Latest results in rare decays at LHCb

Recent results from the LHCb experiment on decays governed by $b \rightarrow s\mu^+\mu^-$ or $b\rightarrow s\gamma$ transitions are reviewed. The updated isospin asymmetry in $B \rightarrow K^{(*)} \mu^+\mu^-$ decay are in good agreement with the Standard Model. Results of the angular analysis of $B \rightarrow K\mu^+ \mu^-$ decay help to exclude large cancellation between left- and right-handed couplings in the $B^0_s \rightarrow \mu^+\mu^-$ decay. Finally using the decay $B^+ \rightarrow K^+\pi^-\pi^+\gamma$, nonzero photon polarization is observed for the first time in $b\rightarrow s\gamma$ transitions.