# 3,4-Methylenedioxyamphetamine
**3,4-Methylenedioxyamphetamine** (MDA) is a ring-substituted amphetamine derivative with the formula C₁₀H₁₃NO₂ that acts as a releasing agent of serotonin, norepinephrine, and dopamine in the brain, producing stimulant, empathogenic, and psychedelic effects.[1](https://pubchem.ncbi.nlm.nih.gov/compound/1614) • [2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) It is the N-demethylated analog of MDMA (3,4-methylenedioxymethamphetamine, ecstasy) and is itself a minor but psychoactive metabolite of MDMA in humans.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) MDA is a Schedule I controlled substance in the United States.[3](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562)
| Key fact | Detail |
|---|---|
| Chemical formula | C₁₀H₁₃NO₂ (PubChem CID 1614)[1](https://pubchem.ncbi.nlm.nih.gov/compound/1614) |
| Mechanism | Releases serotonin, norepinephrine, and dopamine; greater dopamine-to-serotonin ratio than MDMA[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) |
| Psychedelic component | Serotonin 5-HT₂A receptor agonist with 10-fold higher activation potency at this receptor than MDMA[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) |
| Human half-life | Plasma elimination half-life 8.4 h (geometric mean) at 92 mg, versus 7.3 h for 100 mg MDMA[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) |
| Effect duration | 6.1 ± 0.5 h for "any drug effects" versus 4.1 ± 0.4 h for MDMA at equimolar doses[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) |
| Legal status | Listed in the original scheduling of the Comprehensive Drug Abuse Prevention and Control Act of 1970, as the first entry of Schedule I subtitle "Hallucinogenic Substances"[3](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562) |
| Relation to MDMA | Minor active metabolite of MDMA in humans[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) |
## Chemistry and pharmacology
MDA is an amphetamine molecule bearing a 3,4-methylenedioxy ring substitution, the same scaffold as MDMA, MDE, and related entactogens.[1](https://pubchem.ncbi.nlm.nih.gov/compound/1614) • [4](https://www.sciencedirect.com/science/article/pii/0304394088906581) Like MDMA, it mainly releases the monoamines serotonin, norepinephrine, and dopamine through transporter-mediated mechanisms.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) Early biochemical work noted that, despite structural similarity to psychedelic phenethylamines such as mescaline and DOM, the class showed a unique insensitivity to N-methylation and stereoselectivity that indicated a mechanism distinct from simple activation of serotonin receptors.[5](https://pmc.ncbi.nlm.nih.gov/articles/PMC12873472/)
MDA differs from MDMA in two pharmacological respects that shape its subjective profile. It exhibits a greater dopamine-to-serotonin release ratio, which suggests more stimulant-like acute effects, and it is a 5-HT₂A receptor agonist with 10-fold higher activation potency at that receptor than MDMA, the mechanism through which classical serotonergic psychedelics produce their subjective effects.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) In human cortex binding studies, racemic MDA displayed its highest affinity, approximately 1 µM, for the "DOB binding site" labeled by a brominated DOB ligand, and moderate affinity of 4–5 µM for the 5-HT₁A, 5-HT₁D, and α₂-adrenergic sites.[4](https://www.sciencedirect.com/science/article/pii/0304394088906581)
## History
The methylenedioxy amphetamines trace to the pharmaceutical company Merck, whose chemists synthesized the class while searching for a synthesis of the blood-clotting agent hydrastinine; MDA itself had no medical significance in that work, and Merck's chemists resynthesized it a few times for specific purposes and conducted animal experiments without discovering its effects on humans.[6](https://academic.oup.com/book/46625/chapter-abstract/410051253?login=false) An Erowid timeline records that on January 8, 1953, Harold Blauer died of an overdose of MDA, under the army code name EA-1298, during an army-sponsored drug experiment.[7](https://www.erowid.org/chemicals/mda/mda_timeline.php)
