Retinol changes skin on a cellular level. I’m OBSESSED. Here are some options I recommend, before + after pics, safety studies and common myths debunked!
Written by Lisa Fennessy
Reviewed by Kate Noonan, Molecular Biologist and Cosmetic Chemist
Jump to a section to get your questions answered fast!
- Retinol + Retinoids Overview
- How Are Retinols and Retinoids Made?
- Types of Retinol + Retinoids
- Retinol Product Recommendations
- Considerations When Buying and Using Retinol
What’s the difference between the retinol you will find in organic skincare and the retinol you will find in a conventional formula? The short answer is; SO MUCH and NOT MUCH AT ALL. Did that answer all your questions? No? Okay girl, pull up a chair and let’s talk retinol.
Retinoids are popping up with the quickness in the eco-beauty space – and for good reason. One of the most effective treatments for overexposure to UV radiation (AKA premature aging) is retinol. We see it proven again and again in study after study after study.
RELATED: Anti-Aging Skincare Routine
What it all boils down to is; retinoids work. They have many skin benefits including the clinical improvement of fine wrinkles, stimulation of collagen, effectiveness in the treatment of aging and photoaging. But here’s the catch, not all retinoids are created equal. Breaking it all down here so you can choose what’s best for you.
P.S. This post gets a little sciency at times but stick with me! It’s important to understand HOW retinoids work so you can make an informed decision and get the most out of your products. I also want to extend a very big thank you to Kate Noonan who was paramount in making this post come to life.
Retinol + Retinoids Overview
The retinoid family comprises retinoic acid (Tretinoin), Retinaldehyde, Vitamin A (retinol), Retinyl Palmitate, Retinyl Propionate, Adapalene, Tazarotene, and Isotretinoin.
All of these are considered under the umbrella term retinoids.
What’s up with all the derivatives? In short, a lot of it boils down to “retinoic acid conversion”. I asked Susanne Norwitz, founder and formulator of Maya Chia to explain.
“Retinoic Acid is the active ingredient or “the muscle” in retinoids and retinols alike. Retinoic acid works by binding to receptors inside the skin cell nucleus to activate genes promoting skin repair and turnover. Some of these products start out as retinoic acid (like prescription retinoids) and some of these products are converted to retinoic acid (retinols). The shorter the chain of conversion to retinoic acid, the more effective the product. However, when a product starts out as retinoic acid – like many prescriptions – they can be super harsh and have earned a (well-deserved, ahem) rap for being irritating to many people’s skin. Alternatively, when a product has several conversion steps to retinoic acid it lessens its efficacy.”
In short, as consumers, we want a retinol with a “happy medium” retinoic acid conversion chain. Too short of a conversion chain and it’s too harsh. Too long and it’s not effective. It’s important to mark this (AKA “how retinols work at a very basic level) so we can compare different retinoids to each other as well as to plant-based activities.
How Are Retinols and Retinoids Made?
Vitamin A (retinol) is only found naturally in animal and human sources as retinoic acid, retinaldehyde, retinol, and retinyl esters. Retinol does not exist in plants. Plants have β‐Carotene, which is also called pro-Vitamin A, which enzymes in the intestine convert to retinol by oxidizing it. Rosehip also makes a small amount of retinoic acid.
When we see retinol in skincare, or as a topical, it’s typically been lab synthesized with citral from lemongrass or beta-carotene. Then ethanol, potassium hydroxide (used in making wine by the way), and enzymes from plants and microbes are used to complete the final product.
THE TAKEAWAY: If you hear the term “plant-based retinol” it’s pretty much an oxymoron. Retinol can only be lab synthesized (or if you want to get crazy, a chemist could extract retinol from animals and humans but I personally haven’t seen this happening in skincare…yet).
Types of retinol + retinoids you will see on ingredient lists
1. Prescription retinoids
The strongest retinoids are offered through prescription only and tend to be much harsher on the skin like Tretinoin in Retin-A and Retin-A Micro, Adapalene, Isotretinoin, and Tazarotene. These tend to have a shorter conversion chain or no conversion chain at all. Meaning some start out as straight up retinoic acid.
