How long does a substance stay detectable in the body? This calculator estimates the elimination of various psychotropic substances — with course curves, a tolerance estimate, and details for each one. After entering the substance and time of intake, the curve shows the estimated course including a range of uncertainty, since elimination varies considerably from person to person.
Note: for educational purposes only, no guarantee of accuracy — everybody's metabolism responds differently.
* This is only an estimate — the actual time can differ considerably from person to person. See “What this calculator is not for”.
Each curve shows the estimated level of one substance in the body since the last intake. The shaded area marks the range of uncertainty between fast and slow elimination, because the actual value varies from person to person. Drag the time axis or the slider above to compare a point in time other than now.
* This is only an estimate — the actual time can differ considerably from person to person. See “What this calculator is not for”.
Elimination and tolerance are two different things: the substance is gone within hours, but the receptors take days to weeks to readjust. The slider shows roughly how far sensitivity should have returned after a break — as an order of magnitude, not a measurement.
* This is only an estimate — the actual time can differ considerably from person to person. See “What this calculator is not for”.
This overview sums up the key values for each substance: the current level in the body, the peak so far, when about half is expected to be eliminated and when practically nothing is detectable any more. Subjective experience of the substances may differ from their levels in the body.
Not a fitness-to-drive test. Residual alcohol estimates can be off by several tenths of a per mille in individual cases, THC curves even more. In court and on the road, what counts is the measured value, not the calculation. In Germany the limits are 0.5 ‰ for alcohol and 3.5 ng/ml THC in blood serum, and zero for novice drivers and under-21s — and if you have used, don't drive.
Not medical advice. Half-lives are averages for healthy adults. Liver and kidney function, medication, pregnancy, smoking and genetic differences in CYP1A2 shift them considerably — for caffeine by a factor of three or more.