In family law, drug and alcohol testing often becomes a crucial element in determining custody, visitation rights, or compliance with court orders. When the well-being of a child is on the line, the integrity of drug and alcohol test results cannot be compromised.
At Cellmark we take that responsibility seriously, but that doesn’t mean we can’t spot a bit of creativity when someone tries to outsmart the system (spoiler: they rarely succeed).
Our drug and alcohol testing services, including blood and urine alcohol marker testing and hair drug and alcohol testing, are conducted under strict chain of custody protocols to ensure the results are legally defensible.
But what happens when someone tries to cheat a drug test? Here’s a closer look at the most common attempts and how we counter them.
How to Cheat a Drug Test - Common Drug Test Cheating Tactics
1. Substituting or Using Synthetic Urine
Donors may try to smuggle synthetic urine or someone else’s ‘clean’ sample into the collection site. Heat pads or small containers may be used to maintain body temperature. The picture above includes some of the different methods that may be used by donors, top marks for inventiveness!
Our Response: Urine collections are conducted in a controlled environment. The taps and toilet cistern are taped up before the sample is given to avoid anyone using the water from them. The temperature of the urine is also recorded, as a genuine sample would be at body temperature.
2. Dilution or ‘Flushing’
Some donors try to dilute their urine by drinking excessive fluids or using commercial ‘detox’ drinks that claim to flush out ‘toxins’.
Our Response: Urine samples are tested for creatinine to detect dilute or abnormal samples. Creatinine levels below normal occur when urine has been diluted, either directly or by drinking excessive fluids before providing the sample. Even the most hydrated humans don’t produce water disguised as urine.
3. Hair Bleaching or Shaving
To avoid detection in hair drug testing, some individuals may bleach their hair or attend the appointment freshly shaven.
Our Response: Hair drug testing can be conducted using head or body hair however a segmented analysis cannot be provided if body hair is used. Bleached hair can still be tested, we would always ask the donor about the products and treatments they use on their hair at the time of the sample collection.
4. Use of Hair Detox Shampoos
There are many hair detox shampoos available, all claiming to remove drug or alcohol evidence from hair to ‘pass’ a hair drug test.
Our Response: While Detox shampoos may remove some evidence of drug and alcohol use, they are unlikely to remove all trace of drug or alcohol use.
5. Tampering with Blood Testing
While less common, some may try to delay or avoid blood testing to allow alcohol markers to clear their system.
Our Response: Testing multiple sample types (e.g. blood, urine, and/or hair) for alcohol markers provides a better overall view of a donor’s alcohol use.
Why Chain of Custody Matters
Every sample collected follows legally recognised chain of custody protocols. This means:
- Samples are labelled, sealed, and tracked from the moment of collection,
- Every person who handles the sample is documented,
- The test results are court-admissible and defensible in legal proceedings.
Comprehensive Testing Options
We provide flexible, reliable testing solutions tailored to family law cases:
- Blood Testing – accurate detection of recent alcohol use,
- Urine Testing – detects recent alcohol use, easy sampling and useful for random or scheduled monitoring,
- Hair Testing – reveals patterns of drug use over a period of months. Ideal for long-term monitoring as it can provide details of a person’s alcohol use over longer periods of time.
While individuals may try to manipulate test results to try and ‘pass’ a drug or alcohol test, professional oversight, proper collection procedures, and lab verification drastically reduce the chances of successful tampering. At Cellmark, we take every measure to ensure results are reliable, trusted and provide legal peace of mind.
If you're a solicitor, social worker, or family court professional looking for dependable drug and alcohol testing, we’re here to support your case with the highest standards in the industry.