Editing Intense pulsed light (section)

==Hair removal==
IPL can reduce hair growth, most effectively in darker, coarser hair.<ref>{{Cite news|last=Campbell|first=Leigh|url=https://www.huffingtonpost.com.au/2016/01/07/laser-hair-removal_n_8925010.html|title=The Difference Between Laser And IPL For Permanent Hair Removal|date=2016-01-07|work=Huffington Post|access-date=2020-03-17|language=en-AU}}</ref> IPL is distinct from [[laser hair removal]] which uses coherent [[monochromatic]] laser light.<ref name=":1">{{Cite news|last=Young|first=Katy|url=https://www.telegraph.co.uk/beauty/skin/does-ipl-hair-removal-really-work/|title=Does IPL hair removal really work?|date=2018-04-11|work=The Telegraph|access-date=2020-03-17|language=en-GB|issn=0307-1235}}</ref>

=== Protocol ===
Broad-[[light spectrum|spectrum]] [[light]] is applied to the surface of the [[skin]], targeting melanin. This light travels through the skin until it strikes the [[hair]] shafts or [[hair follicle]].<ref name=":2">{{Cite journal|last1=Husain|first1=Zain|last2=Alster|first2=Tina S|date=2016-02-04|title=The role of lasers and intense pulsed light technology in dermatology|journal=Clinical, Cosmetic and Investigational Dermatology|volume=9|pages=29–40|doi=10.2147/CCID.S69106|issn=1178-7015|pmc=4745852|pmid=26893574 |doi-access=free }}</ref> The follicle is usually where the highest concentration of [[melanin]] is located.<ref name=":0" /> As the light is absorbed, the bulb and most of the hair shaft are heated, destroying the hair-producing [[Papillary dermis|papilla]].<ref name=":2" /> It is also claimed that heat conversion occurs directly in the darker capillaries that bring blood to the follicle.<ref name="Lahiri 55">{{Cite book|last=Lahiri|first=Koushik|url=https://books.google.com/books?id=-HKJDAAAQBAJ&q=The%20area%20to%20be%20treated%20should%20be%20clean%20shaven%20and%20free%20of%20sunburn.%20IPL&pg=PA55|title=Textbook of Lasers in Dermatology|date=2016-07-30|publisher=JP Medical Ltd|isbn=978-93-85999-62-8|pages=55|language=en}}</ref>

At any one time, not all hair follicles are 'active', and only active hair follicles can be affected by the treatment.<ref name=":1" /> 'Inactive' hair follicles can be treated as they become 'active' over time.{{Citation needed|date=March 2020}} For IPL treatments, an average of 8–10 treatments, 4–6 weeks apart, are required to remove most visible hair.<ref name="Lahiri 55"/>

There is no common treatment protocol, as it depends on the equipment used and patient skin type. The area to be treated should be clean shaven and free of sunburn.<ref>{{Cite book|last=Lahiri|first=Koushik|url=https://books.google.com/books?id=-HKJDAAAQBAJ&q=The%20area%20to%20be%20treated%20should%20be%20clean%20shaven%20and%20free%20of%20sunburn.%20IPL&pg=PA55|title=Textbook of Lasers in Dermatology|date=2016-07-30|publisher=JP Medical Ltd|isbn=978-93-85999-62-8|language=en}}</ref>

Although IPL treatments will permanently reduce the total number of body hairs, they will not result in a permanent removal of all hair.<ref name=":3">{{cite journal|last=Klein|first=A.|author2=Steinert, S. |title=Photoepilation with a diode laser vs. intense pulsed light (IPL): a randomized, intra-patient left-to-right trial|journal=British Journal of Dermatology|volume=168|issue=6|date=1 December 2012| pages=1287–93| doi=10.1111/bjd.12182|pmid=23278132|last3=Baeumler| first3=W. |last4=Landthaler|first4=M.|last5=Babilas|first5=P.|s2cid=8889666}}</ref>

