Methods on How to Test THC Content of Homegrown Marijuana

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If you’re really getting into home growing marijuana, you may reach a point where you’ll get anal about the cannabinoid content of your buds. After all, cannabinoid content is mostly what people are after when smoking weed.  

Especially if you’re growing to get high, then it’s all about the THC. We all know that most of the time, top-shelf dank can command a way higher price compared to mid-grade buds. 

Science, b*tch!

Typically, breeders raise the cannabinoid levels by pushing the boundaries of marijuana growing. They are practically plant scientists given the amount of painstaking research, experimentation, financial investment, effort and patience they put into caring for their plants and tweaking its genetics generation after generation. 

This is why some cannabis seeds and strains are unbelievably expensive, because they are actually worth years, even decades of work. 

If it sounds like you need to geek out in your approach to increasing the content of your cannabis, well that’s exactly what you need to do. Measuring how “high” you got after sampling your last batch hardly qualifies as proper testing. You have to get growing down to a science, literally. 

Factors that affect THC levels

Now what are some of the main factors that directly affect the THC content of your plants and buds? Here are 4 main ones that you as a grower should always be mindful of:

  1. Strain and genetics – as mentioned earlier, this is the single greatest factor that determines the THC content of your buds. High THC strains are only achieved through years of breeding and are typically hybrids.
  2. Light, care and nutrients – like we’ve mentioned in The Most Common Mistakes When Growing Marijuana at Home more isn’t always better when it comes to these things. The key is to find a good balance. 
  3. Harvest time – likewise, you need to know when the THC on your plants’ buds are at its fullest. Harvest too early and you lose out on the THC that could still form in the trichomes. Too late and the THC starts to degrade into CBN. 

As you go deeper into your home growing journey, you’ll likely come across a bunch of other techniques and practices that seek to push THC levels even further. Of course, you can only know for certain if everything you are doing is working if you get to measure your plants’ THC levels. 

Testing THC levels at home

There are numerous ways to test the cannabinoid levels of your homegrown buds and for homegrowers like us, your options generally narrow down. You probably wouldn’t want to invest in laboratory testing, unless you’re growing a bumper crop for selling. 

Lab testing

  • Pros: ISO-certified tests. Most accurate results. Packages typically include other required tests for compliance.
  • Cons: Expensive. Longer turnaround time.
  • Average cost range: Starts at around $120

In case you were wondering, labs usually offer testing packages rather than just testing for a single cannabinoid. This is because it is not cost efficient for a lab to run such simple tests, especially when there are already test kits and devices available on the market for consumer use. Nevertheless, potency testing is always offered at most labs but as a part of a package. An example would be Confidence Analytics’ GPM Test which tests green plant material for cannabinoids, mycotoxins, and microbial content. This testing package is priced at $120 with a sample size of 4g of flower and 2g of all other types. 

A word of warning though. If you wish to have your samples tested at a lab or anything that would require you to ship marijuana, it will likely be seized by the authorities. Cannabis is still illegal at the federal level which is why it is not advisable to ship samples across state borders.

Other cannabis lab testing options: EVIO Labs, ACS Labs, Encore Labs.

Dispensaries and testing centers

  • Pros: Accurate results. Provides lower cost options that caters to the testing needs of home growers.
  • Cons: You have to go to their location or have your samples shipped.
  • Average cost range: Starts at around $50 to $100

Because of the prohibitive cost of lab testing for consumers, there are dispensaries and organizations that have put up testing centers that charge a cheaper fee. Cannabis companies like Ceres Natural Remedies in Vermont have put up cannabinoid testing centers that cater particularly to the needs of home growers. For non-medical marijuana patients, the cost of testing 4 major cannabinoids including THC and CBD is $75.

