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Why Is My Weed Tolerance So Low? 11 Reasons Why

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Everybody has a different endocannabinoid system (ECS), so everybody has a different level of tolerance to cannabinoids.

When it comes to talking of cannabis tolerance, people are usually referring to the psychoactive compound tetrahydrocannabinol (THC), where having a low tolerance can potentially be both an advantage and a disadvantage (i.e., it can be cheaper as less THC is needed for therapeutic effects, but it can also make an adverse side effect more likely to occur).

Here’s more on why your tolerance to cannabis might be low or lower than usual.

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You’re New to Cannabis

Those who are new to cannabis are often more sensitive to its effects. This is why going slow and low with dosage is crucial for inexperienced cannabis users, as tolerance to THC must be built up over time to reduce the chances of an adverse reaction.

Sex Differences

Women are generally more sensitive to THC than men, which fluctuates over the menstrual cycle.

This means that women may find greater analgesic properties with THC use but may also be more prone to anxiety via overuse of THC. Men’s livers also produce less 11-OH-THC, which means that women may be more sensitive to THC-infused edibles. Differences in fat distribution and hormones may also make a difference.

On the other hand, it is worth noting that some of these are studies on rodents, with some showing that there are few sex differences in THC metabolism between male and female rats. There may be several factors at play when looking at the differences in cannabis’ effects between males and females.

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Individual Differences in Endocannabinoid Tone

The term “endocannabinoid tone” refers to the way an individual’s cannabinoid receptors are distributed, cannabinoids are metabolized, and the rate at which cannabinoids are degraded. Not everyone has the same ECS, which can determine if they have a low or a high tolerance to THC.

You’re Prone to Anxiety

Low doses of cannabis and THC tend to have anti-anxiety effects, whereas higher doses may induce anxiety and panic in some. The CB1 receptor plays a key role in the development of anxiety, and it has been found that if CB1 receptors are blocked or if the gene that encodes it is deleted, anxiety increases. Low doses of THC agonize CB1 receptors, which can potentially help unblock them. Too much THC, on the other hand, may potentially prompt the release of cortisol, increasing stress.

Dietary Changes

Many factors affect the behavior of one’s ECS, and one of them is diet. Many plants contain cannabinoids or cannabimimetic (cannabinoid-like pharmacological effects) compounds, so you may find that reducing the intake of fruits and vegetables impacts your tolerance to cannabis. However, there is no definitive evidence to support this, so take it as a supposition rather than fact.

Alcohol Intake

Alcohol can enhance the effects of THC. Even if you do not mix the two, if you used alcohol the night before and it hasn’t been entirely cleared from your body, you may find that you are more sensitive to THC the next day.

Other Prescription Drugs

If you are using prescription opioids, sedatives or stimulants, you may be more susceptible to feeling the psychoactive effects of cannabis, even at low doses. THC can enhance the sedative effects of opioids or benzodiazepines, even in low doses. It is worth knowing which medications interact negatively with cannabis and CBD.

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Activity Levels

The more fat the body contains, the more THC it can absorb. One study shows that regular exercise can increase plasma THC levels in regular cannabis users, suggesting that THC that attaches to lipids (fat molecules) in the body can be “burnt off” and released into the body. Therefore, those who exercise regularly may feel THC’s effects more acutely, particularly after exercise.

You’ve Taken a Tolerance Break (T-Break)

If you haven’t used cannabis in a while, the body can “reset” its cannabinoid receptors, making them more sensitive to phytocannabinoids (plant cannabinoids) once again.


Are you taking cannabis high up on a mountain or before you get on a plane? The lower oxygen levels can enhance your sensitivity to the effects of THC.


Younger people are more sensitive to the effects of THC and so may feel its psychoactive effects far more acutely.

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The Bottom Line

Several factors can determine how sensitive a person is to cannabis, and pinpointing one particular reason a person has low tolerance can be difficult. It is more likely to be a multitude of reasons, and even an ardent cannabis user may find days they can’t take as much as they usually can.

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Frequently Asked Questions

Can vitamin C lower your tolerance to cannabis?

What does it mean when you have a low tolerance for weed?

When you have a low tolerance for cannabis (or weed or marijuana or any other such name), you cannot tolerate ingesting or administering moderate or higher levels of cannabis, particularly THC. It usually means that you are more sensitive to the psychoactive effects of THC, as well as its adverse side effects.

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