Mike Murphy's Blog

This is an interesting question. Virtually everyone’s initial response would be a resounding “NO”. “Why should we? We would be removing the target we are trying to destroy!!”

Well, yes, of course. That’s obvious.

Except, it isn’t…

A telogen hair, about to transition into anagen 1.

To answer this question properly, we need to look closely at the growth cycle of hair. In particular, the anagen phase of this cycle.

Research indicates that there are six stages within the anagen phase. I’ve listed them in the table below.

Phase	Progress
A1	Stem cells undergo a rapid period of mitotic activity, resulting in activation of the hair germ. New melanosomes begin to grow in the bulb and the bulge stem cells begin to proliferate rapidly. This stage lasts for only a few hours.
A2	A short period when the stem cells start to grow around the dermal papilla (DP). The bulb and DP begin to descend towards the sub-cutis (fat layer) at a rate of around 0.25 mm per day.
A3	Most of the structural development of the follicle occurs in this stage. The follicle will eventually reach its full length. By the end of this stage, the bulb and matrix are fully formed – these are mainly responsible for the growth of the hair shaft. Blood vessels begin to connect to the bulb. The hair shaft begins to attain some colour due to new melanosomes. This stage can last between 6 and 12 days, depending on the thickness of the local dermis.
A4	In the upper bulb region, a cone begins to form. This will become the cortex and medulla of the hair shaft containing melanosomes. At this point, a club hair (which forms during the catagen phase) may remain in the telogen follicle, occupying the pilary canal where the newly formed hair shaft is growing. The club hair may be shed at this time (exogen). Melanin pigmentation of the hair shaft begins in earnest.
A5	The tip of the hair shaft now breaks through the top of the internal sheath, which is about level with the epidermis. The new hair now becomes visible for the first time. The follicle structure is fully formed by the end of stage 5.
A6	The hair shaft continues to grow through the epidermis for the duration of the anagen phase, at a rate of around 0.27 to 0.45 mm/day, depending on the body site and ethnicity. The final length of the hair is determined by the duration of this anagen stage.

Table 1 – the six anagen stages of follicle development, Data from Ross et.al., Chase, Bouabbache et.al., Uno, Muller-Rover et.al., Alonso and Fuchs, Baker and Murray, Bernard, Buffoli et.al., Greco et.al.

We can see that the newly growing hair shaft does not begin to pick up any colour until late in the third anagen stage (A3). It attains most of its colour (new melanosomes) in stages 4 and 5 (see table 2).

But, and this is the important bit(!!), the new hair shaft does not become visible until stage 5. By this time, the bulb is firmly anchored in the sub-cutis, far from the skin surface.

Stage	New hair shaft	Follicle development
A1	Has not started to develop yet.	Whole follicle very near to the skin surface.
A2	As above.	The follicle is beginning to develop but is still close to the surface.
A3	The new hair shaft begins to grow. It has no colour in it until the latter part of this stage.	The lower part of the follicle begins to grow towards the fatty layer.
A4	The hair contains more melanin now and is growing towards the skin surface. It is still not visible.	The follicle is now fully developed and anchored in the sub-cutis.
A5	The hair breaks through the skin surface for the first time.	Fully developed
A6	Most of the growth of the hair shaft occurs in this stage, determining its final length.	Fully developed

Table 2 – the various processes which occur during the anagen growth phase.

So, what does this mean?

The targets we are trying to kill are the stem cells – they are located in the bulge, the bulb and in the outer root sheaths. Research indicates that we need to kill a significant portion of these cells to ensure complete follicle death.

But, these stem cells do not have a chromophore which we can target will light energy. So, we use melanin instead, which absorbs all the wavelengths in the visible spectrum plus some light in the near infrared part of the spectrum.

By heating the melanosomes sufficiently, we can ‘cook’ the real target – the stem cells.

