What is actually in a cartridge
Cannabis extract is stripped down to a thick, clear oil that is mostly THC. Something is added back to give it flavour and to make it thin enough to wick. That mixture sits in a tank with a heating element, a wick or a ceramic core, and a threaded connector that screws onto a battery.
Almost everything that goes wrong with cartridges goes wrong in the second step or in the hardware, and almost nothing on the packaging describes either.
Distillate is nearly flavourless
Refining extract to a high THC figure strips out most of what gave the plant its smell. The result is potent and close to tasteless, which is why it has to have flavour put back. A cartridge that tastes strongly of anything is telling you something was added; the question is what.
Where the terpenes come from
- Cannabis-derived, recaptured from the same plant material. Closest to the original, most expensive, hardest to find stated plainly.
- Botanical, the same molecules sourced from other plants. Chemically real terpenes, arranged by a flavourist rather than by the plant.
- Flavourings that are neither, which is where the food-industry compounds no one has studied in an inhaled form come in.
Cutting agents and the outbreak
Thinning agents make a thick oil flow through a wick, and they are the cheapest way to make a gram go further. Several have been used over the years. One of them killed people.
What EVALI actually showed
As of February 2020 the CDC had recorded 2,807 hospitalised EVALI cases or deaths and confirmed 68 deaths across 29 states and the District of Columbia. Vitamin E acetate, used as a thickening and cutting agent, was found in the lung fluid of 48 of the 51 patients tested and in none of the healthy comparison group.
Where the products came from
This is the part that gets left out. Among hospitalised patients with data, 82 per cent reported using a THC-containing product and 33 per cent reported using nothing but THC products. Of those who named a source, 78 per cent had used only informal sources — friends, family, dealers, online sellers — against 16 per cent who had used only commercial ones.
The outbreak was not really a story about vaping. It was a story about an unregulated supply chain adding a cheap thickener that nobody tested in a lung.
The certificate, line by line
| On the certificate | What you are checking |
|---|---|
| Batch or lot number | That it matches the number on the box in your hand |
| Date of analysis | Recent, and after the batch was made |
| Laboratory name | A third party, not the brand |
| Cannabinoid profile | Numbers, not a range or a marketing figure |
| Residual solvents | Tested, with a pass against a stated limit |
| Pesticides | Tested, and the panel named |
| Heavy metals | Tested — this one is about the hardware |
What the batch number is for
A certificate that does not carry the batch number on the package is a document about some other cartridge. This single check disposes of most counterfeits, because faking a plausible certificate is easy and keeping a per-batch one matched to a package is not.
Potency is the least useful number
The percentage tells you how concentrated the oil is, not how much you will take in, not how it will taste and not whether it is clean. It is also the number most commonly inflated, because it is the number buyers compare. Our page on what a THC percentage means goes into why.
Pesticides and residual solvent
Concentrating a plant concentrates whatever was on it. Extraction adds a second problem, which is the solvent used to do the extracting and how much of it is left behind. Both are testable and both are on a real certificate.
What 80 per cent contaminated meant
Raber, Elzinga and Kaplan analysed 57 concentrate samples from the Californian medical market and reported that over 80 per cent were contaminated in some form, with residual solvents and pesticide residues the main findings. That was a legal, licensed market being sampled, which is the point: testing is what makes the difference, not legality alone.
Hardware matters more than the oil
The tank, the wick and the heating element decide whether the oil arrives as vapour or as combustion products. Cheap hardware is also where heavy metals come from, leaching out of solder and poor-quality alloys into the oil sitting against them.
Ceramic, wick and the burnt taste
A wick has to stay wet. When the oil is too thick, or the coil too hot, or the tank too empty, the wick dries and what you inhale is a scorched wick. That harsh taste is not a strong cartridge; it is a cartridge being burnt, and it is the commonest complaint about cheap ones.
Voltage, and why lower is better
Most 510 batteries offer a few settings. Lower settings produce less vapour and better flavour; higher settings produce more vapour, more degradation of the terpenes and more of the burnt note above. Starting low and going up is the correct order and almost nobody does it.
How to spot a counterfeit
- Packaging with no batch number, or a batch number that matches no certificate.