I don’t know about you but personally, my brain defaults to “stronger = better”. Stronger coffee, stronger muscles, stronger probiotics…stronger margaritas. For me it’s an instant gratification thing. I want results and I want them NOW. The same applies when it comes to skincare. Me: Apply blemish cream, look at blemish 5 minutes later. Blemish is still huge. Damn blemish cream to all hell. Can anyone relate?
But with retinol, stronger does not equate to “better” or “more effective”. Here are a couple of examples of how prescription retinoids compare to non-prescription retinoids in double-blind, controlled clinical studies:
Retinaldehyde (OTC with 1 step conversion) compared to Tretinoin (prescription with zero steps conversion)
When Retinaldehyde (which by the way, is what we see in the new African Botanics Retinal Night Cream) was compared to prescription Tretinoin, studies have found comparable clinical improvement across the board including; repairing skin damage, reducing wrinkle depth, improving skin texture, increasing hyaluronic acid synthesis, restoring skin elasticity, and reducing hyperpigmentation (3, 4, 5, 6).
So what’s up for debate? Well, here’s where (OTC) Retinaldehyde and (prescription) Tretinoin differ. Tretinoin may produce slightly better results (although not statistically significantly different) but it causes patients some irritation while Retinaldehyde does not (6). Kate Noonan, Molecular Biologist and Cosmetic Chemist, explains Retinaldehyde and retinol topicals do not overload the receptors like Tretinoin does; “When Retinaldehyde or retinol are applied to the skin, in vivo human research has confirmed skin cells convert it into retinoic acid that completely binds the skin cell nuclear receptors to activate skin repair and hyaluronic synthesis without overloading these receptors and causing the irritation seen with Tretinoin” (6, 7).
Similar results were noted in studies comparing retinol to tretinoin (7, 8, 9).
THE TAKEAWAY: All of this to say, save yourself the trouble of considering prescription strength retinoids because you can get similar results with retinol minus the irritation.
2. Various types of retinol
Then there are various types of retinols, (Vitamin A derivatives) that convert to retinoic acid once applied to the skin. These will most likely be written as “retinol” on an ingredient label. From what I’ve used, the most effective retinols have a one or two-step conversion process like Retinaldehyde or retinol.
3. Vitamin A esters
And then there are also various “esters” of Vitamin A that are still classified as retinols like Retinyl Acetate, Retinyl Linoleate, Retinyl Propionate and Retinyl Palmitate. Susanne Norwitz adds, “These derivatives have longer conversion chains into retinoic acid – which has significant implication for their overall efficacy. Many of these retinoids are also unstable when exposed to sunlight and air. It is also important to note that of these derivatives, Retinyl Palmitate specifically, has been linked to one study to the enhancement of tumor growth in mice when exposed to UV rays.”
Speaking of that one study, here it is, and almost every warning you will find on the internet saying retinol causes cancer or tumors seems to point to it.
For example, MADE SAFE reports that some forms of Vitamin A can be harmful like Retinyl Palmitate and retinoic acid which are both associated with photocarcinogenicity (or the potential to cause cancer when exposed to sunlight). MADE SAFE bans all Vitamin A derivatives from their certification process.
Nneka Leiba, vice president of EWG’s Healthy Living Science Program weighs in referencing the same study stating, “Retinol is an antioxidant ingredient used in skin products because manufactures believe it slows aging. Studies by the U.S. government suggest that retinol and other retinoids may speed the development of skin tumors and lesions when applied to sun exposed skin.”
But the thing that no one talks about is that this study was compromised by the addition of mouse-specific carcinogens in the control cream and all the creams tested.
This NTP TR568 government study (10) the EWG mentions was compromised by having four known mouse carcinogens added to the Tretinoin and Retinyl Palmitate creams and two mouse carcinogens in the control cream. The mouse carcinogens were BHT, BHT-quinone, diazolidinyl urea (DZU), and diisopropyl adipate (DIA) (11-20).
Every NTP Expert Peer Review Panel primary reviewer, Drs. Rice, Cattley, Klaunig, and Smart concluded, “The conclusion of photocarcinogenicity was not sufficiently supported by the data”, due to the addition of ingredients that compromised the experiment and DIA also caused the mice to scratch themselves intensely, an activity that has been proven in mice to cause skin cancer (10, 21).
