Griffiths, 23, who signed for Celtic last month and made his first start for his new club against St Johnstone, has joined Stokes, 25, in advertising the firm in a bid to reverse his receding hairline.
Stokes convinced Griffiths to join Glasgow firm KLS Hair after promoting the clinic on Twitter.
Griffiths said: “I’ve been thinking about this for some time now and thought now is as good a time as ever to get it sorted.
“It’s only started to become more noticeable in the past two years, so I thought it was time to do something about it. I believe KSL Hair are the team to sort this issue once and for all for me. They understand what you’re going through.
“Really looking forward to my results at the end of this season, on and off the pitch.”
Singer Sir Elton John, Manchester United footballer Wayne Rooney and actor James Nesbitt are among a string of celebrities who have undergone hair regeneration procedures.