"Regrowth Rate" is loosely defined as the amount of hair regrowth achieved by any intervention. Oftentimes, this is represented as a total change in hair density – or the ∆hair counts x ∆hair diameters – in a fixed area of the scalp.
Regrowth rates are influenced by treatments, time horizons, demographics, severities of hair loss, and the fixed scalp regions investigators decide to measure in their studies. As such, regrowth rates can vary wildly across studies – even for the same intervention. Consider any regrowth rates discussed here as approximate, and only a tool to gauge the potential magnitude of hair growth you can expect with any intervention.