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My Story & Routine in Detail

My Story & Routine in Detail Part IV

Evening Part 2:

  • Moisturizer: Paula’s Choice RESIST Super Antioxidant Concentrate Serum OR Peter Thomas Roth Retinol Fusion PM.  This is the same serum as the one I use during the day. The Concentrate is basically a souped-up (and silicone-based) version of the Skinceuticals CE Ferulic serum. In addition to effiacious amounts of vitamins C and E, and ferulic acid, this contains… well basically everything in this ingredient list is a well-documented antioxidant, so I won’t bore you by listing everything. Check Part 2 of my routine for that. The following is a comparison between this product and one by Skinceuticals. Again, feel free to skip it because it is quite tedious.
    • There are some differences however, between the PC product and the Skinceuticals one. One, the forms of vitamin C used are different. PC uses tetrahexyldecyl ascorbate (TA), one of the chemical names for ascorbyl tetraisopalmitate (ATIP), in combination with magnesium ascorbyl phosphate (MAP). Skinceuticals uses ascorbic acid (AA). As shown in Shopping for Skin Care: Get Involved, AA is the most potent form of vitamin C (when in an aqueous solution) because the other two must first be converted to ascorbic acid before they can be utilized by the skin. However, one well-designed study indicates that MAP works just as well as AA when it comes to stimulating collagen synthesis. Furthermore, topical ATIP, has been demonstrated to raise dermal levels of AA more so than corresponding levels of topical AA alone. The downside is that because MAP is a charged molecule, it has some difficulty getting crossing the stratum corneum (SC). Regular exfoliation with something like glycolic acid will thin the SC and therefore allow for greater penetration. On the other hand ATIP, which is lipid-soluble, appears to penetrate well because it easily goes through the lipid bilayers of epidermal cells to reach the dermis.
      • Now PC does not list the concentrations of ATIP or MAP, while Skinceuticals claims that its product contains 15% AA. Therefore, it comes down to whether or not you trust PC or Skinceuticals. For me, it’s simply easier and more fair to take trust out of the equation (or as much as I can). I’d prefer something that lists a specific concentration, rather than something that doesn’t. Point goes to Skinceuticals.
      • Another difference is that the PC product is a silicone-based serum packaged in a tube, while the Skinceuticals product is a oil-in water emulsion packaged in a dropper bottle. The primarily solvent and penetration enhancer of the latter is ethoxydiglycol, a close relative of ethanol. Now, silicone greatly reduces oxidation, while water induces oxidation, although the glycerin content present in the Skinceuticals serum will partially reduce oxidation. But since AA, unlike ATIP and MAP, is very prone to oxidation, the emulsion can only go so far. In addition, while vitamin E and ferulic acid do stabilize AA to an extent, by sharing and balancing electrons, that bonus may be negated due to the dropper packaging. Each time the bottle is opened, the product is exposed to more air, not to mention that after closing the bottle, there is still air trapped in there continuously doing damage. Air induces oxidation because the oxygen atom is extremely “chemically attractive,” due to its high electronegativity. Furthermore AA, after it’s been doubly oxidized, can become pro-oxidative in the presence of free metal ions, instead of antioxidative, meaning that it promotes free radical damage. Note that the PC product also contains vitamins C and E, as well as ferulic acid… and a million other well-documented antioxidants. However, because it has a silicone vehicular base, there isn’t much penetration enhancement, unlike the Skinceuticals version. Furthermore, the forms of vitamin C present in the PC product do not allow for it to regenerate oxidized vitamin E; essentially the antioxidant synergy effect will not be seen with the PC product.
      • Lastly, the Skinceuticals product is about 5.5x more expensive than the PC version.
      • Overall, both serums definitely have their pros and cons and I can’t confidently tell which one is the superior product.
    • The comparison ends here. As I was saying, silicones inhibit oxidation. Not completely, but better than any other vehicular base, with the exception of oil in emulsifying wax. Therefore, it should come with no surprise that the final product by PTR, is a silicone-based serum that allegedly contains 1.5% retinol, which is a huge amount. Although retinol has been shown to be 20x weaker than tretinoin, the active metabolite that the skin can actually use, 1.5% retinol would still translate to roughly 0.075% tretinoin or all-trans-retinoic acid. The highest concentration available for prescription is 0.1%! Tretinoin works by inhibiting the expression of several enzymes that break down elastin and collagen, while increasing the responsiveness of cells to certain growth factors. Furthermore, like carnosine, it has been shown to increase the Hayflick limit in skin cells. That’s crazy right?
      • This also contains some vitamin C, which shouldn’t affect the conversion of retinol since the form ascorbyl glucoside is lipid-soluble, and not dependent on pH for adequate penetration. And the amount of vitamin C present is very little, comparatively. There is also a touch of vitamin E and the anti-irritant bisabolol. Finally, there’s a tiny bit of alcohol, but the amount present is most likely inconsequential. It’s present to act as a formulary solvent and helps in the penetration and delivery of the retinol.
      • I am slightly worried about stabilization issues since this employs dropper packaging and is a water-in-oil emulsion. The dropper packaging is partially inhibited because the retinol is suspended inside water droplets throughout a continuous phase of silicone, which will prevent air from reaching the retinol. However, there’s the issue of the water. I can’t know for sure, but the presence of squalane could indicate that this is actually an oil-in-water-in-oil emulsion, which would protect the retinol from the water content, but that’s all speculation.
      • I think it’s safe to say that overall, this is a fantastic product that is reserved for regular retinol users due to its high retinol content and relatively stable packaging and formulation. First-timer users should start with something that has around 0.25% retinol, and gradually build their way up. Oh, you must be wondering why I included “Nothing” in the Treatment section in Part 3. I did so because when I use the PTR product, I don’t use any chemical exfoliant because the skin requires an appropriately neutral pH (6.5-7.0), to optimally convert retinol to tretinoin via enzymatic oxidation.  Theoretically, you can wait longer between applications in the hope that your skin returns to its regular pH, but why risk it? Besides, the 1.5% retinol will provide plenty of cell turnover (and potential irritation) for your skin to handle. For more information on the retinol conversion process, click HERE.

