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Retinoid Cycling


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#1 mitkat

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Posted 22 November 2007 - 08:27 PM


Been doing some research on retinoids and their use over at smartskincare.com, and there is a consensus that under 30 is unnecessary and possibly harmful, by creating a resistance that will rob you of future benefits if using retinoids at a later period in your life, presumably when you've experienced more photoaging.

So my big question, at 26, is it to soon? I've been doing some digging and my preliminary verdict is no, as cycling appears to be a way around building up a tolerance (so to speak) by giving the retinoic acid receptors a break. Sort of a get in, active all receptors by using both tretinoin and tazarotene alternating, do some repair, then stop using regularly until a retinoid is required full-time...which on the conservative tip looks to be like late 30's-early 40's. This cycle could be done several times a year or at key times, ie I've just finished a gov't contract where I spent almost the entire summer outside and experienced a lot of sun, no doubt acquiring damage even with my SPF 50.

Would this cycle however be enough to heal any photoaging significantly, by retinizing the skin and continuing with a program for several weeks and then stopping? Opinions are very welcome as this is a new field to me and I'm probably oversimplifying heaps.

Edited by mitkat, 22 November 2007 - 08:30 PM.


#2 Fredrik

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Posted 23 November 2007 - 05:55 PM

Hi mitkat,

No, there´s no harm in starting a retinoid early and there´s no reason to cycle a retinoid! I´m not sure why anyone would want to claim the opposite. The sooner you start the more photodamage you will prevent, by lessening the UVA-activated MMPs (collagenase and elastase) that break down your skin and creates solar scars (wrinkles).

You won´t create a "resistance" to them other than that the receptors get down regulated and don´t take up all of the the retinoid after about two weeks. That´s a good thing, you won´t get as irritated. But you get all the benefits from then on when your skin is saturated. You should use them as often you can tolerate (1-7 times a week). It´s individual how strong your skin barrier is. A weak skin barrier will absorb more and react with more irritation. But all skin types can be "retinized", if given enough time and patience (read my answer to zoolanders Retin-a/retinoid thread about how to retinize skin gently).

Retinoids are a natural part of your skin. You have retinoic acid in your skin right now. And daylight degrades both the retinoic acid that is stored AND the receptors. Tretinoin, as well as using a sunscreen, prevents both of these things from happening, so topical supplementation with retinoids brings back what is depleted with "age" (that is, amount of UV-exposure).

Most cosmetic dermatologist recommend you start them when your 18, but Albert Kligman, the inventor of Retin-A, says that children of celtic ancestry (red headed, white skin) can start with tretinoin as early as 10 to help prevent possible pre-cancers like actinic keratoses.

Start using that retinoid now and use it indefinitely! It treats and repairs all new photodamage that occurs daily. Your skin and the reflection in your mirror will thank you 6 months from now.

Tip: On pubmed you can find more reliable information than on individual websites like smartskincare.com. Although that one is pretty good, if not entirely updated on how to use retinoids to prevent aging skin.

There´s a good paper on pubmed called "Photoaging: pathogenesis, prevention and treatment". It explains how retinoids not only treat but also prevents aging skin. There´s other good papers, reviews on photoaging if you search on that keyword.

Good luck!

Edited by fredrik, 23 November 2007 - 06:33 PM.


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#3 zoolander

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Posted 23 November 2007 - 11:47 PM

Here was the first study that suggested that retin-A could delay aging of keratinocytes

Biochem Biophys Res Commun. 2000 Feb 16;268(2):268-74.
Retinoic acid extends the in vitro life span of normal human oral keratinocytes by decreasing p16(INK4A) expression and maintaining telomerase activity.
You YO, Lee G, Min BM.Department of Oral Biochemistry and Dental Research Institute, Seoul National University, Seoul, 110-749, Korea.

