Before answering, let me add an unsolicited comment. No one under 22 should consider taking this compound, since a person's endocrine system is not fully developed until that age (give or take a year). M 1-T has a very strong effect on the endocrine system and could cause damage to a system that has not yet fully developed.
Although I have not read every report, in the early days (a whole 9 months ago), it seemed that there was a difference between brands. That may or may not be the case any longer. The problem is that this compound is made in another country, perhaps by several different sources. Therefore, not every batch is made using the same controls, purity, etc. I would recommend that people purchase a product from one of the board sponsors to increase the likelihood of getting a quality product.