About John

The Triple Helixian is an unbiased science and research-based site that attempts to clarify and elucidate questions about skin care, while aspiring to be the most thorough and complete source of information.


18 thoughts on “My Story & Routine in Detail Part IV

  1. Hi there,
    I came across your blog as I was looking for some effective acne treatments for my sister. She has been suffering from cystic acne for a few years now (is 27) which has started to flare up again. I believe it is mainly due to her stress level but I also think she needs a proper skin regimen again. I see that you are using a lot of products and my question to you is whether or not you believe she should start off by purchasing all the products you are using or if she should start off with the cleanser,toner and moisturizer first. Any help is greatly appreciated. Thank you

    Posted by Martina | August 7, 2014, 9:19 pm
    • Definitely don’t start off with a too complicated routine. Even for me, I no longer use all these products. I’m not sure if you say, but I haven’t been using this specific routine since a few years ago. I know, I’m way behind on updating everything. But definitely start simple.

      Have her start off with salicylic/glycolic acid and some retinol in the evening. Spot treating with benzoyl peroxide is also an option.

      Let me know how things go!

      Posted by John | September 17, 2014, 4:02 pm
  2. I love your post! It’s so nice to get insight from critical minds and I really appreciate all the effort it must take reading and analyzing hundreds of scientifically credible articles^^ I was wondering about something you said above. You stated: “Although retinol has been shown to be 20x weaker than tretinoin, the active metabolite that the skin can actually use, 1.5% retinol would still translate to roughly 0.075% tretinoin or all-trans-retinoic acid. The highest concentration available for prescription is 0.1%”

    Maybe I’m misinterpreting that, but does that mean that 1.5% retinol is actually more potent than .025% tretinoin? I feel like I must be missing something (or revealing some really embarrassing ineptitude with math and percentages). If that were the case, why wouldn’t 1.5% retinol require a prescription?

