Here in Vietnam it's completely impossible to get pseudoephedrine at all and I think it's the same in all Asian countries. I even resorted to trying to buy some ephedra tea (Chinese medicinal herb from which ephedrine was first discovered). I ordered a box of tea bags from Shopee.vn and rather amusingly received an envelope with the amount I had paid including shipping in cash and an apology letter saying they could no longer sell this herb and please don't leave a bad review.
However, a few months earlier due to a Google translate mixup where I thought I was ordering peppermint oil, I got 100ml of sassafras oil [0]. It's a precursor to MDMA and at least as restricted as pseudoephedrine.
just been banned in the UK. was the only thing that worked on my allergies.
edit: my bad, no it's codeine linctus that was banned, there was talk of making pseudoephedrine prescription only but that hasn't gone through.
It's readily available in Thailand and Indonesia. You can get it mixed with paracetamol OTC in Singapore, but almost everything in Singapore requires a prescription (even e.g. throat lozenges) so find a doctor if you're staying for a while. In Malaysia you need a prescription.