How to convert white hair into black hair?

Look, you can't really 'convert' white hair back to black. Once the follicle stops producing colour, that's pretty much it. The pigment-making cell has retired for good. So, you can't permanently reverse it naturally.

Your most reliable bet is hair dye. It's a straightforward fix. You can get a professional job done at a salon for a top-notch result. Or you can just grab a box dye from somewhere like Chemist Warehouse.

Some people reckon certain vitamin deficiencies can cause premature greying. It might be worth a chat with your doctor about that. But for most of us, it's just a part of getting older. Honestly, dyeing is the only guaranteed way to get that black colour back.