Medical Microneedling: Why Depth Matters

Medical Microneedling: Why Depth Matters

If you’ve researched microneedling, you may have heard two very different messages:

“The deeper the treatment, the better the results.”

Or, on the other end:

“You can achieve the same results with shallow microneedling.”

The truth is more nuanced.

When it comes to medical microneedling, deeper is not always better—but shallower is not always enough either.

The appropriate treatment depth depends on your skin, the area being treated, tissue thickness, and most importantly, what we are trying to accomplish.

Not All Microneedling Has the Same Goal

Microneedling works by creating controlled micro-injuries within the skin. These micro-injuries initiate the body’s natural wound-healing response and stimulate processes involved in collagen and elastin production and tissue remodeling.[1]

However, not every microneedling treatment has the same goal.

A treatment intended to improve overall skin quality is different from one specifically targeting established acne scarring or stretch marks.

More superficial treatments may be appropriate when the goal is improvement in concerns such as:

• Overall skin texture
• Fine lines
• Enlarged pores
• Dullness
• Overall skin quality and radiance

These treatments can provide beautiful visible improvement without unnecessarily treating the skin at greater depths.

Acne Scars Are Different

Atrophic acne scars are more than an uneven skin surface. They involve structural changes within the dermis, including collagen loss and remodeling.[1]

When treating acne scarring, the goal is therefore different from general skin rejuvenation. We are trying to encourage a controlled healing response and remodeling within the tissue involved in the scar.

Research supports microneedling as an effective treatment option for atrophic acne scarring. A systematic review of randomized controlled trials found microneedling to be an effective and well-tolerated treatment for atrophic acne scars, both alone and when combined with other treatments.[1]

More importantly, emerging research suggests that treatment depth can influence results when specifically treating atrophic acne scars.

A 2024 split-face comparative study treated 14 patients with atrophic post-acne scars using a Dermapen. Each patient received six treatments, with one side of the face treated using a 1.5 mm needle length and the other using 2.5 mm.

Both sides demonstrated improvement in collagen bundles and elastic fibers.

However, the side treated at 2.5 mm demonstrated significantly greater clinical improvement in acne scarring than the side treated at 1.5 mm.[2]

This is an important distinction.

It does not mean that everyone with acne scars should be treated at 2.5 mm, nor does it mean that every area of the face should be treated deeply.

It does demonstrate that when we are treating established dermal scarring, depth is a meaningful treatment variable.

What About Stretch Marks?

Stretch marks, medically known as striae distensae, also involve structural changes within the dermis.

Microneedling has been studied as a treatment for stretch marks because of its ability to initiate a wound-healing and remodeling response within the skin.

A 2024 systematic review and meta-analysis evaluated 11 eligible studies involving microneedling treatments for striae distensae and found initial evidence supporting the effectiveness and safety of microneedling for stretch marks.[3]

As with acne scars, treatment should be selected based on the tissue and concern being addressed rather than assuming that one standardized depth is appropriate for every treatment.

So Why Can Shallower Microneedling Still Look So Good?

Because superficial improvement is still real improvement.

After microneedling, skin may appear smoother, brighter, plumper, and more refined. Improvements in overall skin quality can also make imperfections appear less noticeable.

And importantly, shallower microneedling does not mean that collagen stimulation isn't occurring.

In the 2024 depth-comparison study, researchers observed improvement in collagen bundles and elastic fibers on both the 1.5 mm and 2.5 mm sides.[2]

The difference was that the deeper treatment produced significantly greater clinical improvement in the atrophic acne scars in that particular study.

This helps illustrate an important concept:

Improving the overall appearance of the skin and specifically targeting established dermal scar tissue are not necessarily the same treatment goal.

Deeper Isn't Always Better

If deeper treatment can be beneficial for certain scars, why not simply treat the entire face deeply?

Because unnecessary depth does not automatically equal a better treatment.

Different areas of the face have different anatomy and tissue thickness. Treatment parameters should take the specific area, individual skin characteristics, scar type, treatment goal, previous response, and other patient-specific factors into consideration.

