MDA half-life
The MDA curve is supported mainly by controlled MDMA studies in which MDA was measured as a metabolite.
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.
MDA: evidence and interpretation notes
What the representative value means
The MDA curve is supported mainly by controlled MDMA studies in which MDA was measured as a metabolite. That origin is stated plainly because administered MDA and metabolically formed MDA are not identical study designs.
The plotted input is 10 hours for MDA. It is a normalized comparison line, not a reconstruction of a measured blood concentration or a forecast of effects.
MDA is handled separately from MDMA because it has its own pharmacokinetic identity and can also appear as a metabolite in MDMA studies.
The 10 hour value makes MDA a longer entactogen-related curve than MDMA in this database. The model does not separate parent exposure from metabolite formation in any individual case.
The citations draw on MDMA/MDA plasma pharmacokinetic work, nonlinear pharmacokinetic research, and the direct MDA compound record.
This page does not provide use guidance or compare subjective effects.
For MDA, the curve should be read alongside the possibility of nonlinear kinetics, metabolites, physiologic stress, and delayed after-effects. The chart only follows the selected half-life input.
What each source contributes
- Kolbrich EA et al. Plasma pharmacokinetics of MDMA and metabolites including MDA (2008). This metabolism study identifies pathways, metabolites, or analytical targets and does not by itself create a complete human concentration-time curve.
- de la Torre R et al. Nonlinear pharmacokinetics of MDMA and MDA metabolite data (2012). This metabolism study identifies pathways, metabolites, or analytical targets and does not by itself create a complete human concentration-time curve.
- PubChem: 3,4-Methylenedioxyamphetamine. This identity record confirms names and compound identity and does not supply a human half-life.
For MDA, the numerical model is tied most closely to Kolbrich EA et al. Plasma pharmacokinetics of MDMA and metabolites including MDA (2008). As a metabolism study, it identifies pathways, metabolites, or analytical targets; it does not by itself create a complete human concentration-time curve.
Why there is no range on the chart
This profile plots 10 hours for MDA 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 10 h as a representative input for MDA. In the simplified model, about 18.9% remains after 24 hours and about 3% remains after five half-lives, or roughly 2.1 days.
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.
entactogen context
Entactogen pharmacokinetics can vary with dose, metabolism, temperature, co-exposures, and nonlinear features reported in some studies.
- The curve is not a safety or redosing guide.
- Physiologic effects can outlast or diverge from the parent-compound curve.
- Study context matters when comparing estimates.
ComparisonTimeline checkpoints and nearby profiles
MDA timeline checkpoints
| Elapsed time | Modeled remaining | Reading note |
|---|---|---|
| 12 h | 43.5% | Meaningful modeled decline, not near-zero |
| 24 h | 18.9% | Long-tail portion of the model |
| 2.0 days | 3.59% | Low modeled remainder, not a clearance guarantee |
| 3.0 days | 0.68% | Low modeled remainder, not a clearance guarantee |
| 5.0 days | 0.02% | Low modeled remainder, not a clearance guarantee |
Nearby profiles by half-life
These entries sit near MDA within the entactogen group when sorted by representative half-life. That makes them curve comparisons, not statements about equal potency, effects, or risk.
- MDMA (8 h)
EvidencePharmacokinetic inputs and source trail
Pharmacokinetics at a glance
| Representative half-life | 10 h |
|---|---|
| Curve type | Normalized, first-order decline |
Selection note: The MDA curve is supported mainly by controlled MDMA studies in which MDA was measured as a metabolite. That origin is stated plainly because administered MDA and metabolically formed MDA are not identical study designs.
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.
- Research abstract Kolbrich EA et al. Plasma pharmacokinetics of MDMA and metabolites including MDA (2008).Metabolism-focused evidence used to identify pathways or analytes. It does not automatically establish a population half-life.
- Full-text research de la Torre R et al. Nonlinear pharmacokinetics of MDMA and MDA metabolite data (2012).Metabolism-focused evidence used to identify pathways or analytes. It does not automatically establish a population half-life.
- Identity record PubChem Compound Summary: 3,4-Methylenedioxyamphetamine.Compound identity and naming record. It supplies chemistry context, not independent numerical support for the model.
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
- All substance profiles
- Browse the entactogen group
- Compare this curve
- 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.