HalfLifeDB Drug half-life explorer

Half-life profile

THC half-life calculator

Estimate how much THC remains in your body over time using a first-order elimination model. Values are approximate and should not replace lab testing or medical advice.

Now estimated in body: 51.41 mg(51.4% of starting amount)Half-life used: 25 h

Pharmacokinetics at a glance

Mean half-life 25 hours

Typical detection windows

Detection windows are approximate and depend on dose, frequency, metabolism, specimen cutoffs and lab methods.

Matrix Window
blood Detectable for several hours after occasional use; heavy or chronic use can lead to low-level detection for days.
urine Occasional use may be detectable for 2–3 days; regular or heavy use can remain positive for multiple weeks.
saliva Often detectable for up to 24 hours in occasional users and longer in chronic users.
hair Can be detectable for months depending on hair length and pattern of use.

How this model treats THC

The calculator uses a simple one-compartment model with first-order elimination. Every half-life, the remaining amount is halved. Real-world pharmacokinetics can be more complex (multi-compartment models, active metabolites, saturable metabolism).

Medically reviewed sources

  1. Sharma P et al. Chemistry, metabolism, and toxicology of cannabis (2012).
  2. Mørland J et al. Δ9-THC is present in the body for a long time (2020).

Notes

This page is for educational and informational purposes only. It does not provide medical or legal advice and does not tell you whether you are safe to drive, work or pass a drug test.