Other cannabis testing dispensaries/centers to look at: White River Grow Pro, Flower Potency Testing

Testing gadgets

MyDx® Analyzer 2.0 + CannaDx™ Sensor Kit: Grower’s Package
  • Pros: Very convenient, instantaneous results. Repeated onsite testing. Fairly accurate.
  • Cons: Expensive and may not make sense cost-wise to casual home growers.
  • Average cost range: $1000 upward.

If you can afford to spend and want to go the high tech route, you could use a gadget like the CannaDx. On its website, MyDx says their device should eliminate the need for costly lab testing and also give consumers a faster and more convenient way to test. 

The handheld CannaDx is also able to measure terpene content aside from THC, CBD and CBN and has a companion smartphone app where you can use all of its features. If you don’t mind spending $999 plus an additional $14.99 for the disposable inserts, then this is the device for you.   

Other cannabis testing gadget options: GemmaCert Cannabis Analyser, PURPL Pro,

Testing kits

Cannalytics Supply 16/20 THC/CBD/HEMP TEST KIT
  • Pros: Very convenient with fairly accurate results. Onsite testing and instant results.
  • Cons: Can only be used once or a few times. Can be complicated for beginners.
  • Average cost range: Around $100 to $200

Testing kits are so far, the most convenient and popular choice for home growing hobbyists. Kits used to be the cheapest way to test too, until testing services like Ceres Natural Remedies came along. 

Thin Layer Chromatography, CTK Test Kits CTK Test Kit # 1 (20-25 test)

You can order kits like Cannalytics Supply’s Cannabis THC/CBD/HEMP test kit or TLC Lab Supply’s Thin Layer Chromatography, CTK Test Kits online, starting at $99 and $159.95 respectively. Both kits can be used on flowers and concentrates and the general feedback on them is that they can give fairly accurate results, if done correctly. However, those who have no prior experience with these testing methods should probably go through the instructions and tutorials on the manufacturer’s website before anything else. 

Other cannabis testing kit options: ProTest, Alpha CAT

Frequently Asked Questions

What is a THC test kit?

Kits used for testing the potency of marijuana are also called “THC test kits”. Most testing kits are able to show the levels of cannabinoids other than THC. These cannabis testing kits are different from drug test kits that detect THC.

What is the best way to test the THC of homegrown weed?

This depends on what kind of grower you are. Lab testing, which is expensive, only makes sense for commercial growers whose product needs to comply to standards. Home growers should go for the more economical option, which are testing devices or testing kits.

How do I test the THC content of my marijuana?

You can have the flowers, dried buds, or extracts/concentrate tested at a lab, or by using a testing device or kit.

Can I test marijuana THC content at home?

Yes. You will need a cannabis testing kit or device to test the cannabinoid content of your homegrown weed. However, if you need accurate test results for microbial or heavy metal content, lab testing may be more advisable.

How much does it cost to test THC content of cannabis?

This will depend on the testing method used and what kind of home growing setup you have. Even though lab testing is expensive, it is typically still economical for commercial growers who need to test several batches not only for cannabinoid content but also for others required by compliance standards. Lab test packages often start at around $150 upward while consumer marijuana test kits are available at just $100.

What affects THC levels in my marijuana?

THC and cannabinoid levels in general are largely determined by the strain of marijuana you are growing. There are certain cannabis strains known for having a high THC range, but a plant can only maximize its THC levels if it is well-cared for.


Now that the medical and recreational marijuana industry is picking up due to growing social acceptance, we can expect more methods of testing to be available to home growers. As of now, the only testing options that make sense for those who grow for personal use are gadgets like the CannaDx and various potency testing kits. Home growers really do not need pinpoint accurate results from a lab since they do not have to adhere to any compliance standards. 

When using these consumer testing products, you may notice that results may vary from batch to batch. This is ok and probably does not mean that you got a faulty kit. Remember that you are dealing with a plant and as mentioned, there are a lot of factors that can impact its THC levels. You should use these kits not really to get accurate THC readings but rather to see whether your growing techniques are actually working.    

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