    Thanks again for all your thoughtful advice and research 🙂

    Posted by Jane | May 5, 2014, 3:34 am
    • Hi again! Well, theoretically, 1.5% retinol can be stronger than 0.025% tretinoin, assuming the vehicles are similar and properly optimized for each retinoid. That being said however, I can tell you that this Peter Thomas Roth product is definitely quite weak compared to some other OTC retinol products. This is due in large part to the non-aqueous vehicle as well as the improper packaging. If you read the overview of “My Story & Routine,” you’ll notice that I haven’t been using this routine or this product since almost two years ago. I know, I know, I REALLY need to update things!

      But anyways, I wouldn’t recommend this product, at least not over others. But keep using your tretinoin prescription if you’re happy with the results it provides!

      Posted by John | May 16, 2014, 3:34 pm
  3. hi John,

    Just found your blog – thank you! Was wondering your thoughts on this newish PC antioxidant that is water based, although it looks like it still has some silicone: http://www.paulaschoice.com/shop/skin-care-categories/antioxidants/_/RESIST-Ultra-Light-Super-Antioxidant-Concentrate-Serum/

    Should I worry about the water in this product inducing oxidation? Would keeping it in the fridge help at all?


    Posted by Bean | February 19, 2014, 4:44 pm
  4. Is it best to use a Retinol product (I have the Skinceuticals 0.5 Refining Serum) every night if tolerated, or, is it equally effective it i use it on alternate nights (which for me would be alternating with the PC Brightening Serum + the PC 5% AHA Smoothing treatment)? I like all 3 products and the results they achieve. I wouldn’t use any of the PC products in the day since my skin is oily and they are too heavy under my sunscreen. Basically, what is the best way to combine these 3 products to get the best out of them? Thanks

    Posted by Saire | June 25, 2013, 2:54 pm
    • It just depends on your how your skin responds to the products. You have to test out the various configurations for yourself.

      For example:

      1. Do you prefer the effects you get by using retinol every night, and just leaving the 5% out of your routine?
      2. Do you prefer alternating retinol with the 5% every night, and applying the Brightening on top of the 5%?
      3. Do you prefer the effects when you applying the Brightening on top of the retinol instead?
      4. And if it comes to it, while I don’t like recommending the use of retinol with acidic acids (something that will be covered even more extensively in the upcoming Ideal Routine page than before), you might still like the effects of using the 5% and the retinol. The reduced efficacy of the retinol, may allow it to be more tolerable when used on a daily basis.

      Like I said, it really depends on you. Try each configuration mentioned above (and any that you may think of) for perhaps two weeks each. The “best” way to use them on a theoretical level is something that will also be discussed in the Ideal Routine page. I don’t want to tell you now, in case it skews or biases your evaluation of the “trials,” (via a lack of blindness).

      Does that make sense?

      Oh, one more thing. Research does show that if you’ve used tretinoin for about a year every night, you can maintain and sometimes even further improve the results with just 3X weekly application. While the study examined tretinoin specifically, as long as you’re using enough retinol (and a good product of course; the Skinceuticals is a great option), you should get the same or at least similar benefits: http://www.ncbi.nlm.nih.gov/pubmed/9270508

      Posted by John | June 26, 2013, 7:33 am
  5. Hi, John, I have a question.

    “I don’t use any chemical exfoliant because tretinoin is a very large, fragile molecule and any AHA or salicylic acid would render it ineffective.”

    I use tretinoin at 0,05% or 0,1% at night, every other day or overy two days. I thought that using AHA and BHA with retinol was an issue, but not with retinoic acid. I asked at Paula’s Choice chat and they said that it’s actually good to use BHA with tretinoin, due to anti inflammatory property of BHA.

    I wonder why you use retinol, not tretinoin. Is it too irritating for you?

    Also, I would like to hear your input on this product: http://www.paulaschoice.com/product/redness-relief-treatment/toners. It has ascorbic acid, though I don’t think it is in high amounts.

