score:6
In Bangkok, 7-Eleven are open 24 hrs and inside there is usually a pharmacy section where you can buy over the counter medication. However, you shouldn't call them drugstore as people may misperceive that you are looking for drugs lol.
Typically hospital pharmacies are quite a bit more expensive but may legally sell some drugs with restricted access. Some street pharmacies will sell those illegally but if they are willing to break the law on that, how do you know they are not selling equally illegal fake medicine?
On the streets you will see people selling viagra, valium, etc but be careful and use good judgement. Don't buy or do drugs in discotheques. It's not worth it if you get caught.
Upvote:2
Interesting answer from Vovicon on https://redd.it/hh3hij, pointing out one can look at street view/pictures to try to spot a 24 hour open sign (and hope that the opening hours are still accurate: calling the business, if their phone number is disclosed somewhere, might be a good idea to confirm):
[...] businesses here are still very bad at updating their listings on Google maps (on more generally online). [...]There's a franchise called"Bangkok Drugstores" which has many branches and seem to maintain their Google listings better. You can see for example this one is listed as 24h and just checking street view/pictures you can see it says "24h" on their main signage: https://maps.app.goo.gl/E7HrPGsGom4BR58T7
We can indeed see a 24 red sign on the entrance door:
Another example of a drugstore that is open 24 hours in Bangkok?: JC Pharma:
It'd still be more convenient to have a centralized, up-to-date list of drugstores with their business hours/days instead of having to manually spot "24" on the images (or Google or others could help by deploying some text detection algorithms to automatically extract business hours).