DMT and Melatonin are almost identical on a molecular level, only differentiated by one Co2 molecule. So in other words Melatonin - Co2 = DMT.
Both are synthesized in the human body from the amino acid Tryptophan, as well as serotonin.
Practices like deep pranayama breathing, fasting, and very intense exercise all decrease Co2 levels in the blood, while also increasing levels of serotonin and melatonin in the body.
Is it a coincidence that ancient yogic supernatural powers and miracles are all associated with these practices and this also happens to be an alchemical recipe that seemingly would convert endogenous melatonin into DMT? By decreasing levels of Co2 while simultaneously increasing serotonin and melatonin?
The effect of endogenous DMT is a lot more subtle then plant-derived DMT but similiar. I would not suggest taking melatonin supplements because it will limit your ability to create your own. I would suggest however a good quality tryptophan supplement combined with pranayama and intense Yoga in a darkroom. This will absolutely cause DMT like effects overtime, depending on how well your body naturally manufactures its own Melatonin. I believe these DMT like effects can be created outside of the dark also.