According to a Drug and Alcohol Dependence study conducted in 2016, a typical marijuana joint weighs around 0.3 g has a total of 20 mg of THC (or tetrahydrocannabinol) in it.
However, the amount of THC in the joint can vary due to:
- Personal preference and usage.
- How often the individual smokes.
- What part of the cannabis plant you smoke (e.g., leaves vs bud).
- How potent a particular strain is.
As you can see, even if two people are using the same type of marijuana, they may not end up with the same amount of THC intake from smoking one joint.
There is a standard calculation that can be used to estimate the amount of THC in a joint.
How to Calculate How Much THC Is in a Joint
According to the analytical testing lab, Werc Shop, the theoretical maximum amount of THC possible in a joint is estimated to be:
THC max = THC + THCA / 358.48 * 314.47
Though not a perfect measure, this formula can:
- Give you an idea of how much THC is in a joint.
- Allow you to estimate how much THC you are ingesting.
- Provide a rough idea of the strength of different strains.
Because there is a difference between how much THC in a joint versus how much is consumed, it can get a little complicated.
Why Is it Difficult to Calculate How Many Milligrams of THC Is Consumed From a Joint?
Although a joint might contain 20 mg of THC, it doesn’t mean you’ll consume that much.
But why is there a difference between how much THC is in a joint and how much you consume?
- A typical joint contains mostly THC acid in the non-psychotropic form, THCA.
- When it’s ignited, the heat from burning converts the THCA to psychoactive THC through a process called decarboxylation, which is the process of removing a carboxyl group from an acid.
- The amount of time and temperature it takes for decarboxylation will change how much THC someone consumes in one joint.
So, when you burn the joint, about 40-50% of the THC is lost according to the UK Cannabis Internet Activists in 1990.
That’s only one factor that influences how much THC you consume from a joint.
There are other factors to be aware of when calculating how many mg of THC in a typical joint.
How Much THC Is in a Joint? 5 Factors That Influence Your Consumption of THC
Your understanding of how …
- THC is ingested from a joint, and
- The factors that influence it
… can impact your decision on how many times to smoke.
Let’s take a look at five factors that influence how much THC you consume.
#1: Joint Size
The amount of marijuana you smoke will have a big influence on how much THC enters your system.
Therefore, the size of your joint is an influencing factor on how much THC you consume because:
- The smaller the joint, the less THC will enter your system.
- A longer and wider joint means that more of it is burned away by time or air resistance before reaching you.
- More cannabis per joint increases the chance for ingestion into the body.
The size and length of the joint will determine how quickly THC enters your bloodstream.
When it comes to how much THC you inhale, the higher the level of potency of the marijuana, the higher intake of the chemical.
It is important to note that a person will not ingest 100% of the THC in the joint because:
- When you inhale cannabis smoke, some THC will be lost in the process of combustion.
- Not everyone completes their inhalation before passing the joint to someone else or putting it down.
- Not all molecules of THC are vaporized by heat and can remain behind as part of a joint’s ash.
The last point leads to the next determining factor for THC consumption, known as bioavailability.
Bioavailability is the proportion of a drug that enters systemic circulation following administration.
Unlike other methods of consumption such as eating or drinking cannabis products, smoking a marijuana joint increases bioavailability due to:
- How quickly it reaches your brain and gets absorbed into your bloodstream.
- Its ability to cross the blood-brain barrier more easily than other methods of consumption.
- How some of the THC is lost in sidestream smoke.
Studies show that THC bioavailability averages at 30%.
The THC content in a joint can vary, depending on how long it takes you to smoke the joint and how much time you spend between inhales.
How Does Bioavailability Affect Your High?
The higher the percentage of bioavailability, the more THC will be present in your bloodstream and consequently how high you can get.
For example, the THC content can vary from 0.03 mg to as much as 20mg per joint.
The percentage of bioavailability also determines how high you will get:
- 30% is typically considered low-to-medium potency
- 40% is often medium
- 50% or higher would be considered potent or strong
#4: Physiological Factors
There is no standard puff measurement when it comes to joints.
Any given joint could contain significantly more or less THC than the last.
However, the amount of THC you consume can differ based on physiological factors like:
- How much is inhaled
- Lung capacity
- How long you hold your breath; and
- The amount of THC is left in the exhale.
Other considerations include:
- If someone has never smoked a joint before, the THC content of one joint will cause different effects than someone who smokes frequently.
- As you continue to smoke more and more marijuana joints, your tolerance for THC may increase which could result in your body getting used to how much is in each joint.
- Some joints can contain considerably more or less potency than others depending on external factors.
If this happens, then the person smoking might not get as high or they might require
#5: Joint Shape
The shape of a joint can also impact the consumption levels of THC.
This is because the amount of cannabis that is burned at any one time will be different depending on the shape of the joint.
So, what are some examples of how joint shape affects consumption levels?
- Joints with a long, thin shape require you to draw in less smoke and therefore absorb less THC than joints with a shorter and fatter shape.
- As the joint burns, THC intensifies near its end. And as a result, people experience higher levels of THC in it.
- Holes in a joint create more surface area for the THC to burn, which means that people get higher levels of THC.
- A joint with a fat end may result in less THC consumption.
In the end, it all depends upon how much THC is in your joint and what you are smoking.
Still Curious How Many Mg of THC in a Joint You’ll Consume With One Joint? Try Out This Experiment
If you’re interested in figuring out how much THC you can consume from a joint, try out the following experiment:
- Find out the mg of THC and potency of a joint you will smoke.
- Keep track of how many puffs you take so that you can know your THC intake.
- Calculate your average puff by:
- Use the max THC calculation to get an idea of how many milligrams of THC there are.
- Don’t forget to consider the percentage of sidestream loss; and
- Divide by the number of puffs you took from the joint to find how much THC is in each one.
Keep in mind that there will always be an error factor with this experiment.
Can You Definitively Determine How Many Mg of THC in a Joint Is Consumed?
To accurately measure how much THC is consumed, you must do blood labs.
It’s the only real way of knowing.
But how can you use a blood test to definitively determine how many mg of THC you consumed in a joint?
It’s as simple as a few steps:
- Get blood work completed before smoking a joint and take note of the amount of THC in your bloodstream.
- Smoke a joint after the initial blood test.
- Get another blood test done and take note of the mg of THC that was present after smoking a joint.
- Subtract the amount of THC that was in your bloodstream before smoking a joint from the amount of THC that was present in your bloodstream after smoking.
The result is how many mg of THC you consumed in a joint.