I've never had a problem traveling with supplements. I have flown a ton this year (including internationally) and I just put them in a supplement/pill case. I have one of those cases with every day of the week marked on there, and I use each compartment to separate the different supplements. The only time I've ever had a problem is when I packed a bottle of MSM. They just did a bag check and a test to confirm it wasn't cocaine haha.

you shouldn't have any issues unless you are bring in huge amounts that look like for resale purpose, then they'd have issue with you....I wouldn't worry about it nor declare them, you'll just call unnecessary attention to yourself. Pack them, don't carry more than a few days on you.

You probably can try and google to see if any of them fall under the illegal drug lists (I believe sudafed and poppy seeds are illegal in Asia), just to be safe.

I've never had any problem traveling with supplements. I've even gone through customs with little zip-lock baggies filled with vanilla protein powder, lol. usually I just put my pill form supplements in a single dob kit. You should be fine.

I've flown to London a few times with supplements in their original bottles, and other times in a spare pill separator that left about 8 kinds unmarked. No questions or issues, however it was also in my check-in bag, not my carry on.