**This post is mostly for nerds like us, who want to understand the biology behind hair growth, hair loss and hair follicle in general. However as a wholesome hair growing blog, we can’t remain ignorant as to whether hair follicle dies and even IF it does appear dead, what happens next and IF it can be revived.**
If you are not growing visible hair, it does not mean that the hair follicle is dead. In order to destroy a hair follicle, one needs to damage the bulb or the root of the hair follicle where the blood supplies it with oxygen – which takes significantly longer time than people tend to believe. In addition, the stem cells responsible for hair follicle regeneration need to be absent too.
This should give a message of hope: unless you have had a deep wound or follicles have died during long-term balding process – death of a hair follicle is a long process. A follicle is a complex organ which, before dying from “natural causes” – such as hair thinning to androgenic balding, goes through longer cycles and stages: vellus > terminal hair > vellus. This naturally takes years if not decades even if you started seeing the early balding signs, which might provide the extra time to save it, too.
Understanding hair follicle lifecycle
In animals and evolutionarily speaking, the hair growth cycle is needed to renew the protective covering of body hair, while also enabling the seasonal change in coat quality and colour. The length of the phases of the cycle determines the length of the hair and its replacement rate (think of hair moulting/shedding).
In humans, such cycle determines the characteristics of hair across different body areas and also helps to explain what happens in hair loss. The cyclical nature of hair growth has a distinct purpose, however, biologists and technologists are very keen to understand the transitions between the phases of the cycle in order to manipulate hair growth. Much of this area is still unknown however much advancement has been made.
Instead of diving to the stages of anagen (growth), catagen (detachment) and telogen (falling out) – stages of hair growth, we’re looking at the larger cycles that span the entire lifetime of a hair follicle, rather than hair itself. These stages are (1) lanugo (2) vellus and (3) terminal.
1. Lanugo hair
When we are born, some of us retain lanugo hair – a downy-like hair usually found on the body of a fetus or newborn baby. It is the first hair to be produced by the fetal hair follicles, and it usually appears on the fetus at about 5 months of gestation. Lanugo is very fine, soft, and usually unpigmented. It is normally shed before birth, around seven or eight months of gestation, but is sometimes present at birth. It disappears on its own within a few weeks.
2. Vellus hair
Lanugo is replaced by hair covering the same surfaces, which is called vellus hair. This hair is thinner and more difficult to see. This is commonly the “peach fuzz” or just hair on the rest of human body, other than head, eyelashes and eyebrows during childhood.
3. Terminal hair
Some vellus hair changes as we transition into adulthood is called “terminal” hair which forms in specific areas and is hormone-dependent. Such conversion is commonly present in armpit, pubic, chest areas in both genders which react to hormonal changes in human body – whether due to puberty or menopause – or hormonal medication, such as birth control pill or thyroid medication. Terminal hair has a medulla – a central “spine” of the hair, which is typically non-existent in finer, vellus hair. The medulla is a portion of the hair’s core that strengthens it, allowing it to grow longer.
Hair follicle minituarisation before its death
During hair thinning or balding process that could happen due to a variety of reasons – terminal hair progresses back into vellus hair during hair follicle miniaturisation stage, before completely dying.
However for the hair follicle to die completely it takes a long time and some research around stem cells in the hair growing areas point to the fact that even after hair follicle does effectively die (i.e. it does not produce any type of hair, including vellus) – some stem cells can create new hair follicles.
For now, it is important to remember, that just because there is no visible hair – it does not mean that hair follicle is dead. Oftentimes even visibly completely bald scalp has some peach fuzz, which points to the fact that the follicles aren’t dead, they are just in a different stage however, going through hair follicle minitiarrisation stage as a vellus hair.
What makes a hair follicle dead?
Dead hair follicle is the one that no longer can grow hair. So it is important at the miniaturisation stage to know that once hair follicle is entering leads to reduction in blood supply. Although it is often not the lack of blood flow that leads to baldness, especially in males, but rather it is the result of it.
The lack of appropriate blood circulation worsens and speeds up the hair loss, since the root no longer receives oxygen and other nutrients normally delivered by blood vessels connected to hair via a nipple-like extension, known as derma papilla. Therefore this lack of nutrition leads to a catch-22 process of hair miniaturisation and ultimately its death.
Dead hair follicle re-birth
Stem cells in follicle formation
Aside from the differentiation between vellus hair and terminal hair, there is a number of stem cells present in scalp. Those stem cells need to transition to “progenitor” stage before leading to hair growth. You can think about progenitor cells not entirely devoid of purpose, like stem cells – but rather those which already leaning towards a target cell. Interestingly, in balding men, scientists observed the same amount of stem cells in the balding areas as in the non-balding areas, though in the non-balding areas there was a greater number of activated progenitor cells.
Dead hair follicles in patterns of baldness
In androgenic alopecia (AGA) – commonly the reason behind male pattern baldness, is not only limited to men. AGA highlights specific areas that exhibit thinning of the hair first: specifically frontal and vertex (crown) areas. These are the areas with most androgen-receptors – therefore those that react the most to dehydrotestosterone (DHT) attacking them, ultimately leading to hair follicle miniaturisation and visible baldness. As such, many treatments for baldness attempt to convert vellus hair back to terminal hair by preventing DHT from attacking the hair root. Because it is much easier to reverse the hair thinning, while hair follicle produces at least some type of hair, hair loss treatments are more efficient in delivering visible results faster, before the hair enters the vellus stage.
While topic is common amongst balding males, there are plenty of instances of androgenic female pattern hair loss, especially linked to menopause or polycystic ovary syndrome, due to changes in hormonal balance and increase in production of androgens. The process of hair follicle going back to vellus hair before completely dying applies to all genders.
Stimulate hair follicles for hair re-growth
Firstly, let us be very clear – acting early is key. The good news is that if you have ANY hair – even if it just looks like fluff – it means that your hair follicles are alive and kicking. They might need support – through the right nutrients, hormone regulation and stimulated blood flow – but there is absolutely something you can do about it.
While balanced, nutrient-rich diet, right supplements and exercise are paramount in achieving hair growth – stimulation of blood flow in scalp is key. It isn’t as easy as popping pills and spraying minoxidil on your hair roots, blood flow stimulation of scalp is one of the most promising sustainable solutions for improved hair growth, re-growth and reduction of hair loss. Some techniques include, scalp massages, derma-rolling or micro needling. Scalp treatments like The Hair Fuel stimulates the blood flow to the hair follicles, and delivers its own nutrients directly to your scalp.
Hair thinning and hair loss treatments are the most efficient in early stages of hair loss – when you just start noticing hair thinning and some smaller, often transparent vellus hair taking its place. It is much harder to revive a dead hair follicle and stimulate formation of progenitor cells – than the one which is still operating.
Read our summary on the latest research in Saw Palmetto supplement as a way to tackle androgenic alopecia here >>
Bald scalp in men with androgenetic alopecia retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells (1)
The biology of hair diversity, (2)
Multivariate analysis of prognostic factors in patients with rapidly progressive alopecia areata (3)
Subcutaneous blood flow in early male pattern baldness (4)