Divine Herbal

Hello Everyone,
I have purchased Divine Herbal oil for hair growth just 2 days ago. I applied to my scalp and washed my head in the morning. IF I DON'T WASH IN THE MORNING AND HAVE SHOWER IN THE EVENING ARE THERE ANY SIDE EFFECTS?. I had shower this morning and now I have neck pain. I knew this will happen. Can anyone help me Please.

Regards,

JOE