VHE SED of Mrk 421 derived from the MAGIC-I observations performed on 2008 March 30, when the flux rose to 3.6 Crab Units. Data points before (black open triangles) and after (red filled circles) applying a correction for EBL absorption following Franceschini et al. (2008) are shown. The observed position of the IC peak is evaluated at  ~500 GeV from the fit with a curved power law, and above 1 TeV after deabsorption. This VHE spectrum was the hardest among the ones studied here, as illustrated in Fig. 4.