In a clinical trial for Regrowz UK by Princeton Consumer Research in 2015, three study groups were given instructions to apply either the Regrowz Restoration Serum and a natural remedy (Group 1), the Regrowz Scalp Stimulator and Restoration Serum (Group 2), or a placebo (Group 3) over a period of three months. None of the participants knew which group they were in. Subjects underwent both objective and subjective assessments on day one of the trial and then at the end of months one, two and three. Assessments were carried out by a qualified examiner according to the Severity Alopecia Tool (SALT) to determine the amount of hair coverage and loss. They also underwent photography of the treatment area and completed self-perception questionnaires to capture their own opinions about their hair growth.