Aleph-2, or ALEPH-2, also known as 2,5-dimethoxy-4-ethylthioamphetamine, is a serotonergic psychedelic of the phenethylamine, amphetamine, and DOx families.

According to Alexander Shulgin, its dosage is 4 to 8 mg orally and its duration is 8 to 16 hours. The drug is said to produce strong visuals.

Aleph-2 acts as a serotonin 5-HT₂ receptor agonist. The drug is also a weak monoamine oxidase inhibitor (MAOI), with IC₅₀Tooltip half-maximal inhibitory concentration values of 3,200 nM for monoamine oxidase A (MAO-A) and >100,000 nM for monoamine oxidase B (MAO-B). Aleph-2 produces anxiolytic effects in rodents.