It is common to hear online that a major contributor to men’s hair loss or Androgenic Alopecia (AGA) is due to a lack of blood flow to the scalp. It is common for people online to claim treatments like scalp massages, topical caffeine, microneedling, red light laser caps and more will help stop hair loss by increasing blood flow to your scalp but this is simply not true. The main reason provided for this is because Minoxidil, an FDA approved treatment for androgenic alopecia was believed to work by increasing blood flow to the scalp. However this is no longer the prevailing theory, and it is important to consider that Minoxidil doesn’t actually stop Androgenic Alopecia it just regrows hairs. For those who don’t know, Androgenic Alopecia is caused primarily by a hormone called DHT (Dihydrotestosterone) binding to the androgen receptor of scalp hair follicles leading to changes in the hair growth cycle (miniaturisation) and its eventual death. The regrowth of hair will improve cosmetic appearance but it will not stop the process from continuing to occur, and often does not occur fast enough to cover up balding areas. This is why Minoxidil isn’t not considered an effective Monotherapy treatment. 

Interestingly, the theory about blood flow being the culprit of Male Pattern Baldness was disproved over a CENTURY ago in a study titled ‘INHERITANCE OF BALDNESS’ by Dorothy Osborn.

Within this study, Osborn was able to first identify what we know to be true today, that Androgenic Alopecia is a genetic condition thus members of a family with this genetic predisposition to AGA suffer from it. You’ve probably seen this in your day to day life, by observing sons of a bald dad show signs of balding, and that adult brothers of similar ages usually show the same signs and patterns of balding. 

The prevailing theory prior to this study is that hats could be culprit of hair loss, because they restrict blood flow. However Osborn recognised that in families with no inherited baldness, whether or not the men would wear hats did not cause changes in their amount of hair. She also noted that place hats worn simply did not match the pattern of baldness.

Despite this theory being disproved over a century ago, it is commonplace for people to claim blood flow to be the cause of AGA. You’ve probably also noticed that the same people that claim this are often trying to sell products that improve blood flow. Clearly they have an incentive in making this claim and I believe this is likely why the theory has widespread appeal.

Take a look at men and women, almost all men have some level of hair loss whereas it is quite rare to see clear signs of balding amongst women. Think about why this is. Is it because women for whatever reason have better blood flow to their scalp. No, but one way we do differ from women is having different levels of sex hormones in our body. The unfortunate reality is it doesn’t matter how many scalp massages you do, your sex hormones are the cause of the problem, and blood flow won’t change that.

So then how does Minoxidil cause hair regrowth?

Well the exact reason Minoxidil causes hair regrowth is still debated amongst researchers and experts in this field, but technically it may be due to its vasodilating properties. The only issue is there are many vasodilators however not all of them lead to hair growth, which suggests it may be due to other properties of minoxidil. 

Minoxidil may stimulate the production of hair growth factors, such as epidermal growth factor (EGF) and certain prostaglandins, which play a role in the hair growth cycle.

You have to consider that there are many many vasodilators on the market, yet Minoxidil is the only one that i’m aware of with Hirsutism as a listed side effect. What this indicates is that Minoxidil has unique properties, not related to its vasodilatory effects, that promote the growth of hair.

Even if minoxidil-induced hair growth is purely attributed to scalp blood flow, it is important to remind yourself that using any pro-blood flow compounds on your scalp will not prevent further hair loss caused by the male sex hormone (androgen) DHT.

Ultimately, the misconception that blood flow is the primary cause of Androgenic Alopecia (AGA) has been debunked for over a century. The truth is, AGA is a genetic condition driven by the hormone DHT, which causes the miniaturisation and eventual loss of hair follicles. You’d be better off focusing on stopping further progression of AGA, rather than trying to improve scalp blood flow using unproven methods. Finasteride paired with Minoxidil remains the most effective treatment of Androgenic Alopecia amongst those in the know.

Refrences:

INHERITANCE OF BALDNESS: Various Patterns Due to Heredity and Sometimes Present at Birth—A Sex-limited Character—Dominant in Man—Women Not Bald Unless They Inherit Tendency from Both Parents Get access Arrow

DOROTHY OSBORN
Journal of Heredity, Volume 7, Issue 8, August 1916, Pages 347–355, https://doi.org/10.1093/oxfordjournals.jhered.a110746