And, to top that off, the 2016 EU Government’s Scientific Committee on Consumer Safety (SCCS) Expert Panel concluded that the NTP TR568 study was flawed and they found retinol, retinaldehyde, and retinyl palmitate safe and not phototoxins or carcinogens (11).
In fact, extensive human studies, clinical trials, and epidemiological data support both the safety and efficacy of retinol and retinaldehyde (22-30).
There was so much data we found on this, I could talk all day about it but for the sake of staying on track, let’s continue on….
Eco/clean/green/organic beauty formulators weigh in….
To add some color, I also checked in with a couple of well-renowned eco-beauty formulators to get their stance on retinol and this is what they had to say.
Josh Rosebrook, founder and formulator of Josh Rosebrook says, “There are decades of study behind retinol showing its efficacy. Retinol is safe, it’s an incredibly effective, sustainable active in skin care today.”
Laurel, founder and formulator of Laurel Skin says, “I do believe not all retinols are created equal. Some appear to be gentler on the skin and more effective than others. And I’m sure to the surprise of many, no, I do not believe their gentleness, safety or efficacy has anything to do with them being natural or plant derived versus synthetic. Many plant derived isolated chemical compounds can actually go through more chemical processing than a manufactured synthetic ingredient. In fact, when it comes to isolated chemical compounds, I am often more likely to trust a synthetic ingredient than a new or trending ‘plant derived’ one based on the synthetic’s history of safety, history of efficacy – because again both are chemically processed and there is not enough plant resemblance there for me to feel one is more ‘natural’ than another.”
Susanne Norwitz, founder and formulator of Maya Chia says, “Retinol is the gold standard in inhibiting the breakdown of collagen, increasing collagen synthesis, increasing skin elasticity, helping to seriously address the signs of photo-aging in the skin and regulating sebum production. It is one of the most studied ingredients in skincare. There is a spate of literature to affirm its effects – but the landscape is rife with confusion.”
Marie Veronique, a chemist with degrees in Math and Science, a trained esthetician and founder of Marie Veronique says on her website, “Unfortunately, the retinyl palmitate cautionary has convinced watchdog groups to warn people off of all forms of topical vitamin A, which is unfortunate because forty years of studies support the benefits of retinol and retinoic acid. Vitamin A is essential for normal skin differentiation and development, increases elasticity and collagen synthesis, improves water barrier properties and is the only substance we know of that reverses signs of photo-aging.”
Formulating with retinol is trending in organic/eco/clean beauty and I predict this is just the beginning. I’m personally excited to see more brands incorporate it in new and innovative ways. And I’m kinda on the edge of my seat like; What’s next?!
And lastly; Vitamin A in plants
Okay, we’ve talked about synthesized retinoids but what about pro-Vitamin A in say carrots or Vitamin A in Rosehip Seed Oil? Do these also act as retinol/retinoids?
Okay so there are two angles here. We can talk about what happens to pro-Vitamin A in carrots (also called β‐Carotene) when it’s applied topically OR when it’s digested. For the sake of this article, we want to talk about topicals so here’s the scoop.
Josh Rosebrook says, “Vitamin A as β‐Carotene in plants applied topically does not deliver results comparable to clinical trials and studies utilizing lab synthesized retinol.”
That’s because when β‐Carotene is topically applied, human skin research shows it is mostly stored as retinyl ester molecules and there isn’t activation of the retinoic acid receptors to have the skin benefits of topical retinaldehyde and retinol (30, 31, 32).
We also see Vitamin A in carrier oils like Rosehip Seed Oil. Susanne Norwitz adds, “Another common misconception is that Vitamin A carrier oils (such as Rosehip Seed Oil) on their own are comparable in efficacy to Retinol/Retinoid products.” Kate Noonan confers, “The oil of Rosehip contains a little retinoic acid but it’s a variable amount and I’ve noticed this oil doesn’t have the same results as using a dedicated retinol or retinaldehyde product.”
THE TAKEAWAY: Vitamin A carrier oils and β‐Carotene in plants are not comparable in efficacy to retinol products.
