microneedling for hair regrowth
Microneedling is great for skin quality and for hair regrowth. For skin it will help improve collagen, elastin, skin quality, pore size, and more. For hair microneedling has been shown to stimulate hair growth, statistically significantly, on its own- without products, just the needling.
The theory on why microneedling works in a medical setting with high grade sterile needles placed to a correct depth (Yes, this is me pleading for you to not try this at home), is that it stimulates the wound healing cascade, which causes the release of growth factors, hair follicle stem cells, and new vascularization of the scalp.
Scalp anatomy
How deep should you go? If you look at the scalp, you will see a wide range of “thickness” of the scalp. In my quest to understand this as much as I can, I found an original paper about scalp anatomy. For this I went totally old school, and found a paper published in 1972, “The Thickness of Human Scalp: Normal and Bald” from the Journal of Investigative Dermatology. They studied the thickness of the layers in normal and bald scalps. This was done on male and female cadavers and on living male subjects at different stations of hair loss.
- There are 4 layers to the scalp: Epidermis, Dermis, Subcutaneous fat, and Galea Capitis
- Each scalp layer changes with aging.
- EPIDERMIS. In women, the thickness of the epidermis increases until age 40, for men until age 50.
- DERMIS is thicker in women than in men. At age 35 it starts to wane for women, for men it wanes at age 55.
- The most noticeable changes are in the layers that contain hair.
- For bald subjects, in early male pattern hair loss (alopecia) there are not changes in scalp thickness, but in advanced baldness, all layers except the galea have definite thinning.
A plastic surgical textbook estimated the layer thicknesses: Epidermis 1.5mm, Dermis 2-4mm, Subcutaneous layer 4-7 mm (though some have 20mm thickness), and Galea (thin). It is thinner near the crown of the head, and thicker near the back of the head.
The hair follicle and hair bulb, where growth occurs, is in the dermis. This is where the blood supply, nerves, and oil glands are. The base of the hair follicle may extend into the subcutaneous layer below the dermis, where blood supply is necessary to nourish the growing hair.
Journal article: ideal depth for microneedling for hair regrowth
In this study they wanted to look at how deep should you microneedle? They looked at 60 patients, ages 18-45 who were showing signs of androgenetic alopecia (AGA). They had 3 groups. “Microneedling in androgenetic alopecia; comparing two different depths of microneedles”, Cosmetic Dermatology
Study:
- Sixty patients, ages 18-45, with moderate and severe AGA, done biweekly for 12 weeks
- Three study groups. A control group plus:
- treatment with minoxidil 5% lotion and biweekly microneedling with a depth of 1.2 mm
- treatment with minoxidil 5% lotion and biweekly microneedling with a depth of 0.6 mm
- Data collected: change of hair count, hair thickness from baseline, and assessment of hair growth by patient and investigator
- Findings? All three groups had significant increase in hair count and thickness
- The 0.6mm group had significantly greater rise in hair count than the 1.2mm group.
What we do at Lauren Greenberg MD
This is still a rapidly evolving landscape. I put these two studies in here to show that microneedling is CLEARLY a good thing to combat hair thinning and hair loss. Every study supports it, and shows statistically larger improvements when done in combination therapy. That science is clear.
What is not clear yet are the other parameters. How deep, how often, for how long. This study at 0.6mm vs 1.2mm was done biweekly. There are other studies which show that may be “too frequent” if doing a deeper depth as it does not give the scalp time to recover. There are some studies which indicate if you go deeper that it would allow fewer treatments. When looking at the anatomy, it seems the dermis is where the action is. The lower depth needles would not be reaching that. So is the key to go slightly deeper, less frequently?
The scalp study above also indicates that scalp thickness varies a lot, by gender, age, and site on the scalp. We feel that you want to aim for the dermis/subcutaneous junction. That is where the hair follicle and its blood supply live. Just as with our microneedling treatments to the face, we make an individual diagram of each patient’s anatomy. During the first treatment we use the feedback we get and adjust the depth to aim for that junction. So we think the answer is going to be much more individual- Man/woman, Age, Where on Scalp.
Medical references
“The Thickness of Human Scalp: Normal and Bald” from the Journal of Investigative Dermatology.
The information provided on this website is for general informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider for any questions regarding your health or medical condition.
