Yes, make sure you use at least USP grade if you inguest it. Not USP reag. but USP. There are some supplier for methylene blue USP. I guess the best quality esp. inguestion you will find on ceretropic or nootropics-source.com. If you buy it bulk, from some supplier, it will less cheaper. But for inguestion, 10g at 60mg should last very long. For non inguestion I cant say exactly. But maybe USP reag. is good enought.