**Psychotherapy era.** Research in the 1960s identified MDA as an apparently effective facilitator of psychotherapy, in work cited as Naranjo et al., 1967, making it a predecessor to MDMA in that role.[5](https://pmc.ncbi.nlm.nih.gov/articles/PMC12873472/) MDA first gained popularity as a recreational drug in the San Francisco, California area around 1967.[3](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562) Its recreational rise was short-lived in legal terms: it was listed in the original scheduling of the Comprehensive Drug Abuse Prevention and Control Act of 1970, as the first entry of Schedule I subtitle "Hallucinogenic Substances".[3](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562) A forensic report also documents clandestine synthesis, identifying the unusual precursor α-methyl-3,4-methylenedioxyphenylpropionamide (MMDPPA) in a putative clandestine laboratory making MDA.[3](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562)
## Effects in humans
Modern controlled studies have compared MDA directly with MDMA. A within-subjects, double-blind, placebo-controlled study of 1.4 mg/kg oral racemic MDA in 12 healthy volunteers found that MDA was well tolerated, induced robust increases in heart rate and blood pressure, and raised cortisol and prolactin to a similar degree as 1.5 mg/kg MDMA; MDA self-report effects shared features with MDMA as well as with classical psychedelics and lasted longer, remaining elevated at 8 h while MDMA effects resolved by 6 h.[8](https://pubmed.ncbi.nlm.nih.gov/30967099/) In that study, peak plasma concentration (Cmax) and area under the curve (AUC₀₋∞) were 229 ± 39 µg/L and 3636 ± 958 µg/L for MDA, with the metabolite 4-hydroxy-3-methoxyamphetamine (HMA) at 92 ± 61 and 1544 ± 741 µg/L.[8](https://pubmed.ncbi.nlm.nih.gov/30967099/)
A larger randomized, double-blind, placebo-controlled crossover trial in 23 healthy participants compared equimolar doses of MDMA (100 mg), MDA (92 mg), and the lysine-conjugated prodrugs Lys-MDMA (172 mg) and Lys-MDA (164 mg).[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) MDA produced stronger and longer-lasting subjective "any drug effects" than MDMA, with effect durations of 6.1 ± 0.5 versus 4.1 ± 0.4 h, and induced greater subjective stimulant effects, more negative "bad drug effects," more "fear," and more "visual alterations."[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) The plasma elimination half-lives were 8.4 h for MDA and 7.3 h for MDMA.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) Lys-MDA behaved as a functional slow-release prodrug, delaying onset and peak (1.1 ± 0.2 h and 3.0 ± 0.4 h versus 0.7 ± 0.1 h and 2.0 ± 0.1 h for MDA) while producing otherwise similar effects; Lys-MDMA, by contrast, released no detectable MDMA, likely because of its tertiary amine structure.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/) The authors concluded that these results highlight MDA's less favorable therapeutic profile relative to MDMA.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/)
MDA also appears as a metabolite in MDMA pharmacokinetics. After controlled oral administration of recreational 1.0 and 1.6 mg/kg MDMA doses in 50 volunteers, blood and plasma were quantified for MDMA and its metabolites HMMA, MDA, and HMA.[9](https://pubmed.ncbi.nlm.nih.gov/24232751/) In a repeated-dose study, taking MDMA twice 4 h apart raised MDA concentrations above single-dose expectations (+14.2% Cmax and +10.3% AUC), a pattern attributed to MDMA metabolic autoinhibition.[10](https://www.sciencedirect.com/science/article/pii/S0924977X15001637)