    Posted by Arlon Barbieri | August 20, 2012, 1:22 am
    • Hey thanks for catching this! I said that quote when I first wrote the article, which was probably last year. Back then, I just assumed other people’s information was correct, in this case Dr. Leslie Baumann, and didn’t do my own research. But yeah, tretinoin can be used with acidic products, it’s just retinol, as I said in Part I and II of retinol metabolism. 🙂 But interestingly, about a month ago, I came across an article that said tretinoin worked optimally at a neutral pH &around 7)! But since there was only an abstract available to view for free, I’ll have to get the full article from a friend before letting you guys know my opinion on that particular aspect.

      I just have to edit this entry to reflect updated info. One of these days, I’ll have to go through all the “pages” and add citations, and update everything! But since you brought this one up, I’ll edit it now. Oh, and I don’t use tretinoin because it’s majorly expensive xD.

      As for the relief treatment, the amount of vitamin C present is most likely negligible, since the main focus is the aspirin content. This is further supported by the fact that at higher concentrations, L-ascorbic acid is very irritating in an appropriately low and required pH. Given that this is supposed to calm skin, I’m pretty sure the % isn’t higher than maybe 2%. I looks like an good product that may suit irritated and/or inflammed skin. I believe you told me that you think you have rosacea, and that you’re red, and blush all the time? Based on the ingredients, this may be right for you. Make sure to pick up samples, just in case you don’t like the texture. A few people on the US site, reviewed this product poorly because it left an allegedly greasy residue.

      Posted by John | August 20, 2012, 3:34 pm
      • Thank you!

        I don’t think I have rosacea. I used to use tretinoin every night, which was irritating my skin! As I said before, I now use it every other day or every two days. My skin is much calmer now. I do blush when I’m embarrassed, angry, excited, working out or experiencing some other strong emotion… But I think it’s unrelated to skin irritation or skin care. It’s embarrassing sometimes!

        Posted by Arlon Barbieri | August 20, 2012, 4:39 pm
  6. I cant find the Vit C concentration of the Paulas Choice product and the company does not reveal it. Whats your estimation?.


    Posted by Alejandra | May 7, 2012, 5:47 pm
    • Hi there,

      Yeah, I’ve also asked them for the %, and they refuse to tell me, claiming that it’s “proprietary” information. But anyways, from my best guess, because there are so many other beneficial ingredients present, in order to ensure efficacy of all of them or most of them, the % of vitamin C is most likely not very high. I’d say around 2%. However, keep in mind that the two forms present are lipid-soluble and studies have shown that they are less irritating and penetrate more deeply than the water-soluble L-ascorbic acid.

      However, because the good L-ascorbic acid serums use some kind of penetration enhancer, coupled with a lower pH and high concentration of vitamin C, that may not matter. So I’d say that for an overall antioxidant (prevention) treatment, nothing really beats the Paula’s Choice serum, which has 10+ well-documented antioxidants. However, if you’re looking for a vitamin-C serum to treat existing problems like mild sunspots, fine lines, I’d suggest something a bit more potent, such as the Skinceuticals CE Ferulic Serum. If that’s too expensive for you, there are several other excellent alternatives. My friend Nicki, did a post on this and the link is here:


      When I can, I’m definitely going to try out one of the vitamin-C serums to see if it can enhance my current routine!

      Posted by John | May 7, 2012, 7:02 pm
      • I just saw your comment, thanks John. When i contacted PCs customers service I told them I want a product with at least 5% of vitamin C for the kprf (keratosis pilaris rubra facei) on my face and they said “we cant reveal the amount but with their product I was going to be fine” so it was still an interrogant for me.

        Thanks again, I really like your blog.

        Posted by Alejandra | May 22, 2012, 11:46 am
  7. Thank you for this comparison! i haven’t found any other side-by-side reviews of these products–very helpful!

    Posted by Dena | April 26, 2012, 7:05 am
    • Welcome, welcome! I just wish I could have given you a more definite answer. Both product are excellent in slightly different ways. If you can get your hands on both, I’d love to hear your thoughts!

      Posted by John | April 26, 2012, 8:13 am

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