- A QR code that leads to a brand page rather than to a specific batch report.
- Branding that is very slightly off — a font, a colour, a registered mark in the wrong place.
- An implausible price for a full gram.
- Any purchase not made from a licensed retailer, which is the one that matters most.
Storage, leaks and upright
Heat thins the oil and makes it leak past the seals; cold thickens it and makes the wick struggle. Upright, at room temperature, out of the light and out of a hot car covers nearly all of it.
A full gram is not a bargain
A gram cartridge that costs little more than a half-gram is either a smaller gram than it says or a thinner oil than it should be. The maths on that has been the tell for years and was the tell during the outbreak too.
Why we are not naming brands
This page used to carry nine product cards. They were Californian dispensary brands listed in 2019, with no tested specification against any of them and no working link, and several of the businesses no longer exist. A list like that is worse than no list, so it is gone. When there is something tested to recommend, it will appear here with the testing attached.
Where to buy, and from whom
A licensed retailer in a legal market, with a batch certificate you can match to the package. That is the whole recommendation, and the outbreak numbers above are the argument for it. For what is on the shelf near you and what it costs, that is BudFinders rather than this site.
The products this page covers
Carried across from the earlier version of this page so the formats can be compared side by side. These are not recommendations: we have not tested them, and the details on each need checking against current listings before anyone acts on them.
Pax Era Pods Bloom Farms
Bloom Farms produces both, best THC cartridges for conventional vape pens with a 510 connection and PAX Era Pods line. Both contain Bloom Farms’ special blend of all-natural cannabis oil, extracted through a solvent and petroleum-free CO2 extraction process. There’s also the Sherbet live resin PAX pod. Due to its ease and vapor production, we prefer the Bloom Farms Era pods, these top quality pods are designed specifically for use with the popular PAX Era vaporizer.
THC and CBD levels are labeled on each product, with the average THC percentage testing between 60 and 90 percent. You’ll enjoy the taste as well. The carts are primarily sold in licensed dispensaries in California and Nevada. You can also get them delivered from Eaze
STIIIZY Vaporizers
STIIIZY Vapes are another top contender for our favorite vape carts. They offer an awesome discreet device and their own line of premium pods. Its very similar design to the pax era but I like the STIIIZY mouthpieces a little better. The battery also runs great on these devices and continues to get the job done. As far as the carts go they offer a great selection of strains that they cultivate, hand select and name all in house. all extraction is done in house in STIIIZY state of the art labs selecting only the most excellent flower to make excellent extracts.
You can find STIIIZY products in one of STIIIZYs 16 retail stores across California. STIIIZY products can also be found in Arizona, Nevada, Michigan, and Washington, and California.
Select Elite Cannabis Oil Cartridges
Select Elite cartridge oils are made using a proprietary, highly-refined distillation technique that results in a full spectrum cannabis oil of 75-95% THC. In their line, organic cotton wicks are used to preserve the great flavor of the distillate so the taste will last. That means the terpenes are strong and good as well.So if you love your terpenes, this is a great choice including the full spectrum goodness. Then there’s the ceramic core technology. Ceramic core ensures an even temperature for smooth puffs every time. Select Oil distillate products can currently be found in dispensaries throughout Oregon and California.
G Pen Gio Pods Caliva
State THC Cartridges
Made from cannabis grown in California with no pesticides or additives, STATE THC cartridges are available in three versions or strains: Active, a sativa blended strain to energize your day and boost creativity; Balance, a hybrid strain thoughtfully produced to help relieve tension; and Relax, an indica strain for maximum relaxation. State carts are designed to help you reach your “desired state” and make it last, whether you’re on a hiking free through the mountains or binge watching a good Netflix series. Enjoy smooth hits and pure flavor.
Looking for a new cartridge that’s more than their standard blend? Go for the PLUS version of this vape cartridge, blended with an even higher cannabinoid concentration.
Jetty Cartridges
Jetty Extracts Gold cartridges are made with top quality California cannabis plants and refined through an all-natural extraction, filtration, and polishing process, leaving a product that’s pure, strong, and free of additives or solvents. Their top goal is to provide a maximum head and body high with good effects that will last through their hand-crafted batches of oil that test at full spectrum levels of 80% THC or more. Like some Stiiizy products, potency and pure flavor are key in this line!
