To explain exactly how minoxidil interacts with the body, it is important to understand what causes hair loss in the first place
Male pattern baldness or androgenic alopecia is characterised by the gradual recession of the hairline beginning at the frontal temporal regions as well as the frontal central area just above the forehead. This genetic condition progresses with balding in the central vertex area that radiates outward and meets with the balding from the front of the scalp. This will continue until the top of the scalp is fully exposed, leaving only the lower portions of the sides and back of the head with hair.
There is also the autoimmune version of alopecia in the form of alopecia areata. This is characterised by the appearance of smooth, round bald spots that sporadically dot the scalp. A progression of this condition will convert it into alopecia totalis or the loss of all the hair upon the scalp. A similar condition is alopecia universalis or the loss of hair over the entire body.
Hair loss is also caused by other factors such as stress, poor diet, an unhealthy lifestyle, excessive alcohol intake, smoking, disease, infection and traumatic life events.
On a cellular level, hair loss begins when the hormone testosterone binds with the enzyme 5-alpha reductase to produce a more powerful hormone called dihydrotestosterone (DHT). This new DHT hormone is attracted to the androgen receptors of the hair follicle and attaches itself to it causing the blockage of essential nutrients coming from the bloodstream. It results in the shrinkage of the hair follicle and causes the hair to shed.
Hair loss can be treated with the use of the drug minoxidil. It is a popular medication to treat androgenetic alopecia in its early stages and has primarily been sold under the brand name Rogaine. This acts by increasing the circumference of the hair resulting in a thicker hair strand. It also lengthens the anagen growth stage of the hair growth cycle causing more hair strands to remain on the scalp. Rogaine is available in 2% or 5% solution that is topically applied daily. The exact physiological relationship it has with hair growth is unknown. What is clear is that it is effective, especially in young men and those that have not experienced hair loss for more than five years. It helps improve hair density in the vertex area in particular though it also enhances other regions of the scalp as well.
Minoxidil was an orally ingested drug used as treatment for extreme high blood pressure. Its effect on the circulatory system helped open the small arteries to allow a smoother, more unrestricted blood flow. The drug however, caused a substantial amount of hair growth especially in women among one of its side effects. This led to the notion that it could also be used to treat hair loss.
Treatment with topical minoxidil is proven to be effective. There are however, side effects that are experienced by a minority of users. Among them is itchiness, dandruff, dizziness, difficulty in breathing and chest pains.
This medication is to be used daily though its full effects may only be seen after a minimum of six months in most cases. It should be applied continually and any cessation of treatment is likely to result in your hair loss ‘catching up’. Note that there is no cure for alopecia. What minoxidil can do is to help suppress its progression, not stop it.
It is true that what exactly causes increased hair circumference and longer hair growth cycle is unknown. A link however, may be appreciated between increased blood flow and thicker hair.