Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Subjects are randomly allocated to ultra-early TXA therapy or standard treatment. Complications are minor and the expected benefit is large compared with separate studies done with antifibrinolytic medications. In these studies, the safety of the use of these medications in this study population is confirmed. In this patient group there are adequate, disoriented and comatose patients on admission, so a part of the studied patients are incapacitated when undergoing the study. To extrapolate the conclusions of this study to clinical protocols it is necessary to include patients with a SAH in all different severity grades. Weighing carefully the benefits versus the burden and risks, it is assumed that patients will benefit from ultra-early TXA administration with minimal burden during therapy.