Hair growth shampoos and hereditary hair loss

Genetic predisposition
Androgenetic alopecia, as the name suggests, has a clear genetic predisposition and is mainly caused by an excessive reaction to androgens (DHT). This condition is characterized by a polygenetic nature with varying degrees of intensity, which is influenced by both maternal and paternal genes. There is a familial predisposition for androgenetic alopecia, with sons having a 5 to 6 times higher risk if their fathers suffered from baldness.

Mechanism of hair loss
The development of hereditary hair loss depends on the activation of the androgen receptor and is usually observed after puberty. In this process, DHT binds to the androgen receptor of the hair root, which eventually causes calcification of the scalp and miniaturization of the hair follicle, to the point that the hair can no longer penetrate the skin. Castration before puberty and persons with androgen insensitivity syndrome do not show hereditary hair loss [1]. 

In summary
This tells us that hormone metabolism and androgens/androgen receptors play a crucial role in the development of hereditary hair loss[2]. From this we can deduce that tackling the hormone DHT and counteracting its metabolism can be very beneficial in combatting hair loss. 

Genetische aanleg
Androgenetische alopecia, zoals de naam al aangeeft, heeft een duidelijke genetische aanleg en wordt voornamelijk veroorzaakt door een overmatige reactie op androgenen (DHT). Deze aandoening wordt gekenmerkt door een polygenetische aard met variërende mate van intensiteit, die wordt beïnvloed door zowel maternale als paternale genen. Er bestaat een familiale aanleg voor androgenetische alopecia, waarbij zonen een 5 tot 6 keer hoger risico hebben als hun vaders kaalheid vertoonden.

Mechanisme haaruitval
Het ontstaan van erfelijke haaruitval hangt af van de activering van de androgeenreceptor en wordt meestal waargenomen na de puberteit. Hierbij bindt DHT aan de androgeenreceptor van de haarwortel wat op den duur zorgt voor een calcifering van de hoofdhuid en daarbij miniaturisatie van de haarfollikel, tot het punt dat het haartje niet meer door de huid kan penetreren. 
Castratie voor de puberteit en personen met het androgeenongevoeligheidssyndroom vertonen geen erfelijk haaruitval[1].

Samenvattend
Hierdoor weten we dat hormoon metabolisme en androgenen/androgeenreceptoren een cruciale rol spelen bij de ontwikkeling van erfelijk haaruitval[2]. Hieruit kunnen we afleiden dat het tackelen van het hormoon DHT en het tegengaan van het metabolisme ervan veel baat kan hebben bij het tegengaan van haaruitval.

A well-formulated anti-hair loss shampoo tackles the underlying causes related to hereditary hair loss, namely the hormone DHT and the inflammatory process that almost always accompanies it. 

Many anti-hair loss shampoos contain ingredients that stimulate blood flow to the scalp. Good blood circulation ensures that hair follicles receive sufficient nutrients and oxygen, which is essential for healthy hair growth. Just as with inflammation elsewhere in the body, good blood circulation reduces inflammation and thus also the fibrosis of the scalp.

• Caffeine: Stimulates blood circulation and can reduce the effect of DHT. It can prolong the growth phase of the hair, causing hairs to continue growing longer before they fall out [3].
• Niacinamide: Stimulates microcirculation in the hair and has anti-inflammatory properties to protect and nourish the hair root.

This can be done in two ways: either by reducing the amount of DHT in the scalp by hindering the enzyme that converts testosterone into DHT, or by deactivating/occupying the androgenic receptors so that the DHT hormone cannot bind to them and perform its function. Some anti-hair loss shampoos contain ingredients that inhibit the formation of DHT, such as:

• Ketoconazole: An antifungal agent that also acts as a DHT inhibitor and can reduce inflammation in the scalp [4,5,6].
• Piroctone olamine: Like ketoconazole, this is an antifungal agent that also acts as a DHT inhibitor and is anti-inflammatory [6].
• Saw palmetto extract: This herbal supplement can block the conversion of testosterone to DHT, reducing the effects of DHT on hair follicles.

This is quite difficult to quantify, but it is important to do so so that you as a consumer are not disappointed in a hair growth shampoo. No shampoo will revive hair growth roots or completely stop hair loss, but they can contribute to the fight against hair loss.

Below, we explain in a number of articles what the expectations are of the effect of a high-quality hair growth shampoo on hair loss. 

One article examined the effects of 2% ketoconazole vs. 2% minoxidil for 40 patients with female hair loss. Each group was assigned 20 patients and the following parameters were examined:

• Heterogeneity in shaft thickness
• Peripilar sign (BPPS), is an early sign of inflammation in alopecia.
• Yellow dots (overactive sebum production, often goes hand in hand with a poorer hair loss prognosis)

This study concluded that using a 2% ketoconazole 2-4 times a week had similar effects as 2% minoxidil. 

A second study compared 1% versus 2% ketoconazole in their ability to combat the yeast Malassezia on the scalp and the condition seborrheic eczema. Malassezia overgrowth and seborrheic eczema are often observed together with pattern baldness. These conditions lead to excessive sebum production and flaking of the scalp (i.e. dandruff), and can thus accelerate AGA (androgenetic alopecia) through an increase in overall inflammation of the scalp. Furthermore, research suggests that resolving Malassezia overgrowth and seborrheic eczema can promote hair growth. In short, if we are going to use a ketoconazole formulation for hair loss, it will only be beneficial if this formulation also improves these conditions.

The findings of that research team? In reducing the Malassezia load and the flaking of the scalp due to seborrheic eczema, 2% ketoconazole performed better than 1% ketoconazole in both categories. Furthermore, 2% ketoconazole led to fewer relapses of both conditions. That said, 1% also showed a clear improvement in seborrheic eczema and the amount of Malassezia load.

A third study looked at the effects of both 1% ketoconazole and 1% piroctone olamine shampoo on 150 men with hereditary hair loss and dandruff. They had to use this shampoo two to three times a week for six months.

Both treatments showed a reduction in itching and dandruff after 2 to 6 weeks. If we look at the effect of the treatments on various hair growth parameters, we see the following figures (in percentages):

• Hair loss decreases (ketoconazole: -17.3%, Piroctone Olamine: -16.5%)
• The percentage of hairs in the growth phase increases (Ketoconazole 4.9%, Piroctone Olamine: 7.9%).
• The effect on hair diameter is an increase of 5.4% with Ketoconazole and 7.7% with Piroctone Olamine.

The study thus shows that Piroctone Olamine scores better than ketoconazole in a number of areas**:

• Compared to ketoconazole, Piroctone Olamine causes an increase of more than 10% in the number of hairs in the growth phase (anagen phase) in 33% more people.
• With Piroctone Olamine, 88% of people experience thicker hair, despite hereditary hair loss, compared to 78% with ketoconazole.
• If we look at how many people have experienced a significant increase (more than 10%) in hair diameter, this is 28% for ketoconazole and a whopping 34% for Piroctone Olamine (10% larger diameter means that the hair has become 20% heavier).

With this information, we can conclude that shampoos containing 1% piroctone olamine or 1% ketoconazole clearly improve hair growth and reduce dandruff and the fungus responsible for it. If we try to translate this into expected results, we can estimate that 1% ketoconazole or 1% piroctone olamine is less effective than 2% minoxidil when used 2-4 times a week. When a shampoo containing these ingredients is boosted with other hair growth stimulating ingredients, the effect will most likely equal 2% minoxidil or perhaps even be slightly better. 

Because hair loss can be treated best from various angles, it is important to have a good anti-hair loss shampoo in your arsenal and to combine it with other anti-hair loss products such as tablets and lotions for maximum effect.