I totally agree with Dr Chua that PRP has very little evidence published in the medical literature suggesting its indication for hair loss treatment. Furthermore, it’s banned in SG for aesthetic purposes.
You should visit aesthetic doctors or dermatologists highly interested in treating hair loss to get a detailed consultation, diagnosis, and treatment options.
There are two ways to restore hair in your case (and for many other men):
1. Hair Transplantion
It's the most effective method to restore hair, as strong hair follicles from the back of the head are extracted one by one and then re-implanted on the front and top of the scalp. These follicles will never be subject to balding (notice how some old men still retain the U shape hairstyle around the sides and back of their head despite the top being empty?) It is the only method to put more hair follicles into your scalp.
2. Medical hair treatment
Finasteride blocks the hormone DHT responsible for hair loss, and is recommended for oral usage (3% of users may have some sexual side effects). It makes existing hair follicles thick and strong again.
Minoxidil increases blood flow to the scalp, and encourages hair growth.
Low level laser therapy also stimulates growth and strengthening of existing hair follicles. In summary, it is best to perform a hair transplant, and then maintain the hair follicles (old and new ) with the medical treatments listed.
In Singapore, Manual Hair Transplant costs $5-8/graft and ARTAS ROBOTIC Hair Transplant costs $8.5-$10.50/graft. Once again, do visit a doctor for a detailed consultation as not all the options listed may be suitable for you.
You can read this article for more information about hair loss treatment in Singapore.