You can try regain which is available over the counter, but its pricey.
Also you can ask your doctor for propecia tablets, But they are not usually available on the NHS, so he would write you out a private prescription. I had a private prescription come into work for these recently, and they cost £92 for a 4 week supply, so it depends on how much you want to try and keep your hair! Also, neither pf these products are guaranteed to work. Like all medications, they work for some people, not others, so you may be wasting an awful lot of money.
Personally, I dont think you should fight nature. Shave it off - I would much rather see a guy confident with his shaven head than some sad old git with a desperate comb-over!
I work in a pharmacy and see so many blokes trying regain and propecia tablets, i just wanna tell themto forget it and go bald gracefully.
Women do not have a problem with bald men, or thinning hair, we really dont care.
Shave it off!
Im a pharmacy dispenser