Kelly, I hope LDN helps to hold your friend's ALS back for a long while, but it will not stop it. I believe it did slow my friend's ALS, for 6 years, but alas he did pass away this year..he was only in his 40s..
ALS is not the same as MS, it's a muscle disease and deadly. But like you said, it cannot hurt and just may help him. I will pray every day, that it does..