Can PRP be effective for forehead lines instead of Botox? And crows feet lines. Is it safe to inject the forehead area?

PRP can be used like a filler.  It will stimulate growth of new tissue and blood vessels in the areas injected.  If there are static lines present when there is no facial expression being displayed, filler is used to plump the lines and stimulate collagen so PRP may be used instead.  In the forehead especially as we age Botox has to be injected sparingly to prevent the brows and/or eyelids from drooping.  In this case PRP can be used to soften the static lines of the forehead and crows feet.  However, with facial expression like eyebrow elevation, smiling or squinting, the lines are due to muscle contraction so a Botox or similar product would still need to be injected to relax the muscle activity producing these lines at rest and with motion and to prevent them from becoming deeper.  

The effect is qute different.  Botox inactivates the nerves that allow muscles to contract.  The smoothing effect is the inability of the nerves in the treated area to perform their function

PRP consists of growth factors that cause the tissueto regenerate.  It may thicken the underlying tissues somewhat and healskin defects.  It is more of a "polish" for the skin surface.  There will be some slight filling in of wrinkles, but tha tis not the main use for PRP.

The real answer is not either or, but both.  We use Botox in its designated areas, the glabella, forehead and crows eyes.  We can then treat the same areas with PRP.  I like waiting 4 weeks between session.  We are then left with a synergistic effect. (1 +14 not 2)