That's a pretty serious dose and duration. Shutdown was pretty much inevitable.
One of the guys from AMS claimed that in many 6 to 8 week runs of their DHEA-based products they have blood work showing users only losing 25 to 50 percent of their natural testosterone in the worst cases of shutdown. I don't know the specifics, but I did read those claims.
I think of all the DHEA-based compounds, 1-DHEA is the harshest in terms of side effects. I've completely lost my sex drive, had zero energy and felt like I had the flu. I was also a raging dickhead. I don't know how it is, overall, for shutdown, but it's definitely a potent compound for being a DHEA metabolite.