Keratin treatment specialist wanted!!!

Hello there

I heard that keratin treatment is mostly for curly dry hair. I used to have straight, smooth, shinny hair, never had problems with splitting ends but the texture has changed with age. Now I have dry, thin, frizzy, dull looking hair. I have tried moisturizing stuff, deep hair conditioner, some hair cream and butter, olive oil and so on. It's all make my hair looks flat and greasy. I have oily hair normally but now it's only near the scalp and the rest is dry and tangling thin hair. I would like to know if keratin treatment can help a bit to bring some healthy look to it? Thank you