The company’s Shelter Project is currently in line for development and will aim to provide cancer patients with healthy, clean cannabis oil at no cost to them. The Jelly Extracts quality vape cartridge can be found at dispensaries across California.
Humboldt Farms THC Cartridges
Humboldt Farms top quality full-spectrum high terpene extract vaporizer cartridges are made using a gentle, solvent-free flash-frozen hash extraction process and lab tested to ensure flavor, purity, quality, terpene profile and potency in effects with no added distillate. They also have strong products specific for strain blends of cannabis-derived and terpenes. So if you go for terpenes, this is a great choice. Terpenes bring out potency for a good overall experience.
Humboldt Farms best cartridges are available for local delivery via Eaze as well as in dispensaries across California.
Brass Knuckles THC Oil Cartridges
Brass Knuckles vape cartridge offer a full gram of flavorful, strong, potent concentrates from top-shelf indica strains, Sativa strains, and Hybrid strains. The strain variety is good and there are great flavor options and smooth hits. The cartridges contain terpenes for increased potency. The vape carts, similar to brands like Stiiizy, are available in licensed recreational and medical dispensaries in California and across the country.
We tried the Maui Wowie Sativa Cartridge and loved it the first time. The distillate is pretty strong and potent. The high potency and pure taste give a great experience.Taken in the right doses, it still lets you make the most our of your day! It’s one of the best THC cartridges!
Kingpen Cartridges
Kingpen vape cartridges are among the most popular for both medical and recreational cannabis consumers, as their THC levels test a full spectrum of 80 and 90% and the company has several High Times Cannabis Cup awards under their belt.
They’re strain specific high-potency cartridges, in fact, you can choose between 12 flavorful strains. The making involves a 5-time distilling process, ensuring a high quality distillate product that is then blended with natural plant terpenes for the best flavor and strong effects available with absolutely no additives. The lovely combination of distillate potency, terpenes, and pure flavor just hits you in all the right places.
Besides, if you have any doubt about the authenticity of the Kingpen cartridge you’ve just bought, you can check your product and learn more at KPValid.com.
Questions people ask
How do I know if a THC cartridge is safe?
Match the batch number on the package to a third-party certificate that tests cannabinoids, residual solvents, pesticides and heavy metals, and buy from a licensed retailer. During the 2019 outbreak, 78 per cent of THC-product users who named a source had used only informal ones, against 16 per cent using only commercial sources.
What caused the vaping lung injuries?
Vitamin E acetate, used as a cutting and thickening agent, was found in the lung fluid of 48 of 51 EVALI patients tested and in none of the healthy comparison group. The CDC recorded 2,807 hospitalised cases or deaths and confirmed 68 deaths by February 2020.
Does a higher THC percentage mean a better cartridge?
No. Potency describes concentration, not flavour, cleanliness or how much you take in, and it is the figure most often inflated because it is the one buyers compare. The terpene source, the certificate and the hardware tell you far more.
Why does my cartridge taste burnt?
The wick has gone dry, which happens when the oil is too thick, the tank nearly empty or the battery set too high. It is the hardware being scorched rather than a strong cartridge. Turn the voltage down and check the oil level.
Sources
- Outbreak of Lung Injury Associated with the Use of E-Cigarette, or Vaping, Products. Centers for Disease Control and Prevention. Final case counts as of 18 February 2020. .gov accessed Sep 18, 2026
- Blount BC, et al. Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI. N Engl J Med. 2020;382(8):697-705. accessed Sep 18, 2026
- Krishnasamy VP, et al. Update: Characteristics of a Nationwide Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injury - United States, August 2019-January 2020. MMWR Morb Mortal Wkly Rep. 2020;69(3):90-94. .gov accessed Sep 18, 2026
- Raber JC, Elzinga S, Kaplan C. Understanding dabs: contamination concerns of cannabis concentrates and cannabinoid transfer during the act of dabbing. J Toxicol Sci. 2015;40(6):797-803. accessed Sep 18, 2026