Retinoic acid (RA) plays an important role in the regulation of cell growth and differentiation. To investigate whether RA extends in vitro the life span of human epithelial cells, we examined the effect of all-trans RA on both the cumulative population-doubling level (PDL) and the replicative senescence of cultured oral keratinocytes. When proliferating oral keratinocytes were cultured in medium containing 1 nM of all-trans RA, the in vitro life span of the cells was increased 1.5- to 1.8-fold compared to the vehicle control and the replicative senescence of the cells was significantly inhibited. Since the replicative senescence of human epithelial cells is associated with a steady increase of p16(INK4A) and a loss of telomerase activity, we expected that RA could delay the replicative senescence of oral keratinocytes by decreasing p16(INK4A) expression and/or inhibiting the loss of telomerase activity. To test this possibility, we examined the expression of replicative senescence-associated genes and the telomerase activities of different PDL numbers of oral keratinocytes exposed to 1 nM of all-trans RA. The protein level of cellular p16(INK4A) in the RA-treated oral keratinocytes was gradually but significantly enhanced by an increased PDL number; however, the level was significantly lower than that of the vehicle control at all of the same PDL numbers. In contrast, the telomerase activity was maintained in oral keratinocytes with increasing PDL numbers induced by RA treatment. Summarizing, these results indicate that RA induces the in vitro life-span extension of oral keratinocytes, which is linked to a decreased cellular level of p16(INK4A) and the maintenance of telomerase activity. Copyright 2000 Academic Press.

PMID: 10679192 [PubMed - indexed for MEDLINE]


and the follow up in 2004

Int J Mol Med. 2004 Jan;13(1):25-31.
Retinoic acid delays keratinocyte senescence by suppression of betaig-h3 and p16 expression and induction of telomerase activity.
Min BM, Oh JE, Choi CM.Department of Oral Biochemistry, Seoul National University College of Dentistry, Seoul 110-749, Korea. bmmin@snu.ac.kr

Retinoic acid (RA) plays an important role in the regulation of keratinocyte growth, differentiation, and senescence; however, the detailed mechanisms of RA regulation are still unclear. To investigate whether all-trans RA extends the in vitro lifespan of normal human epidermal keratinocytes (NHEKs) by affecting mitotic capacity and/or senescence, we studied the effects of all-trans RA on cell growth, senescence, the expression of betaig-h3 and Rb cell cycle regulators, and the telomerase activity of NHEKs after RA exposure. When primary NHEKs were cultured in medium containing 1 nM of all-trans RA, the proliferation and replicative senescence of the cells was significantly stimulated and inhibited, respectively, and the in vitro lifespan of the cells increased 1.4- to 1.5-fold compared to the vehicle control. The levels of betaig-h3 and p16 in 1 nM of RA-treated cells remained significantly lower than that of the vehicle control at all population doublings. All-trans RA also triggered induction of telomerase activity in NHEKs with increasing a population doublings induced by RA treatment. These results support that the ability of all-trans RA to postpone, but not prevent, senescence may be related to both partial inhibition of p16 and betaig-h3 expression and induction of telomerase activity.

PMID: 14654966 [PubMed - indexed for MEDLINE]


and just for the record, from wikipedia,
The keratinocyte is the major cell type of the epidermis, making up about 90% of epidermal cells. The epidermis is divided into four or five layers (depending on the type of skin) based on keratinocyte morphology:

Keratinocytes originate in the basal layer from the division of keratinocyte stem cells. They are pushed up through the layers of the epidermis, undergoing gradual differentiation until they reach the stratum corneum where they form a layer of enucleated, flattened, highly keratinized cells called squamous cells. This layer forms an effective barrier to the entry of foreign matter and infectious agents into the body and minimises moisture loss.

Keratinocytes are shed and replaced continuously from the stratum corneum. The time of transit from basal layer to shedding is approximately one month. Although that approximate time frame can be accelerated in conditions of keratinocyte hyperproliferation, such as psoriasis.

