Can I use hair products like Kérastase Nutritive day cream after a Brazilian blow dry?

Depending on what product your salon used to perform the Keratin Treatment will reflect the answer your looking for as some brands rely on after care products by that brand due to the mildness of the product though with most treatments using creams and oils as you would normally is perfectly fine.
The best advice i can give you is to contact the salon you had the treatment with and find out the product they used as they should??? be fully trained by the brand to perform this kind of work and know all the ins and outs of the product/s there using and therefor be able to give you the correct advice, though in by professional this information should have been given to you at the time of the treatment?
Hope this advice has been helpful
Dominic @ CARLOS LONDON Hairdressing

USe lorea'l karaitin Treatment, use it once a week after shampoo then use after 10 minutes
then blow dry as normal once you have rinsed your hair thouroughly.