The Complete Guide to Microneedling
Not yet medically reviewed. This page has not been reviewed by a licensed professional. It summarises published research, cited below, and is not medical advice. Medical disclaimer
Microneedling punctures the skin with rows of fine needles to set off a wound-healing response. The strongest evidence is for atrophic acne scars: a 2022 meta-analysis of 12 randomized trials found it beat the comparison treatments on scar improvement, though the gains in individual trials are modest and many patients see no measurable change. Melasma (when microneedling is paired with a topical such as tranexamic acid), stretch marks and pattern hair loss (with minoxidil) have smaller bodies of randomized evidence. For wrinkles, most studies are small and uncontrolled. Microneedling at home is the least studied version of all: there is one uncontrolled facial study of 11 women using a 0.2 mm device, and no microneedling device is FDA-authorized for home use.
The evidence, condition by condition
| Condition | Best evidence found | What it reported | How strong |
|---|---|---|---|
| Atrophic acne scars | 2022 meta-analysis, 12 RCTs, 414 people (Shen) | Microneedling without radiofrequency beat comparison treatments on objective scar scores (mean difference 0.42); satisfaction mostly no different | Strongest of any use; still small trials |
| Wrinkles and photoaging | 2025 systematic review, 21 studies, 723 people (Foppiani) | 83% of patients satisfied; the authors note there are no standardized measures for aesthetic outcomes | Weak: few controlled trials |
| Melasma | 2022 meta-analysis, 12 studies, 459 people (Bailey) | Microneedling added to a topical improved severity more than the topical alone, a moderate effect at 8 weeks and a large one at 12–16 weeks | Moderate; trials disagree on tranexamic acid |
| Stretch marks | 2024 meta-analysis, 6 RCTs + 5 non-randomized studies (Sun) | Better than non-laser treatments (SMD 1.01); about the same as lasers | Moderate, small studies |
| Pattern hair loss | 2023 meta-analysis, 10 RCTs, 466 people (Abdi) | Microneedling plus minoxidil raised hair counts more than minoxidil alone (SMD 1.76); hair diameter not significantly different | Moderate, combined with a drug |
Atrophic acne scars
Acne scars are where the trial evidence is deepest, and they are the condition FDA clearances name most often. Of the device indications in the FDA records, “to improve the appearance of facial acne scars” in adults is the most common wording.
The 2022 meta-analysis by Shen and colleagues (Taipei Medical University) pooled 12 randomized trials with 414 participants that compared microneedling against other treatments. For objective scar improvement, plain microneedling came out ahead with a mean difference of 0.42 on the trials’ scar scales. Radiofrequency microneedling did not reach significance. On patient satisfaction, most comparisons showed no difference. No secondary scarring or infection was reported, and post-inflammatory hyperpigmentation favored microneedling.
A 2024 network meta-analysis (Li and colleagues, 24 trials, 1,546 participants) found microneedling combined with something else did better than microneedling alone, with chemical peels plus microneedling ranked first. The combinations it tested included platelet-rich plasma; our PRP microneedling guide covers that one, and microneedling vs other treatments covers peels and lasers.
Two trials show what “works” means in practice:
- Northwestern University, 2014 (Alam et al., JAMA Dermatology). Twenty adults had one side of the face needled with a roller three times, two weeks apart; the other side was the control. Two blinded dermatologists graded standardized photos. Scar scores on the treated side fell by a mean of 3.4 points at six months, a significant change; at three months the 2.4-point drop narrowly missed significance. The control side did not change significantly. Fifteen of the 20 finished.
- The SkinPen De Novo trial (FDA, 2018). Three monthly treatments by a trained aesthetician, depth capped at 1.5 mm, 20 people treated with the final device. On a 0 to 4 scar scale, the mean went from 2.80 to 2.35 at six months. Seven of 20 improved by a full grade, four by less, and “the remaining 9 subjects (45%) reported no change”. Nobody got worse.
Depth matters in at least one comparison. In a 2024 split-face study from Minia University (El-Domyati et al.), 14 people had six Dermapen sessions two weeks apart, at 2.5 mm on one side and 1.5 mm on the other. The 2.5 mm side improved more. That study was done in a clinic; the SkinPen’s FDA summary says safety and effectiveness above 1.5 mm for acne scars “has not been evaluated” for that device. Our depth guide sets out what studies used on each area.
Wrinkles and photoaging
The volume of research is reasonable; the quality is thin. Foppiani’s 2025 review of facial rejuvenation found 21 studies with 723 patients, average age 48, and 83% reported satisfaction. The authors also note that “the lack of standardized measures for esthetic outcomes warrants continued research to better determine its efficacy.” Satisfaction is a different measurement from wrinkle depth.
The most detailed outcome data is the FDA record for one pen. For the SkinPen’s 2021 neck-wrinkle clearance (K202243), 32 people completed four monthly treatments at up to 2.5 mm. Half improved by at least one grade on a wrinkle scale at three months. On the clinicians’ global rating, “57% received a grading of ‘4: no change'”. The same study was published in Aesthetic Surgery Journal in 2022; its first author’s listed affiliation is Crown Laboratories, the company behind SkinPen.
Smaller studies measured the skin directly. An Egyptian study of 10 people with photoaged skin (El-Domyati, 2015) gave six sessions two weeks apart and found more collagen in biopsies afterward, with the authors noting that “multiple sessions are usually needed to maintain the improvement achieved.” A Texas study of 32 people (Wamsley, 2021) gave four monthly treatments to face and neck and measured, by ultrasound, a 101.86% rise in facial dermal density three months after the last one.
Melasma and hyperpigmentation
Here microneedling is almost always studied as a way to push a topical into the skin, most often tranexamic acid (TXA), and the evidence splits on whether the topical matters.
- A 2022 meta-analysis in the Journal of the American Academy of Dermatology (Bailey et al., 12 studies, 459 patients) found a topical plus microneedling beat the topical alone: a moderate extra effect at 8 weeks and a large one at 12 to 16 weeks. The topicals included TXA, vitamin C, PRP and hydroquinone.
- A 2024 meta-analysis of microneedling with TXA (Feng et al., 16 trials) found it beat routine treatment at 4 weeks, but the difference was not significant at 8, 12, 16 or 20 weeks.
- A 2025 meta-analysis (Wang et al.) found microneedling plus TXA no better than other treatments overall, but better than microneedling alone.
- A double-blind Brazilian trial (Kaminski Arida et al., 2021) needled the whole face of 20 melasma patients three times, monthly, then applied TXA to one side and a placebo to the other. Severity fell 29% on the TXA side and 22% on the placebo side, with no significant difference between them.
So the needling may be doing more of the work than the serum, and nobody has settled it. Pigment problems after needling are covered in the safety guide.
Stretch marks
A 2024 meta-analysis (Sun et al., Peking Union Medical College) of 11 studies found microneedling better than non-laser treatments (SMD 1.01) and roughly equal to lasers, with less post-inflammatory hyperpigmentation. It was also more painful than laser. In a Brazilian randomized study of 20 women (Naspolini, 2019), each abdomen was split in half, one side treated with microneedling and the other with a non-ablative laser, for five monthly sessions. Results were similar; pain averaged 5.23 out of 10 for microneedling against 2.39 for the laser. No stretch-mark indication appears among the FDA microneedling clearances.
Hair loss
The randomized trials add microneedling to minoxidil rather than testing it alone. A 2023 meta-analysis (Abdi et al.) of 10 trials found the combination raised total hair count more than minoxidil by itself, without a significant change in hair diameter. A Korean trial of a home-use scalp device (Sohng, 2021, 29 patients) found no statistically significant difference in hair count between groups at six months. Our microneedling for hair growth guide covers the scalp in detail.
