Safety and efficacy of low-fluence,high-repetition rate versus high-fluence,low-repetition rate 810-nm diode laser for permanent hair removal – A split-face comparison study

Abstract

Background: This study was designed to evaluate the hypothesis that low-level fluences done repetitively on a hair follicle will produce permanent hair removal with less discomfort and fewer side effects than a single high-fluence pulse. Objective: To compare the safety and efficacy of a low-fluence, high-repetition rate versus a high-fluence, low-repetition rate 810-nm diode laser for permanent hair reduction in patients with facial hirsutism. Methods: Forty-two female patients with confirmed polycystic ovaries by ultrasonography with facial hirsutism were subjected to the low-fluence, high-repetition Soprano^® XL laser in SHR mode and the LightSheer? laser on each side of the face using preset parameters once a month for six sessions. Hair counts were done at the end of the sixth session using a ‘Hi Quality Hair Analysis Program System’ and the pain score was recorded by a visual analog scale. Results: The overall median reduction of hair was 90.5% with the Soprano XL and 85% with the LightSheer, with a standard deviation of 7 and 8.5 respectively. Discussion: This new technology, with low fluence and high repetition, showed a statistically insignificant increase in hair reduction compared to the LightSheer, but did show a significant reduction in hair thickness and a low pain score.     

Photoepilation with variable pulsed light in non‐facial body areas: evaluation of efficacy and safety

Background Variable Pulsed Light (VPL?) is a new intensity pulse light (IPL) system. We evaluated VPL for safety and long‐term efficacy in non‐facial hair removal. Study design/material and methods The Variable Pulsed Light [VPL? System (Energist Limited, UK), 610–950 nm] system was used for the removal of unwanted non‐facial dark pigmented body hair in 42 volunteers (40 females, two males, age: 18–43 years, mean: 30.4 ± 7.4 years) with Fitzpatrick skin phototype (SPT) II (33.3%), III (38.1%) and IV (28.6%), and brown (43.8%) or black (56.2%) fine (19.0%), medium (47.6%) or coarse (9.4%) body hair. Minimum follow‐up period was 12 months (mean: 13.14 ± 2.38). Treatment parameters were as follows: number × duration of micropulses: 15 × 5–15 × 7 ms, pulse delay: 1–8 ms, fluence: 30–45 J/cm². Results Very good (≥76% hair reduction) and good treatment efficacies (hair reduction: 51–75%) were observed in the majority of treated patients (n = 18; 42.9%; n = 14; 33.3% respectively), four patients (9.5%) had only moderate (hair reduction: 26–50%) and six (14.3%) patients had no (hair reduction ≤25%) treatment response. Side‐effects (reversible erythema, leukotrichia) were sparse. More favourable long‐term therapy outcomes were observed for higher SPT (III and IV), medium or coarse black hair and younger patients. Conclusion The VPL? System is a relatively efficient and safe treatment for long‐term hair removal. Higher SPT (III and IV) with black and medium to coarse hair, and younger age of the patients appear to be factors of significant importance predicting long‐term efficacy.     

Safety and efficacy of low fluence,high repetition rate versus high fluence,low repetition rate 810-nm diode laser for axillary hair removal in Chinese women

Background: High-fluence diode lasers with contact cooling have emerged as the gold standard to remove unwanted hair. Lowering the energy should result in less pain and could theoretically affect the efficacy of the therapy. Objective: To compare the safety and efficacy of a low fluence high repetition rate 810-nm diode laser to those of a high fluence, low repetition rate diode laser for permanent axillary hair removal in Chinese women. Methods: Ninety-two Chinese women received four axillae laser hair removal treatments at 4-week intervals using the low fluence, high repetition rate 810-nm diode laser in super hair removal (SHR) mode on one side and the high fluence, low repetition rate diode laser in hair removal (HR) mode on the other side. Hair counts were done at each follow-up visit and 6-month follow-up after the final laser treatment using a “Hi Quality Hair Analysis Program System”; the immediate pain score after each treatment session was recorded by a visual analog scale. Results: The overall median reduction of hair was 90.2% with the 810-nm diode laser in SHR mode and 87% with the same laser in HR mode at 6-month follow-up. The median pain scores in SHR mode and in HR mode were 2.75 and 6.75, respectively. Conclusion: Low fluence, high repetition rate diode laser can efficiently remove unwanted hair but also significantly improve tolerability and reduce adverse events during the course of treatment.     

Physiological changes in scalp, facial and body hair after the menopause: a cross-sectional population-based study of subjective changes

Background Significant changes in scalp, facial and body hair occur after the menopause. These can have a significant negative impact on self‐esteem and are also potential markers of endocrine or metabolic diseases. Knowledge of postmenopausal hair changes is important for clinicians to distinguish between normal physiological change and those that require further medical investigation. Objectives To assess the subjective experience of scalp, facial and body hair change in a large cohort of normal postmenopausal females. Methods Postmenopausal females aged 45 years or over of northern European origin completed a questionnaire detailing scalp, facial and body hair changes following the menopause. Women with a history of thyroid disease, oophorectomy or premature menopause were excluded from the study. The Mann–Whitney U‐test and the χ² test were used to assess the correlation between scalp, facial and body hair changes with age. Results Diffuse generalized hair loss was the most common form of scalp hair loss, reported by 26% of women. Frontal hair loss was reported by 9% of women. Facial hair gain was cited by 39% of females with the chin being the most frequent site for new growth (32% of women). Body hair loss was significantly correlated with older age (P < 0·001) and was most frequent at androgen‐sensitive sites. We noted two patterns: (i) diffuse hair loss in which diffuse generalized scalp hair loss was significantly correlated with body hair loss and increasing age (P < 0·05); and (ii) frontal hair loss which was associated with higher facial hair scores and relatively younger age (P < 0·05) compared with women with diffuse hair loss. Conclusions This is the first comprehensive study of the subjective hair changes in postmenopausal women. This study demonstrates two distinct patterns of hair change relating to age, which may reflect different underlying pathophysiological mechanisms and are of relevance to the medical management of these women as well as being possible predictors of health outcomes.     

A randomized double blind,vehicle controlled bilateral comparison study of the efficacy and safety of finasteride 0.5% solution in combination with intense pulsed light in the treatment of facial hirsutism*

Abstract

Objective: We sought to determine whether topical finasteride can enhance the efficacy of intense pulsed light hair removal. Materials and methods: An intense pulsed light (IPL) treatment with radiofrequency (RF) was performed every four weeks, resulting in up to three sessions, and again at the end of the study – 6 months after the start of the experiment. Each patient also applied either finasteride or placebo solution twice daily to each side of the chin in a double-blinded manner. Results: A total of 77 patients were included in the study. Mean hair density before treatment in finasteride side of the patient's chin was 19.7?±?11.7 and in placebo side was 19.1?±?11.3. After three sessions of IPL + RF treatment, combined with twice daily application of finasteride and placebo solutions, at the end of 6-month period mean hair density of 8?±?6.3 and 9?±?5.6 was achieved in finasteride and placebo side respectively. Statistically significant difference was found between finasteride and placebo solution. Conclusions: We have demonstrated that the addition of finasteride solution to IPL + RF hair removal may result in a more reduction of unwanted facial hair in women when the combination is used for up to 6 months.     