A delicate area of the face should not automatically be treated the same way as a thicker area containing established atrophic scarring.

The goal of medical microneedling is not to use the deepest setting possible.

It is to create an appropriate controlled injury for the tissue and condition being treated while avoiding unnecessary trauma.

Medical vs. Cosmetic Microneedling: What's the Difference?

Not all microneedling is the same, and one of the most important distinctions is the difference between cosmetic microneedling and medical microneedling.

In Minnesota, advanced practice esthetic services including skin needling are limited to cosmetic treatment of the epidermal layer of the skin.[4] Because cosmetic microneedling remains superficial, it can be beneficial when the goal is improving the overall appearance of the skin, including texture, radiance, and general skin rejuvenation.

Medical microneedling (done by medical providers) penetrates beyond the epidermis and into the dermis. This is where the distinction becomes especially important when discussing concerns such as atrophic acne scars and stretch marks, which involve structural changes within the dermal tissue.

Reaching the dermis does not mean that every area should be treated at the same depth or that the deepest possible treatment will produce the best result. Medical microneedling should still be individualized. Treatment depth can be adjusted throughout the procedure based on anatomy, tissue thickness, treatment area, scar characteristics, and the individual's skin response.

For example, thinner and more delicate areas of the face require conservative treatment, while thicker areas or areas of established dermal scarring may require different parameters.

This is one of the key advantages of medical microneedling when the treatment goal extends beyond superficial skin rejuvenation: the treatment can be customized to appropriately target the tissue involved in the concern.

Cosmetic microneedling has an important role in superficial skin rejuvenation. However, when the goal is to address concerns involving the dermis, such as established atrophic acne scars or stretch marks. Medical microneedling allows treatment beyond the epidermal level.

Ultimately, it isn't about treating as deeply as possible.

It's about treating the appropriate layer of skin, at an appropriate depth, for the concern being addressed.

There Is No Universal “Best” Depth

Microneedling research does not establish one universal treatment depth that is ideal for every patient, every area, or every condition.

Published studies vary in the devices used, treatment techniques, depths, number of sessions, treatment intervals, and types of scars being treated.[1]

Research also continues to evolve.

What the available evidence does demonstrate is that microneedling can stimulate collagen remodeling and improve atrophic acne scarring and that treatment depth can influence outcomes when dermal scarring is the treatment target.[1,2]

That is why medical microneedling should not be approached as a one-size-fits-all treatment.

At MinnGlow Aesthetics, medical microneedling treatments are customized according to the individual, treatment area, skin characteristics, and specific concern being addressed.

Someone seeking general skin rejuvenation does not necessarily require the same treatment parameters as someone seeking improvement in established acne scarring.

A forehead does not need to be treated like a cheek.

And facial rejuvenation does not require the same approach as treating a stretch mark on the body.

Deeper isn't always better. Shallower isn't always better.

The goal is the right depth, in the right area, for the right reason.

References

1. Sitohang IBS, Sirait SAP, Suryanegara J. Microneedling in the treatment of atrophic scars: A systematic review of randomised controlled trials. International Wound Journal. 2021;18(5):577–585. doi:10.1111/iwj.13559.

2. El-Domyati M, Moftah NH, Ahmed AM, Ibrahim MR. Evaluation of microneedling depth of penetration in management of atrophic acne scars: a split-face comparative study. International Journal of Dermatology. 2024;63(5):632–638. doi:10.1111/ijd.17006.

3. Sun X, Jia X, Huang L. Microneedling Therapy for Striae Distensae: Systematic Review and Meta-Analysis. Aesthetic Plastic Surgery. 2024;48(15):2915–2926. doi:10.1007/s00266-024-03954-x.

4. Minnesota Administrative Rules. Rule 2105.0105, Subpart 5: Advanced Practice Esthetic Services. Minnesota Office of the Revisor of Statutes. https://www.revisor.mn.gov/rules/2105.0105/

This information is provided for general educational purposes and does not replace an individualized consultation. Appropriate microneedling treatment parameters vary depending on the individual, treatment area, and condition being treated