A good makeup artist can take your headshots to a whole other level, so a makeup artist is highly recommended for actor headshots and portrait photography.
The makeup artist will remain for the duration of your headshot session.
Check out these articles from Backstage.com on make-up for headshots:
http://goo.gl/T6Ah16“>How to Wear Makeup for Your Next Headshot Session
http://goo.gl/vtqCAA“>How to Communicate (and Collaborate) With Your Headshot Makeup Artist
Why you should consider a makeup artist for your headshots: