Does PRP actually regrow thinning hair
PRP for thinning hair arrives with a tidy headline: your own plasma, injected into the scalp, with little in the way of side effects. Tidy headlines are exactly where a complicated situation starts asking questions.
For a reader in Ypsilanti, the first question is about the wider field. ASPS poses it in a page on which hair loss treatments are available for women, and it is a sensible frame before you commit to any single option.
What the headline actually says
health.clevelandclinic.org states that PRP therapy works to regrow lost hair with minimal side effects by injecting your own plasma into areas of your scalp. That sentence describes a method and how well it is tolerated. It does not describe what your scalp will do.

Where the numbers land
The clinician cited by health.clevelandclinic.org reports that, after the time frame given there, most people, both male and female, have regrown thirty to forty percent of the hair they've lost. Read that as partial regrowth reported by one clinician. It is not a promise of full restoration.
For the procedure in outline, see the Cleveland Clinic page on PRP therapy.
The constraints, in the order they bite
Three questions arrive in sequence. How much hair have you lost, and how much partial regrowth would count as a success? How long can you wait for a result, given that the reported figure is tied to a time frame? And are injections the right category of treatment for your situation at all?
Each answer narrows the next one.
When injections are the wrong category
Cleveland Clinic also publishes a page on hair replacement surgery, which sits in a different category from injections. If your constraints point that way, compare the two on their own terms instead of treating PRP as a softer version of surgery.
The compromise the sources support
Take it as a documented option with minimal reported side effects and partial reported regrowth. Judge it on those terms, and set your expectations to the reported range rather than to the best case you have imagined.
The caveat that stays attached
For the research side, the PMC review Platelet-Rich Plasma in Aesthetic Dermatology: Current Evidence and Future Directions is the place to read further.
Whether any of this applies to your scalp is a question for a clinician who can examine you.