Treatment of acne scarring with fractional CO2 laser

Abstract

Background: Fractional ablative CO₂ laser therapy is based on the theory of fractional photothermolysis. It can be effective in treating acne scars in a less invasive fashion than conventional ablative CO₂ laser therapy. Objective: In this clinical study, the safety and efficacy of a novel CO₂ fractional ablative laser was investigated for the treatment of facial atrophic acne scarring in Chinese individuals. Materials and methods: A total of 31 patients (11 females, 20 males, Fitzpatrick skin phototypes III–IV) with facial acne scarring received three sequential fractional treatments over a 6-month period. Outcome measurements included blinded evaluations of before and after photographs by two physicians at 3 and 12 months after the final treatment. Global improvement was noted as well as any untoward events. Results: At the 12 months follow-up time period, 12.9% of the patients showed excellent improvement in their acne scars, while 38.71% noted good to fair results. The clinical response at the 12-month follow-up visit tended to be better than at the 3-month follow-up visit, but was not statistically significant. Four patients experienced post-treatment and transient PIH but three patients were noted to have prolonged erythema. There was no evidence hypopigmentation or worsening of the scarring in any of the study patients. Conclusion: This high-energy pulsed and cool-scanned fractional ablative CO₂ laser system is safe and effective for facial atrophic acne scarring. Improvement in scarring was noted in the majority of patients with minimal discomfort and minimal downtime. Continued improvement over time is also an important clinical finding.     

An efficacy comparison of hair removal utilizing a diode laser and an Nd:YAG laser system in Chinese women

Abstract

Background: The 800 nm diode laser and the 1064 nm Nd:YAG laser have been used successfully for hair removal for many years. Objective: To compare the efficacy of a diode laser with a Nd:YAG laser regarding axillary fossa hair removal in Chinese women. Methods: Twenty-nine Chinese women underwent three treatment sessions at 4-week intervals with a diode laser (34–38 J/cm²) on one side and a Nd:YAG laser (34–40 J/cm²) on the other side. Assessments included the reduction of hair diameter following treatment, the regrowth rate in hair length, total hair reduction and the immediate pain associated with the treatments. Results: At follow-up visit number 1 (4 weeks after the first session), the average reduction in hair diameter on the diode laser side and the Nd:YAG laser side was 2.44 μm and –0.6 μm, respectively. The regrowth rates of the hair were 61.93 μm/day and 59.84 μm/day, respectively, which were not statistically significant (p > 0.05). At follow-up visit number 1, hair reduction was 60.09% and 41.44%, respectively. At follow-up visit number 2 (4 weeks after the second session), hair reduction was noted to be 78.56% and 64.50%, respectively, which were both statistically significant (p < 0.05). Immediate pain scores at the first session were 6.97 and 6.17, respectively; at the second session were 5.48 and 6.69, respectively; and at the third session were 5.76 and 7.45, respectively; all statistically significant (p < 0.05). Conclusions: The diode laser showed more efficacy and was found to be more comfortable than the Nd:YAG laser for axillary fossa hair removal in Chinese women.     

Hypertrichosis in females applying minoxidil topical solution and in normal controls

BACKGROUND: Hypertrichosis has been reported more frequently in females than in males who use minoxidil topical solution (MTS) for the treatment of androgenetic alopecia (AGA). This article examines the occurrence of MTS-induced hypertrichosis in females. METHODS: Data from placebo-controlled clinical trials in females (up to 5% MTS) were analysed based on spontaneous reports of hypertrichosis/facial hair and investigators' inquiries (solicited) about the presence of any new hair growth on body parts other than the scalp. A postmarketing drug surveillance database for MTS was also examined for reports of hypertrichosis/facial hair. RESULTS: In the clinical trials involving a total of 1333 females, spontaneous reports of hypertrichosis/facial hair were noted for 50 (4%) females in a dose-related pattern of response (5% MTS > 2% MTS > placebo). Nine females (seven and two in the 5% MTS and 2% MTS groups, respectively) discontinued treatment because of hypertrichosis/facial hair. Solicited reports of excessive hair growth (primarily facial) also showed a dose-related pattern of response. Post-marketing data showed a lower occurrence (0.5%) of hypertrichosis/facial hair than in the clinical trials. Of interest, in one clinical trial, 27% of the females enrolled (MTS and placebo treated) had facial hair growth reported at baseline. CONCLUSIONS: Females with some hirsutism are particularly prone to seek treatment for AGA, and this may explain the high occurrence of hypertrichosis/facial hair found in the MTS clinical trials. Furthermore, some demographic groups of females are prone to develop facial hair and the problem of unwanted facial hair growth seems to be underestimated. Some females may have hair follicles that are very sensitive to MTS and should use the lowest strength of MTS (2%) to help avoid unwanted hair growth. The hypertrichotic effect of MTS on other sites than the scalp, including the face, is reversible and does not always require discontinuation of therapy.     

