Passing an upcoming drug test can be a stressful situation. If you’ve recently used illegal substances, you may be worried about testing positive and facing consequences at work, school, or in the legal system. Some people in this predicament turn to diluting their urine by drinking extra water in hopes of lowering drug metabolite levels below detection thresholds. But is this an effective tactic and is it advisable? This article provides comprehensive information on how dilution may allow you to pass a drug test along with important reasons to avoid this risky method.
How Drug Tests Detect Dilution
1. Visually inspecting urine colour
Technicians expect urine to be pale yellow. Clear or totally colourless urine is an instant red flag.
2. Checking creatinine levels
Creatinine is a natural metabolic waste product filtered by the kidneys. Normal concentrations are 37-370 μmol/L for men and 26-340 μmol/L for women.
If creatinine is below 20 ng/mL, the sample is considered overly diluted. Diluted samples are rejected as invalid or counted as failed tests.
More advanced GC/MS confirmation tests check the ratio of metabolites to creatinine rather than a flat cutoff. This accounts for normal individual hydration differences.
Drug Cutoff Levels
Most standard urine drug tests use recommended international cutoff levels for detecting each substance. Common cutoff levels in the UK drug testing world are:
- Cannabis (THC) – 50 ng/mL
- Cocaine (COC) – 300 ng/mL
- Amphetamine / Speed – 1,000 ng/mL
- Methamphetamine – 1,000 ng/mL
- MDMA (Ecstasy) – 500 ng/mL
Your urine needs to be diluted enough to get metabolites below these thresholds.
Estimating Your Metabolite Levels
Without laboratory testing, it’s impossible to know your exact urine metabolite levels. But studies provide some averages based on usage patterns.
For example, one study found:
- Occasional cannabis users reached <50 ng/mL in 1-2 days.
- Moderate users took 3-8 days to fall below 50 ng/mL.
- Heavy users required 10+ days before dropping below 50 ng/mL.
So for a moderate smoker, drinking enough water to dilute their urine roughly in half could lower THC levels sufficiently to pass a 50 ng/mL test.
How Much Water Can You Drink?
The maximum water intake before it becomes unsafe is around 1 litre per hour. Drinking this amount rapidly will cause urine to become clear.
Clear urine and unhealthy water loading are illegal forms of adulteration in many jurisdictions.
Instead, you want to consume enough extra water to dilute metabolites while staying within normal color ranges. Studies show:
- 1 litre of water over 1-2 hours will begin turning urine clear.
- 750 – 1000 ml of water over 1-2 hours is optimum for diluting urine without becoming clear.
- Pale or straw coloured urine is expected on tests. As long as some yellow tint remains, dilution may go unnoticed.
The safest approach is to drink an extra 500-750 mL of water starting 2 hours before your test. Spread your intake over the full 2 hours and stop 1 hour before your test. Urinate frequently. This maximises dilution while less likely to arouse suspicions.
Think Twice Before Diluting Your Urine
While diluting urine may seem like an easy way to pass a drug test, there are significant risks and downsides to this approach. Here are some important reasons to think twice before attempting to pass your next drug test by drinking excessive amounts of water:
Health Risks of Water Intoxication
Drinking enough water to dilute your urine to the point of potentially passing a drug test can be dangerous and even life-threatening.
Consuming more than 1 liter per hour can result in a potentially fatal condition known as water intoxication or hyponatremia. Rapid overhydration causes critical electrolyte imbalances leading to brain swelling, seizures, coma, and death in severe cases.
While death from acute water intoxication is rare, it has happened to people attempting to dilute drug tests. More commonly, overly rapid water intake causes nausea, vomiting, headache, and dizziness.
Failed Tests and Legal Penalties
While you may think drinking water seems like a safe way to pass a test, laboratories can usually detect diluted samples.
As mentioned earlier in this article, technicians check for clear urine color and creatinine concentrations below 20 ng/mL.
Intentionally diluting your sample is considered an adulteration of the testing process. This will result in automatic failure in most cases.
Some jurisdictions also legally prohibit urine dilution and other forms of drug test tampering. Depending on the circumstances, you could face fines or other penalties for sample dilution.
Drug Use Problems Remain Unaddressed
Ultimately, even if you manage to pass by diluting your urine, it doesn’t change an underlying drug use problem. Avoiding detection may temporarily help you keep a job or stay out of legal trouble.
But you’ll remain at high risk for all the negative effects of continued substance abuse: accidents, health issues, relationship conflict, money problems, low performance, etc.
The better solution is facing your usage head-on. Passing a test by dilution just delays the inevitable need for treatment and change to turn your life around.
Better Ways To Pass A Drug Test
Rather than risking the dangers and legal issues of diluting your urine, focus your efforts on passing your test through legitimate means:
- Stop using drugs – The longer you abstain, the lower your metabolite levels will get. Stay clean for as long as possible before your test.
- Detoxification – Drug detox programs can help rid your body of substances faster through hydration, diet, exercise and sometimes medications.
- Dietary changes – A low protein, low calorie, high water intake diet may reduce metabolite levels naturally without crossing into intentional dilution.
- Medical excuses – Discuss your situation with a doctor. They may be able to medically justify postponing the test if medically safe and appropriate.
Don’t risk your health and legal record by intentionally diluting your urine. Focus on addressing any underlying issues and explore legitimate alternatives. Your long-term wellbeing is what matters most.
Photo by Zoom Testing
Zoom Testing is a leading UK drug testing company and a supplier of Drug Test Kits.
This post was originally published in 2015. It was last updated in November 2024.
