Article updated: 2023 Jan 30. doi: 10.101323/ Author Leslie Griver, Robert Henry

Will diuretics like Lasix and furosemide help pass a drug test?

Yes, diuretics like Lasix or furosemide can help you pass a drug test. The anti-doping agency even bans them because athletes use diuretics to mask drug usage.

How diuretics help to pass a drug test

We’ll talk about marijuana here, but the principle is the same for other drugs too.

When we smoke weed, THC, the active component in marijuana, gets into the blood. With the blood, it gets into the liver.

It is converted(metabolized) into several metabolites in the liver and then excreted into the urine and feces.

We oversimplified the process for easier understanding.

When you use diuretics, they increase the urine output, but the amount of THC metabolites that enter the bladder is the same.

Thus, the concentration of THC metabolites in the urine becomes lower.

Every urine drug test has a cutoff level – the concentration of metabolites required to cause positive results.

If you dilute your urine enough for the concentration of THC to drop below the cutoff level(50ng/ml usually) – you will pass the test.

This effect is temporary because when your urine output returns to normal values, the concentration of THC will increase.

Why this method is not reliable

You don’t need to take diuretics to increase urine output. You can do that by drinking 17-25 oz of water each hour for several hours before the test.

Diluting your urine with Lasix, furosemide, or other diuretics, as well as with water, will also flush out the essential minerals.

This will cause the creatinine levels and the specific gravity of the urine to change. As well as, the color of your urine will be pale.

The lab technician will check all these parameters and reject your sample as diluted.

To avoid this, you need to drink electrolytes to restore specific gravity, take creatine to restore creatinine levels, and use vitamin B to restore the urine color.

We explained the process step by step in this guide: How To Detox THC in 24 Hours. Step By Step Guide