Took the time to take some screenshots from each episode, and here they are.

Janeway's Hairstyles, Season One: A Thread

These are in airing order, which may differ from production order.

I'm no hair expert, so forgive me if some terms are incorrect.
#StarTrek #StarTrekVoyager

Episode One: Caretaker
The curls in the back do not appear again, unfortunately.

Episode Two: Parallax
The curls have transformed into a wide bun.

Episode Three: Time and Again
The bun is tighter and narrower, and the hair is bulkier.

Episode Four: Phage
Bun is wide again, hair still bulky.

Episode Five: The Cloud
Much the same; underside of the bun is styled lightly different.

Episode Six: Eye of the Needle
The bun is rolled now.

Episode Seven: Ex Post Facto
Bun is rolled slightly differently, or it may be the angle.

Episode Eight: Emanations
I couldn't get a clear screenshot of the back directly, but this still works.

The bun is styled different again, and looks more complex.

Episode Nine: Prime Factors
Looks much the same, but the dark scene makes it harder to tell.

Episode Ten: State of Flux
The complex bun is replaced by a wide one, I think it's rolled. Hair in front is less voluminous.

Episode Eleven: Heroes and Demons
Massive change. The bun is gone, and instead the hair is pulled tightly back. Reminds me of Seven's hairstyle later on.

Episode Twelve: Cathexis
The same hairstyle is kept for one more episode.

Episode Thirteen: Faces
This one didn't feature Janeway as much, so there weren't many good shots.

The wide, rolled bun is back.

Fourteen: Jetrel
Mostly the same, bun might be a bit larger?

Episode Fifteen: Learning Curve
Also not Janeway-heavy, and there wasn't a single scene with her facing away.

Is that a double-rolled bun?

Whew. I've been wanting to make this thread for a while now. It seems there were small changes in every episode. I might go season 2 later on...