How microneedling works, as far as anyone has measured
The theory is collagen induction: the needles cause controlled injury, and the repair process lays down new collagen and elastin while the outer skin layer stays largely intact. The name “percutaneous collagen induction” comes from that idea.
The measured part is narrower:
- Biopsies show more collagen. In Aust and colleagues’ 2008 report, histology on 20 of 480 treated patients showed “a considerable increase in collagen and elastin deposition” at six months and a 40% thicker spinous layer of the epidermis at one year. Those patients had used vitamin A and C creams for at least four weeks beforehand, so the needling was not tested alone. El-Domyati’s two 2015 studies (10 people each) measured more collagen types I, III and VII after treatment, and less total elastin.
- Not every marker moves together. Wamsley’s 2021 study found higher collagen III and elastin gene expression at three months but no change in total elastin protein.
- The link to what you see is inferred. Alster and Graham’s 2018 review in Dermatologic Surgery says stimulation of the wound-healing cascade “is likely responsible for the clinical results”. Biopsy studies are small, and none has shown how much new collagen it takes to change a scar’s appearance.
What a session involves, and how often studies schedule them
The device is passed over the skin at a set depth, and bleeding and redness are on the FDA’s list of common effects. The SkinPen trial numbed the face first. In Alam’s roller trial, participants rated pain at a mean of 1.08 out of 10, while on the abdomen in Naspolini’s trial it was 5.23.
People who try it at home ask the same practical questions. A thread titled “1st at home micro needling” in r/Microneedling has a search snippet recommending lidocaine cream 20 to 30 minutes before needling, applied under plastic wrap. The FDA lists allergy to topical anesthetics among the reasons microneedling may not be suitable.
How often? Trials used one session every two to four weeks, three to six sessions in total, for facial work:
| Study | Condition | Sessions | Interval | Depth or device |
|---|---|---|---|---|
| Alam 2014 | Acne scars | 3 | 2 weeks | Roller |
| SkinPen De Novo 2018 | Acne scars | 3 | Monthly | Pen, up to 1.5 mm |
| El-Domyati 2015 | Acne scars; photoaging | 6 | 2 weeks | Not stated in abstract |
| El-Domyati 2024 | Acne scars | 6 | 2 weeks | Dermapen, 1.5 vs 2.5 mm |
| Wamsley 2021 | Fine lines, face and neck | 4 | Monthly | Not stated in abstract |
| Alqam 2022; SkinPen K202243 | Neck wrinkles | 4 | Monthly | Pen, up to 2.5 mm |
| Kaminski Arida 2021 | Melasma | 3 | Monthly | Not stated in abstract |
| Naspolini 2019 | Stretch marks | 5 | Monthly | Not stated in abstract |
| Dhurat 2013 | Hair loss | Weekly for 12 weeks | Weekly | Roller, with minoxidil |
| Quinlan 2022 | Wrinkles (home use) | Twice weekly for 3 months | 3–4 days | 0.2 mm home device |
Foppiani’s review found that 19 of 21 rejuvenation studies used multiple sessions, with “treatment schedules [that] also varied by number and timing.” We found no trial comparing intervals head to head, so these are the schedules researchers chose, not the best ones. The very short intervals sit only with shallow devices: twice weekly at 0.2 mm in the home study. Healing times after a session are in our aftercare guide.
When do results show?
Months after the last session, in the scar trials.
Alam’s needled side had not improved significantly at three months and had at six. The SkinPen trial’s blinded scar score was 2.68 a month after the final treatment and 2.35 at six months. The melasma meta-analysis found the best results at 12 weeks. The wrinkle studies on this page stopped measuring around three months, so they do not show how long results last.
Microneedling at home vs in a clinic
| Clinic | At home | |
|---|---|---|
| Depth | Trials used up to 1.5 mm (SkinPen, acne scars) and 2.5 mm (Dermapen split-face study; SkinPen on the neck) | Varies by device: the Dermapen HOME is sold at 0.2–0.5 mm, while consumer pens such as the Dr. Pen M8 and Derminator 2 list settings up to 2.5 mm |
| Sterility | Sterile single-use cartridges, prepared skin, trained operator | Depends on the user and the cartridge; some sellers give home re-sterilizing instructions |
| Regulation | All 26 FDA clearances under the microneedling code are prescription-only | The FDA says it has not authorized any microneedling device for over-the-counter sale |
| Evidence | The trials on this page | One 11-person uncontrolled facial study at 0.2 mm; one 29-person scalp trial with no significant result |
The main gap is the evidence. Quinlan’s 2022 home study (Queen Mary University of London) had 11 women use a 0.2 mm device twice a week for three months together with a growth-factor serum. Imaging showed texture improving 17.6% and wrinkles 17.3%, and no serious adverse effects were reported. It had no control group, so the serum and the needling cannot be separated, and 0.2 mm is far shallower than the 2.5 mm maximum that pens such as the Dr. Pen M8 list. No published study compares home and clinic outcomes, or their complication rates.
The argument over home use runs through user forums too. A thread titled “Microneedling at home (advice needed)” in r/Microneedling shows related questions in its search snippet, including “Why are people so against at home microneedling?” and “Is $150 too cheap for a microneedling session ?”.
A clearance for a professional model does not carry over to a brand’s home model: the Dr. Pen A20 is cleared (K230420), the Dr. Pen M8 is not, and the Dermapen HOME is a different device from the cleared professional DP4. Check any device in our FDA lookup, and see what FDA clearance means. For how the three device types differ, read pen vs roller vs stamp; device-level detail is in our reviews of the SkinPen, Dermapen 4, Dermapen HOME, Dr. Pen M8 and Derminator 2. Who should not be needled at all is set out in the safety and contraindications guide.
Why microneedling before and after photos mislead
A marketing before-and-after is one chosen result, and nothing in the picture shows how many people did not get it. The SkinPen trial’s blinded grading found no change in 45% of treated patients. A seller’s gallery would show some of the other 55%.
The photos themselves are easy to bend. Aesthetic medicine has had published standards for before-and-after photography since 1998, and a 2017 proposal to update them (Prantl et al.) gives one reason: digital photography “offers virtually unlimited potential for image manipulation”. A marketing photo comes with no statement of which standard, if any, it followed.
Trials handle this in three ways:
- Standardized photos graded by blinded raters. Alam’s dermatologists did not know which side was treated. The SkinPen trial used two blinded assessors.
- Scales with defined grades. A 2025 review of acne scar outcome measures (Zhang et al.) rated the Goodman and Baron global scarring grading system among the better subjective scales, and named the PRIMOS 3D imager as the strongest objective tool; it also found most scales performed poorly or moderately, largely for lack of reliability testing.
- Separate patient and assessor ratings. In these trials patients were the more generous raters. SkinPen trial patients: 90% reported some improvement, against 55% on blinded grading. On the neck, 68.8% of subjects reported improvement while the clinicians graded 57% as “no change”.
Patient-posted results run the same way. A thread titled “Should I try at home microneedling as a starting treatment…” in r/AcneScars carries a snippet reporting “30% improvement after at home micro-needling sessions!”, a self-estimate rather than a graded one.
When you look at a before-and-after, ask: same light and angle, same time of day, how long after the last session, and how many patients the clinic or brand treated to get it.
FAQ
Does microneedling work? For atrophic acne scars, yes, with modest average gains: randomized trials and a 2022 meta-analysis favor it over comparison treatments, but in the SkinPen trial 45% of patients showed no change on blinded grading. Evidence for melasma, stretch marks and hair loss (with minoxidil) is moderate; for wrinkles it is weak.
How often should you do microneedling? Trials on the face used one session every two to four weeks, for three to six sessions. The only home facial study used a 0.2 mm device twice a week. We found no trial comparing intervals directly.
How many sessions does microneedling take to see results? Most trials gave three to six. In two acne scar trials, the measured change was larger six months after treatment than one to three months after.
Can you do microneedling at home? Devices are sold for it, but none is FDA-authorized for home use and the home evidence is one 11-person facial study at 0.2 mm. The safety guide covers the risks.
Is microneedling FDA-approved? No. “Approval” is the wrong term for these devices. The FDA has 26 clearance records under the microneedling product code, including the SkinPen’s De Novo grant, all for prescription use; the most common indication is facial acne scars.
Sources
- PMID 35426044: Shen YC et al. Microneedling Monotherapy for Acne Scar: Systematic Review and Meta-Analysis of Randomized Controlled Trials. Aesthetic Plast Surg, 2022. https://pubmed.ncbi.nlm.nih.gov/35426044/
- PMID 39110247: Li H et al. Comparing the efficacy and safety of microneedling and its combination with other treatments in patients with acne scars: a network meta-analysis of randomized controlled trials. Arch Dermatol Res, 2024. https://pubmed.ncbi.nlm.nih.gov/39110247/
- PMID 24919799: Alam M et al. Efficacy of a needling device for the treatment of acne scars: a randomized clinical trial. JAMA Dermatol, 2014. https://pubmed.ncbi.nlm.nih.gov/24919799/
- PMID 38159109: El-Domyati M et al. Evaluation of microneedling depth of penetration in management of atrophic acne scars: a split-face comparative study. Int J Dermatol, 2024. https://pubmed.ncbi.nlm.nih.gov/38159109/
- PMID 26203319: El-Domyati M et al. Microneedling Therapy for Atrophic Acne Scars: An Objective Evaluation. J Clin Aesthet Dermatol, 2015. https://pubmed.ncbi.nlm.nih.gov/26203319/
- PMID 40542236: Foppiani JA et al. Microneedling for Facial Rejuvenation: A Systematic Review. Aesthetic Plast Surg, 2025. https://pubmed.ncbi.nlm.nih.gov/40542236/
- PMID 35397167: Alqam M et al. Efficacy and Tolerability of a Microneedling Device for Treating Wrinkles on the Neck. Aesthet Surg J, 2022. https://pubmed.ncbi.nlm.nih.gov/35397167/
- PMID 26096653: El-Domyati M et al. Multiple microneedling sessions for minimally invasive facial rejuvenation: an objective assessment. Int J Dermatol, 2015. https://pubmed.ncbi.nlm.nih.gov/26096653/
- PMID 33656167: A Single-Center Trial to Evaluate the Efficacy and Tolerability of Four Microneedling Treatments on Fine Lines and Wrinkles of Facial and Neck Skin in Subjects With Fitzpatrick Skin Types I-IV: An Objective Assessment Using Noninvasive Devices and 0.33-mm Microbiopsies. Wamsley CE et al. Aesthet Surg J, 2021. https://pubmed.ncbi.nlm.nih.gov/33656167/
- PMID 33857549: Bailey AJM et al. Microneedling as an adjuvant to topical therapies for melasma: A systematic review and meta-analysis. J Am Acad Dermatol, 2022. https://pubmed.ncbi.nlm.nih.gov/33857549/
- PMID 37584240: The efficacy and safety of microneedling with topical tranexamic acid for melasma treatment: A systematic review and meta-analysis. Feng X et al. J Cosmet Dermatol, 2024. https://pubmed.ncbi.nlm.nih.gov/37584240/
- PMID 40555739: Wang Q et al. Combining Microneedling and Tranexamic Acid for Melasma: A Systematic Review and Meta-Analysis. Aesthetic Plast Surg, 2025. https://pubmed.ncbi.nlm.nih.gov/40555739/
- PMID 34077619: Kuster Kaminski Arida D et al. Randomized, double-blind, placebo-controlled split-face trial of the efficacy of tranexamic acid by drug delivery through microneedling in the treatment of melasma. J Cosmet Dermatol, 2021. https://pubmed.ncbi.nlm.nih.gov/34077619/
- PMID 38509316: Sun X et al. Microneedling Therapy for Striae Distensae: Systematic Review and Meta-Analysis. Aesthetic Plast Surg, 2024. https://pubmed.ncbi.nlm.nih.gov/38509316/
- PMID 30618025: Naspolini AP et al. Efficacy of Microneedling Versus Fractional Non-ablative Laser to Treat Striae Alba: A Randomized Study. Am J Clin Dermatol, 2019. https://pubmed.ncbi.nlm.nih.gov/30618025/
- PMID 37665358: Abdi P et al. Efficacy and safety of combinational therapy using topical minoxidil and microneedling for the treatment of androgenetic alopecia: a systematic review and meta-analysis. Arch Dermatol Res, 2023. https://pubmed.ncbi.nlm.nih.gov/37665358/
- PMID 23960389: Dhurat R et al. A randomized evaluator blinded study of effect of microneedling in androgenetic alopecia: a pilot study. Int J Trichology, 2013. https://pubmed.ncbi.nlm.nih.gov/23960389/
- PMID 32516497: Sohng C et al. Usefulness of home-use microneedle devices in the treatment of pattern hair loss. J Cosmet Dermatol, 2021. https://pubmed.ncbi.nlm.nih.gov/32516497/
- PMID 18349665: Aust MC et al. Percutaneous collagen induction therapy: an alternative treatment for scars, wrinkles, and skin laxity. Plast Reconstr Surg, 2008. https://pubmed.ncbi.nlm.nih.gov/18349665/
- PMID 28796657: Alster TS, Graham PM. Microneedling: A Review and Practical Guide. Dermatol Surg, 2018. https://pubmed.ncbi.nlm.nih.gov/28796657/
- PMID 34951101: Quinlan DJ et al. Topical growth factors and home-based microneedling for facial skin rejuvenation. J Cosmet Dermatol, 2022. https://pubmed.ncbi.nlm.nih.gov/34951101/
- PMID 28894653: Prantl L et al. A Proposal for Updated Standards of Photographic Documentation in Aesthetic Medicine. Plast Reconstr Surg Glob Open, 2017. https://pubmed.ncbi.nlm.nih.gov/28894653/
- PMID 39957325: Zhang X et al. Choosing the right outcome measures for acne scar research: a guide for clinicians. Clin Exp Dermatol, 2025. https://pubmed.ncbi.nlm.nih.gov/39957325/
- FDA, De Novo decision summary DEN160029, SkinPen Precision System (acne scar trial: Tables 10–11, blinded and patient assessments; depth statement) (checked 2026-10-06): https://www.accessdata.fda.gov/cdrh_docs/reviews/DEN160029.pdf
- FDA 510(k) K202243, SkinPen Precision System, neck wrinkles (wrinkle scale and clinician and subject global ratings) (checked 2026-10-06): https://www.accessdata.fda.gov/cdrh_docs/pdf20/K202243.pdf
- FDA, Microneedling Devices (no microneedling device authorized for over-the-counter sale; who it may not suit) (checked 2026-10-06): https://www.fda.gov/medical-devices/aesthetic-cosmetic-devices/microneedling-devices
- FDA clearance records for product code QAI: this site’s verification file (26 clearances, all prescription use; indications as recorded), see https://microneedlingreview.com/microneedling-fda-clearance/
- Device depth ranges as quoted from manufacturers and sellers in our reviews: https://microneedlingreview.com/reviews/dermapen-home/, https://microneedlingreview.com/reviews/dr-pen-m8/, https://microneedlingreview.com/reviews/derminator-2/