EMDR therapy is generally considered to be safe, and not harmful or dangerous. If you experience any EMDR side effects at all, they may include light-headedness or heightened emotions/physical sensations after the session. If you experience this, it should subside over time as the memories become less intense. EMDR may be contraindicated in those with certain health conditions, and this is something I discuss with clients to ensure that it is a good fit before we begin.