This is How Long Does Weed Stay In the System of an Athlete

Daniel Miller
Daniel Miller, Ph.D Pharmacology, Drug Testing Specialist

Last updated on 2024 Jun 11

Depending on many factors (to be discussed later), it can take about 3 days to completely rid an athlete’s system of weed, If you’re a first-time smoker.

For frequent users, the detection window is about 5 to 7 days. Those who smoke not less than a joint daily will test positive for at least 30 days.

But, here’s the thing: we know that THC, the active substance in weed that drug tests are looking for, is stored in body fat.

Athletes have lower body fat and high metabolic rates. This means that body fat is burned quicker and THC is released and excreted quicker. Thus THC tends to stay in their system for a shorter period.

So their chances of passing a drug test are better compared to non-athletes.

I’ll explain to you how long weed stays in the system of an athlete, what factors affect this time, and how you can calculate how long an athlete’s system will take to remove weed from their body completely.

Let’s Calculate For How Long Does Weed Stay In The System Of An Athlete

Let me introduce you to the THC calculator – a statistical tool that can help you quite accurately determine how long THC will be completely removed from your system.

But bear in mind that the results of this calculator are approximate. Too many factors affect marijuana metabolism. I’ll explain it later.

For athletes, remember that they:

  • are slimmer (have less body fat)
  • have a higher metabolic rate
  • consume more water

All these factors mean that the time for weed to clear their system will be lesser than normal users.

Anyway, after you’ve selected the metric units you want your answer in (inches, centimeters, pounds, kilograms), the basic information you need to get the most accurate clearance time is:

  • gender
  • weight (lbs./kg)
  • age
  • height (inches/centimeters)
  • frequency of weed usage (be as honest as possible!)

After crunching some numbers, the calculator will give you an estimation of the time it will take for weed to clear your system!

If you’re a math geek and want to crunch numbers yourself, say hello to the concept of ‘half-life’ – the time it takes for half of the THC in the body to be excreted.

According to a study, the excretion half-life during the first five days following weed intake was approximately 1.3 days (27 hours) for infrequent users.

For frequent users, the half-life was 1.4 days (26 hours), while some even reported 10.3 days.

And, for heavy users, half-lives would be longer.

For our calculations, let’s assume that a first-time, slim athlete with a fast metabolism smoked 1g of marijuana with 20% THC content. This resulted in 200mg of THC in his body.

According to another study that will help our calculations, if there is 27 mg of THC in a joint, the amount of THC-COOH in a smoker’s urine would peak at 180 ng/mL after 4 hours.

Using simple cross-multiplication laws, after smoking 200mg of weed, the concentration of THC-COOH in the urine of an athlete would be 1330ng/ml.

  • After 26 hours, the concentration would be 665ng/ml.
  • After 52 hours, it would be 332ng/ml.
  • And fast forward to 130 hours – the concentration would become 40ng/ml, which is below the detectable level of a urine immunoassay drug test. This would take about 5 days and 10 hours.

For a gas chromatography urine drug test, which is more sensitive, the cutoff value is 20ng/ml. So that means 2 more days for THC to become undetectable from the urine of an athlete.

How Long Does Weed Stay in Urine, Blood, Saliva, and Hair


Weed can be detected in urine after last use as follows:

  • Occasional users (weed intake at least three times per week): 3 days
  • Moderate users (weed intake at least four times per week): 5 to 7 days
  • Chronic users (daily weed intake): 10 to 15 days
  • Chronic heavy users (weed intake several times a day): more than 30 days


Weed remains detectable in blood for about 1 to 2 days. But in certain cases, it has also been detected after 25 days.

As is obvious, chronic heavy use will increase the period of detection.


If the drug test involves saliva, weed will be detectable after last use as follows:

  • Occasional users: 1 to 3 days
  • Chronic users: 1 to 29 days


A fun fact while we’re discussing hair: your hair grows roughly 0.5 inches every month!

According to simple math, a 1.5-inch hair segment sample taken close to the scalp will provide an estimate of weed use for the last 3 months.

Why Is THC Detectable So Long After Use

As I’ve mentioned before, weed’s active ingredient is the chemical THC, or delta-9-tetrahydrocannabinol (delta-9-THC-COOH).

When you smoke weed, THC travels through your lungs and enters your bloodstream.

THC is extremely fat-soluble. About 70% of the THC from the blood gets “trapped” by body fat tissues.

The remainder is metabolized by the liver and excreted via urine and stool.

From the fat THC is slowly released into the blood. That’s why THC is detectable in your system for weeks and months.

What Factors May Impact THC Metabolism

What I’ve mentioned earlier in terms of the time it takes to rid your body of weed are just generalizations.

Many things influence the metabolism and removal of weed from the body.


Women metabolize THC at comparatively lower rates than men, mainly because of their higher body fat levels.

Because THC is stored in body fat, women will store more THC, which will gradually be released into their bloodstream over a longer period.

Frequency of Use

For first-time consumers, THC generally remains in the system for about 3 days.

For those taking weed about 3 to 4 times a week, the detection window is closer to 7 days after last use.

THC can be detected for daily users for as long as 30 days, and in some cases, even more.

The potency of Strain and Your Tolerance

Different strains of marijuana have different concentrations of THC.

The stronger the weed, the longer it will take to be metabolized and removed from your body.

Method of Consumption

Smoking will get you high within minutes.

Edibles will take longer to be metabolized and kick in.

Lung Capacity (for smoking and vaping)

How much weed is inhaled and how long you hold your breath after each puff will determine how much THC enters and stays in your system.

Body Fat or Body Mass Index (BMI)

THC is fat-soluble, which binds to and is stored in body fat.

A higher percentage of body fat means a longer time to metabolize cannabis.


The faster your metabolism, along with lower body fat, the faster THC will be metabolized and removed from your body.

However, metabolism is influenced by age, exercise, and different health conditions.


Food deprivation, exercise, and weight loss can increase the release of stored cannabinoids from adipose (fat) tissues.


Flushing large amounts of water into your system will largely dilute the level of THC in urine and make its removal quicker.


It would take about 8 days to significantly lower the concentration of THC-COOH in the urine of an athlete to below the detectable level of urine drug tests.