## Neurotoxicity
Animal studies show serotonergic neurotoxicity for both MDA and its N-methylated derivative. Two weeks after multiple 10 mg/kg doses of MDA or MDMA, selective and dramatic decreases were observed in regional brain tryptophan hydroxylase activity and in corresponding concentrations of serotonin (5-HT) and its primary metabolite 5-hydroxyindoleacetic acid (5-HIAA).[11](https://pubmed.ncbi.nlm.nih.gov/2883012/) Work on the metabolism of the (+)-enantiomers of MDA and MDMA found that their thioether conjugates stimulate acute release of serotonin, dopamine, and norepinephrine and produce a behavioral response commensurate with the "serotonin syndrome," implicating metabolism in the toxicity of these compounds.[12](https://pubmed.ncbi.nlm.nih.gov/15228153) PubChem summarizes both MDA and MDMA as neurotoxic analogs whose enantiomers induce synaptosomal release of serotonin and dopamine in vitro.[1](https://pubchem.ncbi.nlm.nih.gov/compound/1614)
## Legal status
In the United States, MDA is a Schedule I controlled substance. It was included in the original scheduling under the Comprehensive Drug Abuse Prevention and Control Act of 1970, as the first entry of Schedule I subtitle "Hallucinogenic Substances".[3](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562) A National Institute on Drug Abuse monograph notes that among the ring-substituted amphetamines commonly abused by humans, only MDA and MDMA maintained self-administration behavior in animal models, and that MDA, PMA, and MDMA have pharmacological properties distinct from other substituted amphetamines.[13](https://archives.nida.nih.gov/sites/default/files/monograph94.pdf)
## References
1. [3,4-Methylenedioxyamphetamine, C10H13NO2, CID 1614, PubChem](https://pubchem.ncbi.nlm.nih.gov/compound/1614)
2. [Straumann, I., Vizeli, P., Avedisian, I. et al. (2025). Acute effects of MDMA, MDA, lysine-MDMA, and lysine-MDA in a randomized, double-blind, placebo-controlled, crossover trial in healthy participants. Neuropsychopharmacology 51(2), 476–485.](https://pmc.ncbi.nlm.nih.gov/articles/PMC12708835/)
3. [An unusual clandestine laboratory synthesis of 3,4-methylenedioxyamphetamine (MDA), Forensic Science International](https://www.sciencedirect.com/science/article/abs/pii/S0379073812004562)
4. [Ring-substituted amphetamine interactions with neurotransmitter receptor binding sites in human cortex, Neuroscience Letters](https://www.sciencedirect.com/science/article/pii/0304394088906581)
5. [History, pharmacology and therapeutic mechanisms of 3,4-methylenedioxymethamphetamine (MDMA), PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC12873472/)
6. [The Early History of MDMA, Oxford Academic](https://academic.oup.com/book/46625/chapter-abstract/410051253?login=false)
7. [Erowid MDA Vault: Timeline](https://www.erowid.org/chemicals/mda/mda_timeline.php)
8. [Effects of the Psychedelic Amphetamine MDA (3,4-Methylenedioxyamphetamine) in Healthy Volunteers, PubMed](https://pubmed.ncbi.nlm.nih.gov/30967099/)
9. [3,4-Methylenedioxymethamphetamine (MDMA) and metabolites disposition in blood and plasma following controlled oral administration, PubMed](https://pubmed.ncbi.nlm.nih.gov/24232751/)
10. [Human pharmacology of MDMA after repeated doses taken 4 h apart, European Neuropsychopharmacology](https://www.sciencedirect.com/science/article/pii/S0924977X15001637)
11. [A comparison of the neurotoxic potential of methylenedioxyamphetamine (MDA) and its N-methylated and N-ethylated derivatives, European Journal of Pharmacology](https://pubmed.ncbi.nlm.nih.gov/2883012/)
12. [The role of metabolism in 3,4-(+)-methylenedioxyamphetamine and 3,4-(+)-methylenedioxymethamphetamine (ecstasy) toxicity, PubMed](https://pubmed.ncbi.nlm.nih.gov/15228153)
13. [Pharmacology, NIDA Research Monograph 94](https://archives.nida.nih.gov/sites/default/files/monograph94.pdf)
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*Topic: Encyclopedia › Physical world and mathematics › Chemistry › Organic substances › Amines and nitrogen functional groups › Psychoactive amine substance families › Substituted amphetamine families › Methylenedioxy- and ethylidenedioxy-amphetamines (MDxx)*
*Initially written Sep 17, 2026 · Reviewed: Sep 19, 2026; Sep 30, 2026; Oct 21, 2026 · Edited: Sep 19, 2026; Sep 30, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
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