The effect of eflornithine 13.9% cream on the bother and discomfort due to hirsutism

Although unwanted facial hair often leads to anxiety and avoidance of social situations, evaluation of treatment outcomes in clinical trials has relied largely on measures external to the patient such as the extent of hair growth or an expert physician's assessment, neglecting to include patient reported outcomes (PRO). To assess the level of bother caused by a dermatological condition (hirsutism) and changes brought on by treatment, the instrument ESTEEM was developed by expanding the Bother Assessment in Skin Conditions (BASC) scale to six questions to cover the discomfort felt in four social situations and bother due to removing facial hair. Each question elicits responses on a visual analog scale. Women participating in two randomized clinical trials evaluated a new treatment (eflornithine 13.9% cream). Analyses examined the level of bother at each visit, the changes with treatment, the correlations with the Physician's Global Assessment, and the effect size. Hirsutism bothers patients considerably. The mean for overall bother was 89% and the mean discomfort in social situations exceeded 80% in nearly all cases. Treatment led to significant reductions in bother on all six items with effect sizes ranging from 0.46 to 1.62. Eflornithine is an effective treatment for unwanted facial hair in women, as reported by the patients. ESTEEM addresses the specific concerns of women with hirsutism.     

Topical Eflornithine

? Eflornithine is a specific, irreversible inhibitor of the enzyme ornithine decarboxylase which is thought to slow hair growth by inhibiting this enzyme in hair follicles. ? Percutaneous absorption of eflornithine in women with unwanted facial hair (hirsutism) was <1% when the 15% cream was applied twice daily to a shaved 50cm2 area of skin under the chin. ? In clinical studies in women with excessive, unwanted facial hair, eflornithine 15% cream was superior to placebo in reducing hair growth, as demonstrated by objective and subjective methods, after 2 to 8 weeks’ treatment. ? After 24 weeks’ treatment, 58% of eflornithine and 34% of placebo recipients had at least some improvement in facial hirsutism (for the purposes of this analysis all patients not assessed at week 24 were considered to be worse or to have no improvement). In addition, 32 versus 8% of patients were judged to be successfully treated (at least marked improvement). Hair growth returned to pretreatment rates within 8 weeks of stopping treatment. ? Use of a self-assessment questionnaire to assess the effect of study treatment on 6 aspects of patient well-being showed that eflornithine reduced the mean level of overall discomfort and bother by 33 versus 15% in placebo recipients. ? Adverse events mostly affected the skin. Only burning/stinging/ tingling was markedly more common with eflornithine than with placebo.     

