I tried this as a free sample thank god cause it was such a nightmare. Now, I'm always really careful with any new skin stuff so I used way less than the instructions, less than once a day, just the teeny tiniest bit over certain parts of my face, and I still ended up with the worst chemical burn. It was horrible.
My skin can be a bit sensitive and normally stay away from this stuff anyway, but this still seemed excessive. A week of this and it was month before my face stopped hurting.
I like many of Hourglass' products, but this primer could have been much better (and less expensive at $60 for one ounce). It's a fairly basic primer with oil, cyclopentasiloxane and other silicons for slip. It doesn't help my makeup last longer, and I would put out a warning for those with oily or breakout-prone skin. As a self-tanner it's adequate, but very easy to overdue as it is totally clear and goes under your makeup. The first time I wore it, though I used a very light hand I wound up with an embarrassingly orange-brown face halfway through a day at the office. After playing around with it a little more I've found it gives a pretty natural result if I put a small dot on a cotton round first, and work it into my face that way (though that way you don't use enough to properly prime skin for makeup). It's okay, but the ingredients and cost make it a no for me.