  Non-Standard Interactions (NSI) of neutrinos may originate from models in
which new particles interact with neutrinos. In scalar extensions of the SM,
the typical approach to obtain NSI requires Fierz transformations and charged
Higgses, which suffer from strong constraints from collider searches or charged
lepton flavor violation processes. We propose here an alternative approach to
generate NSI, namely via loop processes. We show that such loop-induced NSI
from secret neutrino interactions can reach sizes of ${\cal O}(0.1\sim1)$
compared to standard Fermi interaction. This approach can also give rise to
neutrino-quark NSI.