Hair removal using a combination radio‐frequency and intense pulsed light source

BACKGROUND AND OBJECTIVE: The long‐term removal of unwanted hair is achieved by many laser and intense pulse light sources. One limitation is the treatment of individuals with dark skin. The light energy with the current systems has to penetrate through the epidermis before being absorbed by the hair follicle. In individuals with dark skin the high melanin concentration in the epidermis absorbs high energies that can lead to complications. The objective of our study was to study a new system that combines optical energy, intense pulsed light (IPL), with radio frequency (RF). This allows for the use of less optical energy due to the addition of RF energy. The lower optical fluence allows for safer treatment of darker skin types. STUDY DESIGN/MATERIALS AND METHODS: This was a multicenter study, in which 87 patients were enrolled. A single treatment was performed on a specified body site. Twenty‐one of the 69 subjects that completed the study had skin types IV–VI. Each subject was evaluated at 1, 7, 30, and 90 days after the treatment session. RESULTS: Hair counts were significantly reduced from baseline after one treatment by an average of 46%. Individual patient data showed that the percentage in hair count reduction achieved ranged from 0 to 100%, with 43% of the patients having a 50% or greater decrease. CONCLUSIONS: The combination of optical energy and RF when delivered simultaneously achieves effective hair reduction with the use of less optical energy, allowing for the safe treatment of all skin types.     

A split axilla comparison study of axillary hair removal with low fluence high repetition rate 810 nm diode laser vs. high fluence low repetition rate 1064 nm Nd:YAG laser

Background A low fluence, high repetition rate 810 nm diode laser using constant motion technique has been recently introduced with advantages of less treatment discomfort and fewer side effects compared with traditional laser hair removal. Objective To compare hair reduction and side effects of low fluence high repetition rate 810 nm diode with high fluence low repetition rate 1064 nm Nd:YAG lasers. Methods Forty‐nine subjects were randomly received five monthly treatments with diode laser on one side of their axilla and long‐pulsed Nd:YAG laser on the other side. Hair count was recorded at baseline, 1‐ and 6‐month follow‐up visits. Results Percentage of axillary hair reduction at 1‐month follow‐up visit after receiving diode and Nd:YAG laser treatment were 71.0% and 82.3%, respectively, and at 6‐month follow‐up were 35.7% and 54.2%, respectively. There were significant differences in hair reduction between both laser systems at 1‐ and 6‐month follow‐ups (P < 0.001 and P < 0.001, respectively). Patients reported lower pain on the diode laser side (P < 0.001). Side effects of both laser systems were mild and transient erythema and swelling. Conclusions High fluence low repetition rate Nd:YAG laser was superior in hair reduction and provided higher patient satisfaction. However, low fluence high repetition rate diode laser was less painful.     

Patient satisfaction study of unwanted facial and body hair: 5 years experience with intense pulsed light

OBJECTIVE : This retrospective study was performed in order to evaluate patient satisfaction with epilation using an intense pulsed light source. METHODS : Between 1995 and 2000, 416 patients consulted the authors' practice because of unwanted facial and body hair. A total of 309 patients received treatment with a non-coherent, filtered flashlamp intense pulsed light source. In February 2000, a questionnaire was mailed to each patient and 207 replies were obtained. RESULTS : Overall, 45 (22%) of patients were very satisfied, 93 (45%) were satisfied and 69 (33%) remained unsatisfied with the outcome of light-assisted hair removal. The non-coherent, filtered flashlamp intense pulsed light source satisfactorily removed unwanted dark hair. Hair-free periods from weeks to years could be observed. CONCLUSION : Hair removal by a non-coherent, filtered flashlamp intense pulsed light source is an effective and safe method for long-term epilation of unwanted hair. This technique offers a more reliable and practical solution than any other hair removal method, especially for patients with skin irritation and ingrown hair.     

High-fluence fractional treatment of photodamaged facial skin using a 2940 nm erbium:yttrium-aluminum-garnet laser

