Finasteride is a common oral medication used to address male pattern hair loss. When beginning this treatment, an initial period of increased hair shedding is a known and often anticipated side effect. This temporary phase, while sometimes concerning, is part of the treatment process.
Understanding Finasteride Shedding
Finasteride works as a 5-alpha-reductase inhibitor. This medication specifically targets and blocks the type II 5-alpha-reductase enzyme, which is responsible for converting testosterone into dihydrotestosterone (DHT). Elevated DHT levels are a primary contributor to the miniaturization of hair follicles in individuals with male pattern baldness. By reducing DHT levels, finasteride helps to counteract this process.
The human hair undergoes a continuous cycle consisting of several phases: anagen (growth), catagen (transition), telogen (resting), and exogen (shedding). Finasteride can induce an initial shedding phase because it influences this natural cycle. The medication accelerates the transition of weaker, older hairs from the telogen (resting) phase into the exogen (shedding) phase. This synchronized shedding makes way for the growth of new, healthier hairs that are less susceptible to DHT’s effects.
Typical Duration of Finasteride Shedding
The duration of finasteride shedding lasts a few weeks to several months. Most people who experience shedding notice an increase in hair fall within one to three months of starting treatment. This shedding often peaks around the two to three-month mark.
For many, the shedding phase usually resolves within six months of consistent use. While some reports suggest it might last as little as two to four weeks, a more common timeframe for the active shedding to subside is within two to four months. After approximately three to four months, new hair growth should begin to offset any excess shedding. It is important to continue the medication consistently during this period.
Interpreting the Shed and What Comes Next
An initial shedding phase when starting finasteride is a positive indication. This suggests the medication is effectively influencing the hair growth cycle, pushing out older, weaker hairs to encourage new, more robust growth.
Following the shedding phase, individuals can anticipate the regrowth of healthier and often thicker hair. Over time, the hair follicles that were previously miniaturized by DHT begin to produce stronger strands. Improvements in hair density and overall hair shaft diameter can become noticeable as treatment progresses.
If shedding becomes unusually severe, persists beyond six months, or is accompanied by other symptoms like scalp pain or inflammation, consulting a healthcare professional is advisable to rule out other potential causes.