Firsthand experience with Xanax and co-codamol - they didn't check. I asked where to show customs letter of prescription and they just waved me through. Same happened in Singapore and others. However, like you, I'm also cautious and chose Cyprus (intra-EU, no customs issues) over Egypt or Turkey this week for just this reason. I didn't want to go through the worry of taking the medications with me even though I know most likely it won't be checked out really considered if it's personal use. But there are always those scare media stories that make me never want to set foot in Dubai, for example, just in case.

But making sure of the prescription, checking on the Turkish customs website to see if you can get a letter of approval from them to bring in your medication (Singapore has this system), getting a written note from doctor as well as the prescription, + original boxes, are all likely to help with if not removing the issues entirely, make it more likely they will simply bin the medications and send you on your way rather than arrest you.

As you asked for first hand experience though, mine is that I was never asked, nor checked going through customs in Istanbul.

Turkey should in theory exit lockdown in a week or two and tourists now can still go to museums, stay at hotels etc. The bad side of things is that you can eat at restaurants (they're closed), or have a Turkish coffee (cafes also closed). In Cyprus it's more or less the same at the minute, but I stay in the hotel and I'm mostly here just for sun and working remotely, and you can get in the sea and drive around too (with a permission form from the hotel).

Best of luck with your trip!