Abstract

Introduction: Fractional resurfacing with an Erbium:yttrium-aluminum-garnet (Er:YAG) 2940 nm laser is an increasingly popular option for the treatment of the signs of facial photoaging, which include wrinkles as well as pigmentation issues and unwanted textural changes. Fractional treatment has produced favorable clinical responses, but with less complications and shorter recovery times than traditional laser resurfacing. This study was conducted to evaluate a fractionated Er:YAG treatment regimen of 1–2 higher fluence sessions with a multiple-pass technique. Materials and methods: Eight subjects with moderate to severely photodamaged facial skin received one to two full-face laser treatments. Multiple-pass (MP) treatment results were evaluated in terms of procedure time, discomfort, social downtime and effectiveness. A photographic evaluation, subject improvement assessments and a subject satisfaction assessment were performed. Results: An investigator's photographic review showed a 26–75% improvement in the signs of overall photoaging. Subjects treated with the MP technique exhibited a relatively short 3–4 day downtime and ratings of mostly moderate discomfort with the use of topical anesthetic cream only. Subjects treated with higher fluences demonstrated the highest average improvement in specific features of photoaging. Two laser treatments resulted in substantially higher improvement scores than those received just one laser treatment.     

Alexandrite laser hair removal results in 2359 patients: A Turkish experience

Background: Various lasers have been developed for epilation of unwanted hair. Effective hair removal in the Turkish population can be difficult, and multiple treatments are usually required for effective treatment. Objective: To evaluate the safety and efficacy profile of a long-pulsed alexandrite laser for hair removal in the Turkish population with Fitzpatrick skin types II–V exclusively and to determine the benefit of multiple treatments. Methods: Retrospective clinical evaluation conducted from September 2005 to May 2008 at a referral private clinic. Pre-laser skin testing was performed starting at 16 J/cm² and the energy fluence was selected according to response. All subjects were followed for 6 months after their final treatment. Results: A total of 2359 patients are reported (264 men and 2095 women) ranging in age from 14 to 70 years, for a total of 3830 treatment sites. The majority of treatment sites were axillae (24.2%) followed by the bikini line (16.8%). Maximum reductions observed were 95% for axillae, 92% for the bikini line, 86% for breast, respectively. The patients had a mean 80.6% hair reduction. Complications occurred in only 2.2% of cases. Transient hyperpigmentation (0.7%), folliculitis (0.5%), transient hypopigmentation (0.5%), and blistering (0.4%) were commonly seen complications. No subjects had scarring or long-term pigmentary changes. Conclusion: The long-pulsed alexandrite laser is safe for hair removal in darker skin tones. Although Turkish skin can be effectively treated with a cooled, long-pulsed alexandrite laser, complications do occur.     

Epilation with a long-pulse 1064nm Nd:YAG laser in facial hirsutism

BACKGROUND: Facial hirsutism and hypertrichosis are common problems and a methods are available to clinicians for the unwanted hair in a large number of patients. Several depilatory laser systems are now available and one of these modalities is the long-pulse Nd:YAG laser. OBJECTIVE: To evaluate the efficacy of the long-pulse Nd:YAG laser in removing unwanted facial hair. METHOD: In all, 29 patients completed their treatment course with a long-pulse (4 ms) Nd:YAG (1064 nm line) with fluences between 56 J/cm 2 and 70 J/cm 2 . The average reduction in hair density was assessed using hair count on digital photographs at removal 3, 6 and 9 months postoperatively. The hair-free interval was variety of also evaluated. RESULTS: The average reduction of in the hair count (the same diameter as the baseline for the criterion) was 43% at 3 months, 36% at 6 months, and 46% at 9 months. The hair-free interval with laser was two- to sixfold longer than with self-applied methods. No significant complications were observed in the range of skin types treated, even in the darker skin types. CONCLUSION: The long-pulse Nd:YAG laser is an effective and safe method for long lasting hair removal in all skin types. The delay in hair regrowth most likely explains patient satisfaction.     

