5-methyltryptamine and  5-methoxytryptamine are part of the tryptamine family of chemicals. Like tryptamine itself, they interact with serotonin receptors in the brain, and are likely to influence mood and perception, but are rarely investigated. The current study examined whether these tryptamine derivatives altered cell viability of the brain-derived SH-SY5Y-cell line. This cell line is often used to model Parkinson’s disease as these cells share many features with dopamine neurons, such as generating enzymes that produce and breakdown dopamine. In this study, tryptamine, 5-methyltryptamine and  5-methoxytryptamine were each applied to SH-SY5Y cells separately (for 24 hours) at a range of concentrations (10 µM, 30 µM, 100 µM, 300 µM, 1 mM, 3 mM, and 10 mM). Cell variability was measured using the widely used MTT assay, where MTT by-product is proportional to the number of viable, metabolically active cells. Compared to vehicle-control, it was found that tryptamine had no effect on MTT at low concentrations, but MTT was reduced at high concentrations (3mM and 10mM), and thus tryptamine was neurotoxic. In contrast, both 5-methyltryptamine and  5-methoxytryptamine both increased MTT at low concentrations (10 uM and 30 uM) and thus increased cell viability (and were also toxic to cells at high concentrations). Thus, this study demonstrated for the first time that 5-methyltryptamine and  5-methoxytryptamine increase cell viability, and may therefore be neuroprotective of dopamine neurons and possibly serve as a treatment for Parkinson’s disease.