Minoxidil is a hair loss and hair regrowth treatment that’s widely used to treat male pattern hair loss. Like most hair loss treatments, minoxidil begins working immediately but can take several months to produce noticeable results.
Unlike drugs such as finasteride, which prevent hair loss by blocking DHT, minoxidil works by creating an ideal growth environment for your existing hair follicles.
Hair goes through several phases as it grows. At first, it enters into an anagen phase. This is the period in which the hair grows.
After this, it goes into the catagen and telogen phases, in which it shrinks and detaches from the follicle and is replaced by a new hair.
Finally, each hair enters into the exogen phase, during which it falls out from your scalp and is replaced by the new hair.
You can read more about this in our Guide to the Hair Growth Process and Regrowing Hair.
Minoxidil is thought to induce an early anagen phase when it’s applied to your scalp, meaning it can cause hair follicles to go through the rest of the growth process prematurely before starting to grow again.
This is why some people experience hair shedding when they first start using minoxidil. As hair follicles go through the growth process and enter into the anagen phase, old hairs can fall out in large numbers, making it seem as if you’re losing more hair than normal. Minoxidil also prolongs the anagen phase, leading to increased hair length and diameter.
The anagen phase of the hair growth process can last an average of three to five years, during which your hair will grow to its full natural length before starting to shed.
Since minoxidil can start a fresh anagen phase for some of your hair follicles, it usually takes several months before you’ll notice any effects on hair growth.
Most studies indicate that the results from minoxidil usually start to show after six months, with few or no visible results in the first three months of use. There are also studies that don’t show any results at the three-month mark, indicating that minoxidil can take some time to start working.
In one clinical study, 26 percent of men reported moderate to dense hair regrowth after using a two percent minoxidil topical treatment for four months.
This shows that while effective for some people, minoxidil does require patience and willingness to use it consistently.
In conclusion, minoxidil starts working immediately, but won’t produce any noticeable results for the first three to six months. After six months, you should start to see some improvement, with the "final" results usually visible after approximately one year of continuous usage.