Guidelines on the safety of light-based home-use hair removal devices from the European Society for Laser Dermatology

In the past 5 years since their US introduction, there has been a rapid proliferation of light-based hair removal devices intended for home-use. In the last 2 years in Europe, sales already run into many tens of thousands of units with well-known multi-national companies entering the market. These guidelines provide a definition of light-based home-use technology, to inform healthcare professionals about home-use light-based technology and encourage manufacturers wishing to sell in Europe to adopt 'best practice'. The review presents the current status on standards and regulation issues and considers home-use safety issues, encompassing human, device and electrical safety, given risks to the eyes and skin from optical radiation both to the consumer and persons in the vicinity. Proposed technical measurement methodology is considered with focus on recognized critical parameters for the safe use of light-based hair removal technology including recording the technical performance and safety claims of a range of home-use hair removal devices. The literature review emphasizes potential adverse incidents and safety aspects of treating cosmetic conditions, such as unwanted hair growth. Although some regulations exist, they differ from region to region and there is a specific need for international common principles and guidelines relating to the manufacture, marketing and use of intense pulsed light and laser devices, including manufacturing standards for home-use products intended, amongst others, for cosmetic hair removal and photo-rejuvenation procedures. In these guidelines, the European Society for Laser Dermatology (ESLD) provides a professional view of what 'best practice' may imply for manufacturers and consumers alike.     

Split-leg comparison of low fluence diode laser and high fluence intense pulsed light in permanent hair reduction in skin types III to IV

Background/Objectives: All the standard light‐based techniques for permanent hair reduction, like laser and intense pulsed light (IPL) employ the highest tolerable fluence with a single pass. As opposed to standard techniques, a new diode laser technique employs low fluence with multiple passes. Here we evaluate and compare the efficacy, treatment time, comfort and safety of the low fluence multiple pass diode laser with high fluence single pass IPL for permanent hair reduction in Type III to IV Asian patients. Methods: Thirty Asian patients with Type III to IV black hair were enrolled and received three sessions of treatments at 6‐weekly to 8‐weekly intervals. A split‐leg study was performed in which the IPL was applied to one leg of each patient while the laser was applied to the other. The patients were followed up for 12 months. Results: All patients were satisfied with the results of the long‐term hair reduction without long‐term side effects. There was no statistically significant difference in hair reduction and treatment time between the laser (76.85%, 21.39 min) and the IPL (74.53%, 22.17 min) (P > 0.05). The visual analogue scale (VAS) pain score of the IPL (5.96) was higher than that of the laser (3.10) (P < 0.01). Conclusions: A series of high fluence single pass IPL and low fluence multiple pass diode laser treatments were performed with similar efficacy, speed and safety for permanent hair reduction. However, low fluence multiple pass diode laser treatment was less painful than high fluence single pass IPL.     

Clinical and microscopic evaluation of long‐term (6 months) epilation effects of the ipulse personal home‐use intense pulsed light (IPL) device

Background  The aim of this study is to investigate the cellular mechanism of long‐term hair reduction using a novel, square pulse, low‐fluence home‐use IPL device. Methods Ten subjects’ axillae (Fitzpatrick III–V) were treated once weekly for four consecutive weeks in a simulated home‐use trial. Treated and control site punch biopsies were taken from axillary sites for H&E staining and blinded histological examination before, immediately after and six months after the fourth treatment. The contralateral axilla served as a control. Results Histologically, four sequential weekly treatments gave a significant increase in telogen compared with anagen follicles. Six months after the fourth treatment, an 87% reduction in terminal hair count (P ≤ 0.00005) was recorded. An atypical telogen with infundibular dilatation and plugging of keratin and clumping of melanin with disintegration and/or retraction of the intraluminal hair shaft were observed. The papillae remained viable and some new anagen follicles were evident after four treatments. Vellous hairs appeared unaffected by IPL exposures. A mixed inflammatory infiltrate of lymphocytes and eosinophils around vessels of the superficial and deep dermis was sometimes present but the epidermis appeared always normal. Conclusion A highly significant hair density reduction through induction of telogen followed by miniaturization similar to that achieved in professionally delivered permanent laser hair reduction appears to be the major mechanism of hair reduction using home‐use IPL. IPL‐induced damage to the isthmus and upper stem may inhibit or interfere with the hair regrowth process. Longer term studies are required to determine if this observed damage is clinically permanent.