  We demonstrate how weak hybridization can lead to apparent heavy doping of 2d
materials even in case of physisorptive binding. Combining ab-intio
calculations and a generic model we show that strong reshaping of Fermi
surfaces and changes in Fermi volumes on the order of several 10$\%$ can arise
without actual charge transfer. This pseudodoping mechanism is very generically
effective in metallic 2d materials either weakly absored to metallic substrates
or embedded in vertical heterostructures. It can explain strong apparent doping
of TaS2 on Au (111) observed in recent experiments. Consequences of
pseudodoping for many-body instabilities are discussed.
