Illegal over the counter drugs?

I'm moving to Japan and I might want to bring some medicine with me.

Are any specific popular American medicines illegal? I heard that Sudafed is... so what cold medicine that actually works can I bring!?

I'll need Unisom too for sleeping...

As far as I can look up, the effective ingredient in Unisom is Diphenhydramine HCl, which is the same substance used in Drewell sold in Japan (sleep inducing tablet), so that would be no problem.

Bring whatever OTC drugs you can! It is very difficult to find alternatives and other options without having them mailed from the US and having them go through customs and potential problems. I have lived in Tokyo for 2 years.

Especially Sudafed (and Unisom probably, too).

anything with codine (pain killer) or for that matter, most pain killers (OTC or not) are no-no's here.

I would bring cold medicine and allergy medicine. Yes they have such things here, but IMO, totally useless unless you want to be a spaced out zombie....

My understanding is that it's fine to bring OTC medicines, such as Sudafed, into Japan with you as long as they are for personal use during your stay. If you're carrying a reasonable quantity (a box or two), there shouldn't be an issue. I bring what medicine (things like benadryl, cold medicine, immodium) I use from the US each time I return for business or to visit family (once or twice a year) and have never been asked about it. I think the issue is with buying or selling these medications within Japan, not just with posessing them.

Blimey, I heard you can't bring some medicines to Japan, but what I read makes me really worried. Is there any list where you can check which substances are banned? I hope ibuprofen is ok, but how about drotaverine? I also need to take vitamin D and, although I suppose I can get it in Japan as well, I'm bringing about 4 months supply, just in case. These are all OTCs, but what if they find those and think it's something illegal and deport me?

Ask your nearest embassy or consulate.
Four months supply will look like a lot, especially as a tourist permit in Japan is for 3 months. Are you coming here on a longer term visa, or can you show proof that you will be travelling elsewhere as well?

Of course Vitamin D is available here.

I'm coming for a year. And I'm often allergic to medicines and stuff, so I don't really like experiencing much... How about if my family sends me some more? But then again, they might open the parcel at customs and don't like what they find. It's so confusing. :(