I contacted VipMed for a set of extensive tests for men over 40. They recommended the Koc American Hospital in Istanbul, which I also chose. The whole process is extremely simple and goes smoothly, without bureaucracy, without complicated contracts and NDAs. VipMed took care of the entire travel logistics (plane, hotel, transfers), which saved me a lot of time and energy and gave me the peace of mind to focus on the tests. At the hospital, I was guided and assisted by a translator (Romanian-Turkish, employed by the hospital) who organized the entire logistics of the tests, went with me to all the tests, and interpreted the results. Of course, you can also discuss in English with the doctors, but I preferred not to risk misunderstandings.
Everything lasted three days, of which about 2.5 days were allocated to tests and investigations (biological samples, ultrasounds, X-rays, endoscopy, etc.), and half a day allocated to the interpretation of the results by specialist doctors (cardiology, gastroenterology, neurology, urology, diet, dermatology, etc.). In the end, I received the prescriptions and the diet to be followed until the next check-up. I bought the prescriptions from the pharmacy across the street from the hospital (I checked, and all the medicines are either available in Romania or there is an equivalent). The tests went one after the other, with a maximum of 30 minutes waiting between them, for about seven hours a day.
I would like to mention a few aspects related to the price. The cost of the trip itself depends on how much you want to optimize costs: you can choose hotels between 50 Euro/night and 220 Euro/night, you can buy a round-trip ticket or an open return ticket, you can stay exactly 3 days or extend your stay in Istanbul by a few days. I personally preferred to stay a whole week, to take the time to savor Istanbul. The cost of the investigations is only apparently higher than in Romania. In reality, if you quantify the time spent in traffic, the stress in the hospital hallways, the waiting for the availability of some doctors or machines, searching for experienced doctors to interpret the results, you realize that it is possible that in Romania, it will cost you twice as much. The cost of medication depends probably on the condition, the treatment; in my case, it was not expensive.
That's about all I had to say. I wish you all the best, and may you be able to help all those in need.