Why Does Botox Make My Forehead Look Shiny?

For some reason, my forehead always looks a bit shiny after a treatment of Botox. Any idea why? I don't love having a sheen. I want my face to not look oily. Any tips? 

SaraJ71

F, 48, New York

Some people claim Botox impacts the sebaceous (oil) glands on your face, resulting in more oil being produced, giving you a 'shiny' look. Others claim Botox does not impact the the sebaceous glands, and the shine is caused by your forehead smoothing out and light reflecting differently off of their forehead than they were previously used to. I have a friend who is pharma rep and doctors tell her that they too have seen Botox cause a shiny forehead. She was told that Dysport, a Botox competitor, gives you smooth skin without the shiny forehead. I have personally never had Dysport injected into my forehead, so I can't vouch for that. Using an oil-free foundation may also help.