Concerned about how long cannabis stays detectable in your body? You're not alone—and the answer isn't as simple as you might hope. THC, the active compound in marijuana, can show up on drug tests anywhere from 3 days to 90 days after use, depending on several personal factors and the type of test administered.
Why Detection Times Vary So Much
After 50, your body processes substances differently than it did decades ago. Metabolism naturally slows, and body composition changes—both factors that influence how long THC lingers. According to the CDC, cannabis is the most commonly used federally illegal drug in the United States, with 52.5 million Americans using it in 2021. Yet many don't realize that THC stores in fat cells, making detection windows highly individual.
What the Tests Actually Detect
Different tests have dramatically different detection windows:
Urine tests (most common): 3 days for one-time use, 5-7 days for moderate use (4x weekly), 10-15 days for daily use, or 30+ days for heavy users, according to Mayo Clinic research.
Saliva tests: Up to 24 hours, though research shows THC can occasionally be detected up to 72 hours in frequent users.
Hair tests: Up to 90 days—the longest detection window, though less reliable for occasional use.
Blood tests: Only 2-12 hours for most people, making them less common.
The Factors That Matter Most
Your detection window depends on: how often you use cannabis, the THC concentration in your product, your metabolism and body fat percentage, your hydration level, and how you consume it (smoking vs. edibles). WebMD notes there's no reliable way to speed up THC elimination—despite what detox kits promise.
Here's the Truth About ""Detox"" Products
Those THC detox kits flooding the market? They're largely unregulated and unproven. Some can even cause dehydration or mineral imbalances. The only guaranteed way to pass a drug test is time and abstinence.
When to Talk to Your Doctor
If you're facing a drug test for employment, medical procedures, or legal reasons, be upfront with your healthcare provider. They can offer guidance specific to your situation and health profile. Everyone's body is different, and factors like medications you're taking can also affect detection times.
You're already ahead by understanding how THC detection works. If you need to clear your system, give yourself at least 30 days for complete elimination—and remember, honesty with medical professionals protects your health and safety. You've got this.