"5% topical minoxidil applied twice daily was recently proven more efficacious than the previously recommended 2% minoxidil; however, there is a higher incidence of side effects with the stronger preparation such as scalp pruritus, local irritation, and unwanted hypertrichosis (Callender et al., 2004). " --Medscape
Telogen effluvium due to stress or medications
​Treat underlying disorder (such as anemia or hypothyroidism)