#4 Fredrik

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Posted 24 November 2007 - 12:23 AM

...and here´s the first study that suggested that retinoic acid (tretinoin) could repair and treat aging skin (photoaging). It´s from 1984 :) so although many on this board is excited by retinoids (and they should be!), it´s not exactly new.

Connect Tissue Res. 1984;12(2):139-50.
Topical retinoic acid enhances the repair of ultraviolet damaged dermal connective tissue.
Kligman LH, Duo CH, Kligman AM.

Ultraviolet (UV) irradiation induces excessive accumulations of elastic fibers in animal and human skin. Collagen is damaged and glycosaminoglycans are vastly increased. Formerly considered an irreversible change, we recently showed, post-irradiation, that a band of normal connective tissue was laid down subepidermally . Because of its ability to stimulate fibroblasts and enhance healing of wounds, we thought it likely that retinoic acid (RA) would promote the formation of this subepidermal zone of reconstruction. Hairless mice were irradiated for 10 weeks with Westinghouse FS20 sunlamps for a total UV dose of 7 J/cm2. Then, 0.05% RA was applied for 5 and 10 weeks. Observations were made by light and electron microscopy. In contrast to controls treated with vehicle, the reconstruction zone was significantly wider in RA-treated mice. The enhanced repair was dose related. Histochemically and ultrastructurally, collagen was normal, fibroblasts were numerous and in a configuration of high metabolic activity.

PMID: 6723309

A lot of research followed this, on human and animal skin, where they showed increased collagen synthesis in vivo and repair of UV-damage. If you want to read the early studies search for "kligman" AND "tretinoin" on pubmed. Here is a little more recent summary:

Clin Geriatr Med. 2001 Nov;17(4):643-59
Photoaging: pathogenesis, prevention, and treatment.
Kang S, Fisher GJ, Voorhees JJ.
Department of Dermatology, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA.

Premature skin aging, or photoaging, results largely from repeated exposure to ultraviolet (UV) radiation from the sun. Photoaging is characterized clinically by wrinkles, mottled pigmentation, rough skin, and loss of skin tone; the major histologic alterations lie in dermal connective tissue.

In recent years, a great deal of research has been done to explain the mechanism by which UV induces dermal damage. This research has enabled the identification of rational targets for photoaging prevention strategies.

Moreover, studies that have elucidated photoaging pathophysiology have produced significant evidence that topical tretinoin (all-trans retinoic acid), the only agent approved so far for the treatment of photoaging, also works to prevent it. This article summarizes evidence mainly from studies of human volunteers that provide the basis for the current model of photoaging and the effects of tretinoin.

PMID: 11535421

PS since that was published tazarotene, a selective stronger retinoid with more anti-inflammatory and comedolytic properties, was also approved by FDA for the treatment of aging skin DS

Edited by fredrik, 24 November 2007 - 12:40 AM.


#5 zoolander

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Posted 24 November 2007 - 12:40 AM

Thanks for those articles fredrik

#6 Fredrik

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Posted 24 November 2007 - 01:03 AM

Thanks for those articles fredrik


No prob. I know I´ve been really lazy at digging up the science, providing references to my posts and statements on the treatment of aging skin. I would tire before I got to my point if I had to do that everytime :) My posts are just drawn from my memory of journals and books I´ve read.

I do encourage everyone who´s interested to go to pubmed and use the keywords "aging skin", "photoaging", tretinoin" and "sunscreens" etc because there´s a wealth of research and abstracts that one can learn from (but beware of the many crappy cosmetic lab studies on cell culture out there). I read many full papers back when I studied, now I can only read the abstracts from my home computer, which is maddening.

#7 Fredrik

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Posted 24 November 2007 - 01:43 AM

oh mitkat,
about this sentence in my reply to you: "Your skin and the reflection in your mirror will thank you 6 months from now". That sounded awful, I didn´t mean it like that at all, sorry :) It was just a general comment to anyone who´s reading and thinking of starting on a retinoid, because almost everyone in the second decade of life or older will notice positive changes over time in tone or texture when they start using a retinoid + sunscreen. Your skin, and your smile, looks great!