That being said, it’s also not always an apples to apples comparison. Laurel of Laurel Skin adds some color, “While it’s indisputable that retinol offers skin benefits, we have found that it is possible to achieve equal result with whole plant formulas. It’s not like comparing apples to apples and only considering the percentage of one compound (like retinol) or in this case comparing isolated retinol to the percentage of retinoic acid in Rosehip. It’s instead about the overall effect of how ALL the presenting phytochemicals work in tandem together.“
Back to retinol…
For the purpose of this conversation, I want to talk about straight up retinol. That’s the retinoid derivative I’ve seen emerging in eco-beauty to date. I personally wouldn’t recommend using prescription strength retinoids because of the irritation they can cause or esters like retinyl acetate, retinyl linoleate, and retinyl palmitate because the body does not convert enough of it to retinoic acid for it to work. That leaves us with retinol. Here is an overall pro and con list to keep in mind when shopping retinols.
2. Retinol is a sustainable ingredient.
1.You have to choose wisely. Some retinoid products on the market contain questionable preservatives and other additives such as BHA, BHT, parabens, and diazolidinyl urea in their formulations – we can see these listed on the ingredient label. It’s interesting to note, BHA is on the Prop 65 list for cancer while BHT (a related plasticizer compound that has a note on the WHO and Prop 65 websites) is not on the Prop 65 list itself but there is an acceptable daily intake (ADI). The ADI is there because BHT and its metabolite BHT-quinone are used as a rodent carcinogens in research (34-38).
2. Not only are some serums, creams and formulas preserved questionably BUT many RAW MATERIALS contain BHA or BHT– if these are added during processing, BHA and BHT will not always appear in the final ingredient list unless the brand is transparent.
Look for these options that are made BHA-free and BHT-free: “Retinaldehyde”, “Phospholipids (and) Retinol” (liposomal retinol or encapsulated retinol), and “Retinol” with “Soybean Oil” or “Tocopherol” in the formula.
If BHA was added during processing to retinoids, companies are required to have a Prop 65 warning on their website and box for CA customers–but some may not be compliant. Since BHT in a raw material won’t be accompanied by a Prop 65 warning, see if the brand states that no BHT was added as well. This also may mean emailing or calling a brand to confirm.
3. Retinoids come in all different strengths. For example, Tretinoin is 20 times stronger than retinol. It’s not always as simple as picking a retinoid off the shelf and using it.
4. Recommended to avoid during pregnancy. Tretinoin is on the Prop 65 list for risk of pregnancy teratogenicity (an agent that can disturb the development of the embryo or fetus) but it is not listed on Prop. 65 for cancer. It is not listed on the WHO’s carcinogen list. The Ames and in vivo Micronucleus tests for retinoic acid, Retinaldehyde, and retinol confirmed no mutagenic activity. The reason for the birth defect risk with Tretinoin use is that retinoic acid signaling must be tightly controlled during embryonic brain development and this process cannot have any outside Tretinoin added to the equation or the embryo will develop abnormally.
So the cool thing is, the choice is yours. If you want the power of a synthetic retinol but don’t want all the junk that comes with traditional prescriptions or OTCs – it’s out there. I’ve tried a handful of formulas with retinol in eco beauty and I definitely have some favorites. Here’s my take.
Synthetic retinoids are an instant gratification junkies dream come true. They work practically overnight and they are so satisfying to use. I saw a difference in my skin in just 3 days with one of the African Botanics products and most recently it was practically a matter of minutes with Maya Chia’s latest; The Straight A.
RELATED: Read my full Maya Chia review here.
My biggest piece of advice when using retinol is to ease into it. Retinols change the skin on a cellular level. They are LEGIT.
I consider my skin to be pretty normal. It’s definitely NOT sensitive. But I do have hyperpigmentation and occasional seasonal dryness. Almost every time I have used a synthetic retinol (in a clean beauty formula), I’ve had to back off. As the days pass, my skin gets this dry feeling – not visibly – but I can feel it. It’s a little more unquenchable. Slightly irritated. Just slightly. BUT, that being said, my skin looks brighter, more even, it has less hyperpigmentation…I mean, the results are undeniable. Brilliant actually.
Check out these before and after photos.
I know the lighting is off here. All photos are unfiltered and unedited. I tried my best to get two photos with similar lighting. I really tried! But lighting and warmth aside, check out fine lines around my eyes above. Compare the evenness of my skin tone. Do you see a difference? I sure do.
Here are the un-cropped photos below for additional comparison.
