Medicines

From my cursory search, you need a medical certificate for at least, the diabetic medication and equipment. I also read that many OTC meds, even Tylenol or acetiminophen is restricted.....unless uou have a certificate that says you must have it. As a solo traveler, I like to have meds on hand, as I may not be well enough to get to a pharmacy, but it looks like 'just in case' may not work here. If you must use certain brands because of past adverse reactions, then they could add that to your diabetic certificate.

If you are not as concerned about sticking to your name brand, this article gives you alternate names for our favourite OTC meds https://www.silkroadmoments.com/post/the-beginner-s-guide-to-pharmacies-in-turkey
I have learned to trust foreign pharmacists and often their medications are more efficatious for the local 'bugs' that ours...that we may hsve developed some intolerance to. They have been able to prescribe and dispense meds for decades, unlike much of North America where it all has to go through a doctor first. Check, but many cities also have a rota of English speaking pharmacists on call and often on websites, but google translate app does wonders for translating symptoms.
All that being said, I am sure I had a first aid kit and mini pharmacy in my luggage when I was in Istanbul after viaiting Africa, and not asked anything about the contents.

How do I get a certificate? I senr emails to the Turkish embassy, counselate and customs web site and I have not received a response

I would bring any prescription medicines and medical equipment (needles, syringes and so on) in their original packages, and make sure you have a copy of your prescriptions. Same thing with Tylenol and so on - ordinarily I would say to put them in zip lock bags and just label them, but with Turkey, I would probably be more cautious and carry them in the original containers. You might try looking for the small travel containers of acetaminophen and other meds, though.

There was one website I found that said something about a medical certificate, but I was checking on Trip Advisor and other places, and everyplace else said just keep them in the original packages and carry a copy of your prescription with you. I think you'll be fine.

You would get the medical certificate from your doctor or travel clinic...from home, not from Turkey or representative. If you are willing to give up the non allowed OTC meds, then the printed prescription and labels should suffice.
Also, always take a spare prescription for your meds in case uou need a refill there.

Maria, I'm not sure if the OP is from the US or Canada, but I have never of a medical certificate here, and I don't think a doctor would have any idea what that refers to. I would think that a regular prescription from the doctor would be about the same thing.

ETA: I just checked with my daughter, who is a Physician Assistant, and she said medical certificates here in the states are for for people like pilots and licensed occupations who need clearance from a physician to fly or do what they need to do. I don't think a regular person could get one just to travel. But I do think that if you are concerned, you could get a letter from your doctor or a certified copy of your medical records. That said, I think just have the prescriptions with you would be enough, but if you're worried, ask your doctor for a letter. :)

@Mardee, I hear what you are saying, but a 'certificate' doesn't need to be a specific form. However, if one insists to take illegal OTCs into the country, then there should be a doctor's signed document as to the need to carry and use it. The chances may be slim that you are asked, but it clearly states even acetominophen and numerous cold remedies are not legal in Turkey and requires "a medical certificate" so as a CYA, one may want documentation/certificate/whatever, stating why they 'need' to carry them. A letterhead or printed RX with list of meds and doctor's signature should suffice.
I am aware a document means an appointment and most likely a fee. Alternatively you play dumb when asked. And I noted, I was never asked, but YMMV.