Xylazine half-life
A 2026 naturalistic emergency-department study estimated a mean xylazine half-life of 345 minutes in eight participants after nonfatal opioid overdose.
Every curve begins at 100%. No dose or measured body concentration is assumed.
X-axis: elapsed time. Y-axis: modeled percentage of the relative starting point remaining. This is a mathematical visualization, not a personal concentration estimate.
Xylazine: evidence and interpretation notes
What the representative value means
A 2026 naturalistic emergency-department study estimated a mean xylazine half-life of 345 minutes in eight participants after nonfatal opioid overdose. This is the first cited human estimate here, but the small co-exposed cohort makes it a contextual result rather than a general-population norm.
5.75 hours is the single value used to make the Xylazine in a small opioid-overdose cohort decline curve inspectable. The output is relative percentage remaining; it does not establish impairment, detection, or safe-activity timing.
Xylazine exposure is usually interpreted in public-health and toxicology context, not consumer dosing context. The chart does not predict wounds, sedation, overdose severity, or emergency needs.
What each source contributes
- PubChem: Xylazine. This identity record confirms names and compound identity and does not supply a human half-life.
- NIDA: Xylazine. This supporting literature record adds compound-specific background and is used only within the limits of its design.
- Love JS et al. Pharmacokinetics of xylazine and fentanyl after non-fatal opioid overdose (2026). This human pharmacokinetic record adds measured route, analyte, and population context and does not become a universal result.
- Love JS et al. Pharmacokinetics of xylazine and fentanyl after non-fatal opioid overdose (2026). This human pharmacokinetic record adds measured route, analyte, and population context and does not become a universal result.
For Xylazine, the numerical model is tied most closely to NIDA: Xylazine. As a supporting literature record, it adds compound-specific background; it is used only within the limits of its design.
Why there is no range on the chart
This profile plots 5.75 hours for Xylazine in a small opioid-overdose cohort without adding an unsourced high-low band. A single supported center is more honest than manufacturing a range from unrelated routes, populations, or formulations.
InterpretationReading the curve and its category context
Reading this curve
HalfLifeDB uses 5.8 h as a representative input for Xylazine in a small opioid-overdose cohort. In the simplified model, about 5.5% remains after 24 hours and about 3% remains after five half-lives, or roughly 28.8 h.
This sits in the same-day range. The chart is useful for seeing the bend of the curve across a day or two, but it should not be treated as a personal clock. The curve is relative: it does not estimate a person's measured concentration, effects, impairment, or time to clearance.
public-health adulterant context
Public-health adulterant entries are included for educational context and may have source profiles that differ from ordinary therapeutic labels or controlled pharmacokinetic trials.
- The curve is not a safety, exposure, or emergency-response guide.
- Real-world mixtures and routes are outside the model.
- Public-health alerts, toxicology, and clinical context should be read separately.
ComparisonTimeline checkpoints and nearby profiles
Xylazine timeline checkpoints
| Elapsed time | Modeled remaining | Reading note |
|---|---|---|
| 6 h | 48.5% | Meaningful modeled decline, not near-zero |
| 12 h | 23.5% | Long-tail portion of the model |
| 24 h | 5.54% | Low modeled remainder, not a clearance guarantee |
| 2.0 days | 0.31% | Low modeled remainder, not a clearance guarantee |
| 3.0 days | 0.02% | Low modeled remainder, not a clearance guarantee |
Nearby profiles by half-life
These entries sit near Xylazine within the public-health adulterant group when sorted by representative half-life. That makes them curve comparisons, not statements about equal potency, effects, or risk.
No nearby published profiles are available in this category.
EvidencePharmacokinetic inputs and source trail
Pharmacokinetics at a glance
| Representative half-life | 5.8 h |
|---|---|
| Modeled analyte or phase | Xylazine in a small opioid-overdose cohort |
| Curve type | Normalized, first-order decline |
Selection note: A 2026 naturalistic emergency-department study estimated a mean xylazine half-life of 345 minutes in eight participants after nonfatal opioid overdose. This is the first cited human estimate here, but the small co-exposed cohort makes it a contextual result rather than a general-population norm.
Sources and evidence context
A linked record is not automatically proof of the displayed value. Study, labeling, review, and compound identity sources serve different purposes; notes below identify limitations when they are known.
- Identity record PubChem Compound Summary: Xylazine.Compound identity and naming record. It supplies chemistry context, not independent numerical support for the model.
- Peer-reviewed source NIDA: Xylazine.Supporting literature record. Its role and study design should be read from the linked source before applying any numerical finding.
- Research abstract Love JS et al. Pharmacokinetics of xylazine and fentanyl after non-fatal opioid overdose (2026).Naturalistic emergency-department study. Eight participants contributed to the mean 345-minute xylazine half-life estimate; fentanyl and other exposures limit generalization.
- Research abstract Love JS et al. Pharmacokinetics of xylazine and fentanyl after non-fatal opioid overdose (2026).Naturalistic emergency-department study. Eight participants contributed to the mean 345-minute xylazine half-life estimate; fentanyl and other exposures limit generalization.
BoundariesWhat this page cannot answer and where to continue
What this page does not answer
- It does not estimate impairment, intoxication, or fitness to drive.
- It does not predict urine, blood, saliva, or hair test results.
- It does not model repeated exposure, tolerance, withdrawal, or interactions.
- It does not replace clinician, pharmacist, toxicologist, or emergency guidance.
Continue with context
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- Clearance and volume of distribution
- Bioavailability, route, and formulation
- Active metabolites and parent compounds
- First-order vs nonlinear kinetics
- Detection windows vs half-life
- Reading labels and source quality
Read the medical disclaimer, methodology, and research standards before using the model for comparison.