If you could “cure’ baldness, you would be a billionaire. You wouldn’t even have to spend much money marketing the product. It would sell itself. There is such a huge consumer demand and people already spend billions of dollars a year on products that (for most people) do not work.
The reality is that it’s highly unlikely that any topical baldness treatment will work. The body is just too complicated and the reasons for hair loss is due to hair follicle cells ceasing to work. Any topical treatment would have to penetrate the skin (unlikely) and somehow revive cells that aren’t working any more. The cells are most likely permanently turned off so even if you could get the product to the cells, it’s unlikely to have much effect.
However, this type of technology is more promising. Researchers at the University of Pennsylvania have managed to convert adult cells into epithelia stem cells. If this type of technology could be developed into a full-blown treatment the way it would work is that scientists would take a cell sample from somewhere in your body, grow them up into a full colony, convert them to hair stem cells and transplant them where you want hair.
Not a cosmetic for sure, but a potential “cure” for baldness.