I haven’t gotten to research but I think this is a preventative Measure
I only gave 4 stars just because I can’t honestly say I’ve noticed a difference in anything possibly better hair growth and thickness but that could be do to my hairs own growth cycle. But it was delivered on time, and I also think its doing more preventative Measure things so I will be purchasing another bottle to see if I notice anything more and to see if my hair thickens up and says like this to know if it’s the vitamin or my own growth cycle :)
Rating: 4 stars