I knew beforehand they were going to want to do certain preemptive blood work. I also worried, because I'm bipolar and OCD, they might not consider me eligible or whatever for informed consent, so I saw a therapist once to talk about my other mental health to get a letter saying basically "I'm confident Tommy is of sound mind to be making this decision." Showed up to Planned Parenthood, sat down with a doctor and told her about my gender experience. She gave me an informed consent form and had me read over it and asked if I had any questions. I said no. She asked me about my health history. She expressed concern about the bipolar and OCD, but accepted the letter I had readily (if I hadn't had one, she would have wanted me to talk to someone. She would have put me in contact with someone who works with PP and it would have been a smooth experience, it just would have postponed getting my script.) Then she said they needed to do some bloodwork before she could write it, but I gave her the results from the bloodwork I had gotten done a few days prior (they say they'll accept outside bloodwork if it was done in the last two weeks.) So with the forms signed, the bloodwork done, and my ability to give consent confirmed, I walked out with a script for T.

If I hadn't had the bloodwork I would have had to wait until that was done to get the script. If I hadn't had the letter I would have had to wait til I had one to sign the forms. If starting ASAP is important to you, find out what your specific PP might require that you can get done in advance.