Help for frizzy hair?

I have naturally straight (ish) hair. It has been coloured also. Everytime I curly my hair when a curling iron (I use a good brand GHD one also btw) my curls always drop and go frizzy! So frizzy especially at the top of my head. I always curl second day hair too and use pretty good products , heat protectant spray/oil etc. Can someone recommend me a good product that stops heat curled hair going frizzy! 

2017-04-11T00:37:33.809Z