potent and more balanced in effects.
Bruce Banner

Bruce Banner, appropriately named after the Hulk’s alter ego, is a heavy duty hybrid with a staggering THC content. Powered by OG Kush and Strawberry Diesel genetics, Bruce Banner delivers a dizzying punch of euphoria that anchors your body in deep relaxation.
Original Glue

Original Glue, also known as “GG4” or “Gorilla Glue,” is named for the stickiness of its resinous buds, and this strain certainly lives up to its name. Multiple Cannabis Cup awards back up the legend of Original Glue’s potency, but we doubt you’ll need the proof once you’re stuck to the couch in stupefied contentment.
More high-THC weed strains
Looking for more strains? Check out these heavy-hitters.