I started LDN in February in the hopes of modulating my immune system. My LLMD started me on 1.5mg and I titrated up to 4.5mg.
So far, the only noticeable difference is that my thyroid function improved somewhat (I've needed a lower dose of the T3 thyroid hormone replacement I take. However, I'm still taking a higher dose than what I was taking before my Lyme Dx).
The LDN website indicates that only certain compounding pharmacists produce quality LDN:
ldninfo.org/index.htm#How_can_I_obtain_LDN