How Long Does THC Vape Stay in Your System?

When people ask how long does THC vape stay in your system? They essentially want to know for how long THC remain in the body. Well, most studies suggest that THC and other cannabinoids have quite a long half-life, and thus, they stay in the body for more than a day but in traces. Most of it leaves your body in 6-8 hours and becomes undetectable (1,2).

As a doctor and a person who has extensive experience in medical research, I will try to explain this topic in simpler terms. There are a few things to understand here.

Although THC may remain in the body for more than a day, it will only remain in traces. So, it won’t be detectable using commonly used blood or urine tests. After a day, it would only be detectable using very sensitive tests often used in clinical research.

However, there is more to it. People do not vape THC once. If they buy a THC vape pen, they are quite likely to use it continually for a few days or even months. In such cases, things change a bit.

For this, one needs to understand the concept of half-life. Studies show that the half-life of THC is more than a day. In some cases, it may be a few days.

Half-life means after how much time the concentration of a specific compound (ingested or inhaled) would fall below 50% levels in the blood from its peak value. So, if one vapes THC within a few minutes, the THC peak level is reached. After that, it gradually declines, falling below 50% in a few hours to more than a day.

THC is mainly metabolized in the liver, and the kidneys remove its metabolites. So, there is a substantial individual difference. Since the liver function and metabolic rates differ among individuals, THC is metabolized at different rates among different people. Moreover, health conditions and age also affect how long a THC vape lasts in the system. Further, remember that THC dosage also decides how quickly it is metabolized. Legal vapes contain tiny amounts of THC, so it is metabolized pretty quickly, generally within 6-8 hours. Things are different if one smokes a weed or marijuana.

So, one sees that after a day, a very small amount of THC will still be in the system. Now, when you vape the next day, it will result in an even greater THC blood concentration than the first day. So, on regular THC vaping, its blood concentration keeps climbing for three to five days. This explains how THC, even in small dosages, can provide health benefits on consistent use.

However, after three to five days, a peak is reached, and vaping daily does not increase THC blood levels any further. This peak level can be maintained with regular vaping.

But, once the person stops vaping, THC’s blood levels start declining pretty quickly. In most people, it will become undetectable after 24 hours. After all, legal THC vapes have only a tiny THC amount, and the body can eliminate it pretty efficiently.

Of course, although THC will not be detectable in urine and commonly used blood tests after 24 hours, it remains in the body in traces for much longer. The so-called bioavailability and pharmacokinetics studies suggest that THC may last in the system or body for several days in traces (when used at massive dosages). This means that after about a couple of weeks, the body will be completely clean of any THC; even traces of the compound won’t be there.

So, it is good to know that THC vape does not stay for long in the system. Most of it is removed by the liver from the body in 6-8 hours. However, traces may remain in the body for longer. But, these are few molecules, and they are undetectable by commonly used tests.

References

1. Millar SA, Stone NL, Yates AS, O’Sullivan SE. A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans. Front Pharmacol. 2018 Nov 26;9:1365.
2. Mørland J, Bretteville-Jensen AL, Bramness JG. On the duration of cannabis effects and the presence of THC in the body. Addiction. 2023;118(2):390–1.