Question: a client started bulletproof coffee last week. Ghee, collagen, brain octane. And says she is loving it but recently have had some headaches. Could the coffee cause this? Any experience with this?
All sorts of things can cause headaches, you might need to delve a bit deeper into their history to see what else might have changed.
Easy test - stop drinking the coffee for a day or two, see if the headaches stop.
Caffeine can both cause and relieve headaches. Try less caffeine or 50/50 with decaf, or Tea.