SMP Follicle Size – Smaller Is Not Better

Much is made of follicle size among some SMP clinics. We take a close look at the science behind getting it right, and blow away some myths in the meantime.


From the earliest attempts at SMP getting the size of the follicle just right was clearly going to be a vital element. Bespoke needles were developed that delivered a precise amount of pigment at exactly the correct depth, along with the experience of the practitioner this underpinned success. It still does.

Let us start by spending a moment looking at some of the claims that motivated this article in the first place. They are around the use of smaller needles, with which smaller dots are produced. It is wrong to claim that this improves the outcome of the SMP, for some very sound scientific reasons.

How Big Is A Real Hair Follicle?

measuring tape

It is an important question to start with isn’t it? What exactly is it your practitioner will be trying to .recreate?

There is a mathematically significant difference between the diameters of hair follicles among different ethnicities. So that a Caucasian would be expected to have a diameter of just under 80 micrometers (Um), an Asian would be between a little under 70 Um and an African between 110 and 120Um. We describe it as a mathematically significant difference because the human eye cannot really distinguish differences between dots of this size in any meaningful way.

How Does SMP Mimic These Dots

carbon copy

Typically, a recreated follicle will appear anything up to 250Um in diameter immediately post treatment. There will be an initial period of settling that will see small scabs appear, when they fall away the remaining dots will be much smaller. Through diffusion and the actions of your immune system they will shrink down to between 100 to 150UM. While this does mean that they are slightly larger than the real thing the difference is imperceptible to the eye, even from just a few inches away.

Why Not Make Them Smaller?

magnifying glass

Producing smaller dots was always an option, it still is. There are sound scientific reasons why it is not recommended. Using carbon fibre filaments it is possible to produce dots as small as 30Um. There are a couple of principal issues with doing that – To start with, the appearance of the dot through the skin would just be too small to be noticed from anything more than two or three feet away, though it would look great close up. For while at least.

The spherical boundaries of those tiny dots will be eaten away by the immune system, the visual impact of that on a smaller dot is much greater than with slightly larger ones. The size of the dot also correlates to it’s half-life, the time before you will need to go back for a touch up… though that would be soon in any case as the immune system eating away at the edges, will quickly reduce the overall appearance of the SMP to that of a thin coat of grey emulsion.

Perfectly Proportioned and Positioned Pigment

It is years of experience combined with a deep understanding of the biological processes involved that has arrived at the perfect dot size. A dot that shrinks after treatment to settle at around 110Um is ideal. It is large enough to defend itself from the ravages of the body’s defences and to be seen as perfect by an observer, not least because the density produced at that dot size has also been proven to work.

SMP Debate


So be wary of claims that revolve around proprietary needles that promise to deliver smaller dots. This does not equate to a better SMP, quite the reverse in fact.

Add it to the list of questions you are asking of your clinic… or drop us a line for any SMP related advice you need. We are always happy to help and can be reached at

Laurie Downing