This is a question that we get asked frequently. How long will my weed high last? Although this varies for different people, we will help answer this age old question. The University of Sydney published an article in the Neuroscience & Behavioral Review in 2021 about the “window of impairment”. They found that depending on the users dose of THC, how they ingested it, and their overall tolerance to THC, effects lasted anywhere from 3-10 hours.

Data pointed to the average for most users was around 4 hours. When users hit a joint or bowl their effects lasted closer to 3 hours, while users engaging in a dab session found effects lasting upwards of 6-10 hours. When it came to edibles they found that heavy edibles lasted more towards that same 6-10 hours for some users, while the average consumer found that a 20 mg dose of edibles lasted an average of 4-5 hours. We (Planted) agree with this data overall when looking at a very general consumer base. However we found that users with higher (no pun intended) tolerances saw effects lasting from inhaling closer to 1-2 hours, and ingesting via edibles or beverages closer to 2-3 hours. Tolerance seemed to not effect onset time much, but rather the period of time it takes for those effects to subside as well as the overall level of intoxication received.

80 more data points

The research group then analyzed data from 80 other scientific studies about cannabis dosage and levels of intoxication. Their focus was on how intoxication from THC effected driving skills and awareness, so much of the questioning was skewed in that direction. None the less it provided the same good data they were looking for.

They found that consumers of cannabis recovered most of their driving related functions within 4-5 hours when the consumption method was inhaling and the dosage was around 20 mg of THC. When taking the same amount but in edible form, users took longer to recover driving related skills. The average cannabis gummy on the market consists of 10 mg of THC where as the package itself contains 100 total mg of THC divided into 10 pieces/servings. This study and data considered 10 mg of THC a moderate dose for most people.

The overall findings were that there was no universal answer to this question and that too many factors were at play for each consumer. But again we can play the game of averages and get ourselves a range to educate consumers on. The good news is each of these studies for the most part found the same data, and very similar ranges of onset and effect times.

Edibles have longer onset time and last longer

There is an obvious difference between inhaled and ingested THC (edibles). For example when you smoke or vape cannabis products, onset times are usually minutes. Beverages or edibles usually have an onsite time of 30-120 minutes. When they took the same 20 mg of cannabis via inhaling VS ingesting orally, the effects lasted close to the average of what we said above, with 4 hour average on inhaling and double that (8 hours) when digested via edibles or beverages.

Regular THC Consumers show signs of less impairment

As consumers use THC and cannabis more regularly both their body and mind will build up a tolerance for these ingested cannabinoids. The University of Sydney confirmed this in their research.

Co-author of this study Dr. Thomas Arkell, also from the Lambert Initiative, stated: “We found that impairment is much more predictable in occasional cannabis users than regular cannabis users. Heavy users show significant tolerance to the effects of cannabis on driving and cognitive function, while typically displaying some impairment.”