These side effects occur in extremely high doses, much much higher than the effective dosage.

It doesn't need to be administered intravenously (only for methemoglobenia) - although more effective that way.

serotonin syndrome, rbc breakdown and allergic reactions occur when you drink a glass of what few drops are enough.

As said, it is extremely safe drug in low dosages (4-16 drops of 0.1% solution).

Edit: Also see the Kevin Rose Show episode https://podcast.kevinrose.com/dr-peter-attia-longevity-compo... starting @ 1:16:20