If you are thinking of injecting or ingesting Methylene blue read the following...
Gosselin et al. have given methylene blue a toxicity rating of 4 [Gosselin, et al., 1984]. Acute exposure to methylene blue by intravenous injection has been found to cause hypertension, sweating, chest pain, confusion, nausea, vomiting, dizziness, and cyanosis, as well as urine and stool discoloration [Arena, 1986; Gennaro, 1985].
Large, oral doses of methylene blue may cause fever [McEvoy, 1989]. Methylene blue has also been reported to cause quadriplegia after intrathecal injection [Driesbach, 1980]. Subcutaneous injection of methylene blue may cause necrotic abscesses [Reynolds and Prasad, 1989].
Methylene blue induces hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G-6-PD) enzyme deficiency. Dark-skinned races have a higher incidence of methylene blue-induced hemolytic anemia than lighter skinned races, but the disease has not been noted in North American Indians or Eskimos [Thienes and Haley, 1972].
Methylene blue is a severe eye irritant [Lenga, 1988]. High concentrations of methylene blue have been found to induce corneal and conjunctival injury [Grant, 1986].
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