Edited by fredrik, 24 November 2007 - 01:48 AM.


#8 mitkat

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Posted 24 November 2007 - 04:40 PM

oh mitkat,
about this sentence in my reply to you: "Your skin and the reflection in your mirror will thank you 6 months from now". That sounded awful, I didn´t mean it like that at all, sorry :) It was just a general comment to anyone who´s reading and thinking of starting on a retinoid, because almost everyone in the second decade of life or older will notice positive changes over time in tone or texture when they start using a retinoid + sunscreen. Your skin, and your smile, looks great!


Haha, no worries Fredrik...that never crossed my mind :thumb: Thank you for the compliment!! From the way I understand it, early photodamage is not aesthetic anyways, so as nice as someone's skin would look at a certain age (like the young fair-skinned celt), there is damage occuring that can't be seen.

I have ordered some of the retinoids you're using from ADC and anticipate their arrival next week. Along with Juvess for daily use, I've ordered AlphaHydrox face wash and am still deciding on a new sunscreen. Thank you sincerely for your input on the forums, Fredrik!

#9 Fredrik

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Posted 24 November 2007 - 06:43 PM

Haha, no worries Fredrik...that never crossed my mind :thumb: Thank you for the compliment!! From the way I understand it, early photodamage is not aesthetic anyways, so as nice as someone's skin would look at a certain age (like the young fair-skinned celt), there is damage occuring that can't be seen.

I have ordered some of the retinoids you're using from ADC and anticipate their arrival next week. Along with Juvess for daily use, I've ordered AlphaHydrox face wash and am still deciding on a new sunscreen. Thank you sincerely for your input on the forums, Fredrik!


haha ok, cool :) Looks like your creating a good daily regime to repair daily UV-damage. Remember that you don´t need to use a moisturiser like Juvess or others under your sunscreen if you´re not dry. All sunscreens are moisturising in itself, because they contain emollients and humectants.

If you want topical antioxidants you´re better of with a serum that has a lighter feel without the extra emollients. As you know I think that Skinceuticals C + E ferulic is the most thoroughly researched topical antioxidant protection there is (with both animal and human trials).

I don´t exaggerate when I say that I´ve tried nearly all of the high PPD (PPD 15+) sunscreens for face on the market (with the exception of US Neutrogena and Aveeno sunscreens). So if you listen to me you don´t have to go through the same sticky, messy and expensive trials.

All of them are either a bit whitening or oily looking. I´ve found two that walks the line between these unfortunate features:

Bioderma Photoderm MAX Fluid SPF 50+ and PPD 35
http://www.bioderma....oduct//161.html

AND

La Roche Posay ANTHELIOS XL LSF 50+ PPD 28
Fluide Extreme
http://www.larochepo...;Darreichung=13

The Bioderma is more matte but more whitening and the Anthelios is more shiny but also less whitening. Right now I use the Bioderma except over bearded areas (yes, I don´t shave everyday) where I use the Anthelios, It doesnt cling to hair like the Bioderma.

I believe the Neutrogena and Aveeno sunscreens also have acceptable textures but you´ll have to ask people on this board who use them.

For eye area I use this, because all other sunscreens I´ve tried has irritated my eyes:

http://www.larochepo...p;Darreichung=3

If I may, I suggest you order both the Bioderma and Anthelios cheap from www.cosmetik-paris.com for example (terrible website design but reliable cheap prices and shipping) and compare them head to head.

Edited by fredrik, 24 November 2007 - 06:49 PM.


#10 caston

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Posted 25 November 2007 - 12:12 PM

Fredrik:

Have you read much about people with Xeroderma Pigmentosum using retinoids?

I found one article:

http://content.nejm....act/318/25/1633




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