Is this a Cryptogram?

[Robinson]

I have been working on this for some time. I am ready to give up.

Is it even a cryptogram?

ONNT-NPOY-NPNP.
NUNVNS-NRNV-NV.
NPNUNO-NRNR-NR.
NVNUNP-NP-NP.
NPNRNR-NQNO-NT-NU-NPNU-NPON.
NPNRNR-OY-NV.
NQNO-NQNQ-NU.

Anybody that can solve it and tell me how, would allow me to grow some of my hair back.

Thanks