Certain skin conditions, health irregularities, and medications can impact whether it is safe for a person to receive a light-based hair removal treatment.{{Citation needed|date=March 2020}} Photo-sensitizing medications, or damage to the skin are contraindications to treatment. According to [[Remington Products|Remington]], manufacturer of an IPL device, all IPL and laser devices should only be used on light to medium skin tones, and work best on darker hair.<ref>{{cite web|url=http://uk.remington-europe.com/microsites/ilight-pro/dr-kubicka-i-light-ask-the-expert/|title=Trends & Tips - Remington|website=uk.remington-europe.com}}</ref>

===Efficacy===
In August 1997, IPL was reported to have permanently removed terminal hair in two patients who underwent multiple treatments to their beards.<ref name=":0" /> In October of that year, the first IPL system developed for hair removal and resulted in 60% hair reduction after 12 weeks.<ref name=DS>{{cite journal|last1=Gold|first1=Michael H.|title=Long-term epilation using the EpiLight broad band, intense pulsed light Hair Removal System|journal=Dermatologic Surgery|date=October 1997|volume=23|issue=10|pages=909–913|doi=10.1111/j.1524-4725.1997.tb00746.x|pmid=9357500|last2=Bell|first2=Michael W.|last3=Foster|first3=Teresa D.|last4=Street|first4=Sherri|s2cid=25398697}}</ref>

It is important to note that these studies utilized a variety of IPL devices on patients with various hair types, skin types, and targeted skin areas. Thus the results are not directly comparable.

According to the FDA, permanent hair reduction means the "long-term, stable reduction in the number of hairs regrowing after a treatment regime." In other words, the number of hairs regrowing must be consistently greater than the duration of the complete growth cycle of hair follicles, which varies from four to twelve months by body location.<ref>{{cite web|url=https://www.fda.gov/radiation-emittingproducts/resourcesforyouradiationemittingproducts/ucm252761.htm#1 |title=Laser Facts |publisher=FDA |access-date=23 September 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140912203435/https://www.fda.gov/Radiation-EmittingProducts/ResourcesforYouRadiationEmittingProducts/ucm252761.htm |archive-date=September 12, 2014 }}</ref> IPL has been found to be much less effective than laser hair removal; however, many patients experience satisfaction with significant hair reduction.<ref name=":3" />

A 2006 article in the journal ''[[Lasers in Medical Science]]'' compared IPL and both alexandrite and diode lasers. The review found no statistical difference in effectiveness, but a higher incidence of side effects with diode laser treatment. Hair reduction after six months was reported as 68.75% for alexandrite lasers, 71.71% for diode lasers, and 66.96% for IPL. Side effects were reported as 9.5% for alexandrite lasers, 28.9% for diode lasers, and 15.3% for IPL. All side effects were found to be temporary and even pigmentation changes returned to normal within six months.<ref>{{cite journal|last1 = Toosi|first1 = Parviz|title = A comparison study of the efficacy and side effects of different light sources in hair removal|journal = Lasers in Medical Science|date = April 2006|volume = 21|issue = 1|pages = 1–4|doi = 10.1007/s10103-006-0373-2|pmid = 16583183|last2 = Sadighha|first2 = Afshin|last3 = Sharifian|first3 = Ali|last4 = Razavi|first4 = Gita Meshkat|s2cid = 10093379}}</ref>

A 2009 study evaluated the rate of hair removal after a second generation IPL source. Results found that patients had 75% hair reduction after four months, and up to 80% after eight months.<ref>{{cite journal|last=Smith|first=S.R.|author2=Y. Tse|author3=S.K. Adsit|display-authors=etal|year=1998|title=Long-term results of hair photo-epilation|journal=Lasers Surg Med|page=43}}</ref><ref>{{cite journal|last=Troilus|first=A.|author2=Troilus C|date=September 1999|title=Hair removal with a second generation broad spectrum intense pulsed light source—a long term follow-up|journal=J Cutan Laser Ther|volume=1|issue=3|pages=173–178|doi=10.1080/14628839950516832|pmid=11360414}}</ref>