Hair loss is typically related to genetic and/or hormonal factors. In these cases, to grow new hair and prevent future hair loss, it's best to initiate treatment as early as possible. Once results are achieved, it's important to continue treatment long-term for maintenance.

That said, when hair loss is related to stressful events, a crash diet, or pregnancy, hair loss treatment can be used for shorter periods: usually, about 9-12 months after excessive hair shedding lessens.