Your portrait is developing beautifully @JonatanL! You’ve achieved the vast majority of realism in the head. Only the last 10% polish is left, which is a big accomplishment!
My first impression aligns with Omar that the skin is a bit shiny / sweaty. I bounce around a few ways to affect this:
- Bumping up the specular roughness value.
- Lowering the specular amount (IOR Level)
- Increasing the bump value
My only other note is the outside corner of the eye:

Yours is rounded where it’s characteristically a sharper corner. Between the eyelashes converging and the distinction of upper eyelid overhanging the lower, sharp is what you want:

Even when the eye is opened wider the eyelashes keep a distinct sharpness on the outside:

Usually the upper and lower eyelids are distinctly overlapped compared to yours which show no distinction on the outside corner:
