Acute effects of MDMA, MDA, lysine-MDMA, and lysine-MDA in a randomized, double-blind, placebo-controlled, crossover trial in healthy participants.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology January 1, 2026 Isabelle Straumann, Patrick Vizeli, Isidora Avedisian et al. 5 citations
In a double-blind, placebo-controlled crossover trial with 23 healthy adults, the acute effects of MDMA, its metabolite MDA, and two lysine-conjugated prodrugs were compared. MDA produced stronger and longer-lasting subjective drug effects (6.1 vs. 4.1 hours), greater stimulant effects, more negative effects, fear, and visual alterations than MDMA at equimolar doses. The lysine-conjugated prodrug of MDA (Lys-MDA) delayed the onset and peak of effects but otherwise acted similarly to MDA. Lys-MDMA did not release MDMA into the blood and produced no effects, indicating it is not a functional prodrug. The findings suggest MDA has a less favorable therapeutic profile than MDMA, and lysine conjugation can modulate the timing but not necessarily improve tolerability of effects.