Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts.Randomised controlled trial: Subjects are randomly assigned to a test group, which receives the treatment, or a control group, which commonly receives a placebo. In ‘blind’ trials, participants do not know which group they are in; in ‘double blind’ trials, the experimenters do not know either. Blinding trials helps removes bias.People: This is a study based on research using people.Human embryos: This is a study based on research using human embryos.
