Minoxidil and finasteride will prevent further hair loss and thicken up what you still have. I highly recommend them.
Finasteride is a hormone based therapy which prohibits the production of DHT which strangles hair follicles, but it can effect male reproductive health so I recommend taking it typically instead of orally to prevent systemic exposure.
I have been using a combo spray for almost a year with great results.
Helium by volume is lighter than air. That metric is called density.
So if you displace the volume in your lungs with helium that weighs less than the air that’s usually there, you will weigh less.
Physics!