How long does weed stay in your system?
Short answer:THC metabolites are typically detectable in urine for about 3 days after a single use, 7–21 days for regular use, and 30 or more days for daily heavy use — while blood detects roughly 1–2 days and hair up to 90 days.
The longer answer
The high lasts hours; detection lasts far longer. THC is fat-soluble, so it is stored in adipose tissue and released slowly, which is why frequency of use is the single biggest variable in any detection window.
Body composition, metabolism, hydration, dose, and potency all shift the timeline. There is no reliable way to speed clearance — detox drinks and heavy hydration mainly dilute a sample rather than remove metabolites.
Test type matters as much as usage: saliva tests catch recent use (hours to a couple of days), blood is a short window used for impairment, urine is the standard employment test, and hair testing reaches back roughly 90 days.
Key takeaways
- Single use: roughly 3 days in urine. Daily use: 30+ days.
- Blood: 1–2 days. Saliva: up to about 72 hours. Hair: up to 90 days.
- Frequency of use outweighs every other variable.
- No product reliably accelerates THC clearance.
Related questions
Does exercise clear THC faster?
Exercise may briefly raise blood THC levels by mobilising fat stores, so heavy exercise right before a test can work against you.
Do edibles stay in your system longer?
Detection windows are broadly similar, but edibles often involve a larger total dose, which can extend how long metabolites remain measurable.
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Educational information only, not medical advice. Figures are directional and batch-dependent — see our accuracy methodology.