Clearly, the ‘best’ time to do this is when most of those cells are close to the skin surface. This is from A1 to early A3. But, during A3, the lower part of the follicle descends towards the fatty layer, taking the target stem cells, and melanosomes, in the bulb with it!

We know that fluence drops exponentially with depth – deeper targets are much more difficult to treat than superficial ones.

So, as the bulb descends, it becomes more and more difficult to treat effectively. Once the bulb reaches the sub-cutis, it is too deep to reach with a sufficient amount of light energy. Those targets are out of reach for many devices (especially with the ‘recommended’ protocols)!

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What are visible hairs?

Let’s consider the hairs we can see.

Firstly, they must be in either anagen, catagen or telogen. We know that follicles in catagen and telogen don’t have enough melanin in the bulb region (the melanosomes migrate away from the bulb during catagen). This means that those hairs are not good targets – there is insufficient melanin in the bulb to effectively destroy them.

Secondly, the anagen hairs we can see MUST ALL be in late anagen – A5 to A6. That’s because the hair shaft does not become visible until A5. This tells us that all the anagen hairs that we can see, are already located in the sub-cutis. As we have seen above, these are too deep for the light energy to do anything significant. In fact, treating these hairs will merely ‘stun’ the follicle, but not kill it. This will lead to finer, lighter-coloured hair growing back in the next anagen growth phase.

So here is the rather curious summary:

catagen and telogen hairs cannot be effectively treated due to lack of melanin;

and, visible anagen hairs are too deep to treat effectively.

This means that ALL visible hairs cannot be treated using light energy. The hairs we are targeting are not visible to the naked eye. The follicles, and new hairs shafts, are growing, but we simply cannot see anything!

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Why waxing or plucking?

Why should we consider waxing or plucking (or any method which physically removes the hairs)?

Well, there are a number of reasons why removing the hairs is potentially beneficial:

1. Any hair which is visible will absorb some light energy during treatments. These hairs will become hot and, therefore, induce some thermal pain. This pain is completely unnecessary, since cooking these hairs has no real benefit!

• Removing all the hairs prior to treatment will significantly reduce the amount of plume (smoke) in the air. Studies have shown that plume is potentially dangerous. It can contain toxic and carcinogenic substances – we don’t really want to be breathing that stuff all day!!

• If fewer hairs are in the treatment site, then there will inevitably be less trauma and a lower incidence of post-treatment problems. This means a faster recovery time, a lower probability of complications and fewer complaints!

• Finally, if we remove all the visible hairs before laser/IPL treatment, then there will be a much longer period after each treatment sessions when no hairs are visible. New anagen hairs will not appears for quite some time because the treatment should have knocked out all the early growth. Any later growth will be stunned – this forces the follicles back into a ‘catagen-like’ stage (as has been observed in many clinical and histological studies). As a consequence, your patients/clients will be hair-free for longer and much happier!

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Summary

It does seem quite bizarre to be considering waxing or plucking before laser/IPL treatments. But the analysis of the anagen growth stages reveals that it may well be the best option. All visible hairs are ‘redundant’ – they are NOT the real targets.

The actual targets have not yet revealed themselves. They are invisible to us.

But there are clear benefits from removing all the hairs prior to treatment – less pain, less trauma, less plume and a better outcome for patients/clients.

One of our friends has tried this – waxing before lasering, on herself. She told us that there is no smell of plume at all after the treatment! Just as we predicted.

If you have tried this, please let us know your findings.

Hey ho. Hope this helps.

Mike.

PS We spoke about this in our podcast. Please give it a listen and sign up.

Apple Podcasts – https://podcasts.apple.com/…/lasers-in-skin/id1790635555

Spotify – https://open.spotify.com/show/6qWY0GOunSjOvYzNmEPeUX

Audible – https://www.audible.co.uk/…/Welcome-to-the…/B0DWZVJQ91

PPS Clinical references are available on request.

PPPS I am currently writing this up for publication in a journal…