At this point, do I even have to say it out loud? I’m OBSESSED with retinol.
Formulas with retinol I recommend…
Maya Chia’s The Straight A
The Straight A is a big-time powerhouse. It’s formulated with retinol as well as what some in the industry are calling “phyto-retinols” like Bakuchiol. This is an oil serum. I prefer it layered under my moisturizer but you can also use it straight up as a moisturizer too.
Founder Susanne Norwitz says “Phospholipids & Retinol is the INCI name on the package. ‘Retinol’ is the scientific name and it’s combined with phospholipids (encapsulation for a slow release of retinol) in a carrier oil.” But that’s not all it’s got up its sleeve. This formula also includes an oil soluble, shelf-stable Vitamin C, Vitamin E AND Bakuchiol as well as Moth Bean Extract to augment the effects.”
I asked Susanne what her motivation was to develop The Straight A and she said, “I just really wanted to make a product that was not totally cost prohibitive and yet people could really see substantive benefits.”
Also, remember when we were talking about finding that happy place in the retinoic acid conversion chain? Susanne says, “The Encapsulated Retinol we use has a two step conversion process into Retinoic Acid – making it the most efficacious kind of Vitamin A derivative without the associated irritation of a prescription retinoid.”
And let me tell you, she did. I got The Straight A about a month before it was released and so I’m able to share these before and afters with you. A couple of things. I noticed a difference in my skin within the first few days of using The Straight A. It was brighter, more even and my hyperpigmentation had faded a bit. Susanne said she formulated The Straight A with a maximum percentage of retinol and I can totally feel it. I found my sweet spot at about 3 days a week or every other day if you will.
RELATED: Read my full review about the Straight A here.
This is a 30 day before and after using The Straight A. Befores are on the left. Afters are on the right. All photos are unedited and unfiltered. In this first pic, check out the fine lines around my eyes. You can see they are less pronounced and more filled in. I think I just found my new “eye cream”!
And in this next photo, check out the consistency of my large hyperpigmentation spot. The density has shifted and I can see signs of it breaking up. Can you?
PROS: Price, a tricked out formula, beautiful scent and consistancy, effectiveness.
CONS: I couldn’t use it daily. BUT Susanne said she amended the formula slightly after I tried it and this has been rectified.
And I’m not the only one who thinks so…check out what readers on Instagram said when I polled my stories!
African Botanics (several options)
African Botanics formulates with clean ingredients while drawing on the power of retinol too. We see retinol in several of their formulations. This is one of the most exciting lines I tried in 2019 and I’ve talked about them a ton. Why? Because they are results driven. Below are my two African Botanics faves. I do want to mention, some African Botanics’ formulas are preserved with phenoxyethanol so be sure to glance at the ingredient list first if that’s important to you. These two are not.
I talked to African Botanics founder Julia Noik and she explains the retinol used in both of these serums below is a synthesized pro-vitamin A from carotenoids that has a two-step conversion process.
1.Fleurs D’Afrique Intensive Recovery Oil
Fleurs D’Afrique Intensive Recovery Oil oil blew me away. I saw a difference in my skin in just three days and that’s not an exaggeration. I wish I took before and afters to share with you here. But I had never seen results like this in clean beauty before so it was totally unexpected. This formula contains retinol which is supported by an ultra stable and oil soluble Vitamin C ester. This plus CoQ10 to help neutralize free radicals, support the building of collagen, and reduce hyperpigmentation.
One look at the ingredient list and you will be sold. Not only does each ingredient supersede the next, it’s an effective blend of science and naturals. The formula as a whole is brimming with botanics like African Bush and desert plants to help speed recovery and skin regeneration. And on top of that, it’s enhanced with technology like Blue Marine Microalgae Extract – a powerful, anti-wrinkle marine micro algae. As a whole, it’s rich in antioxidants, amino acids, Omega 3/6/7/9s, vitamins, minerals, peptides and more.
This is an oil-based serum and no water or humectants (water attracting ingredients).
When I had a bottle, I liked using about 5 drops nightly as a serum layered under my moisturizer.
PROS: I found I could wear this nightly without any irritation. This oil is pretty much a miracle worker.
CONS: The price. And the smell. For me this hit notes of the 8th arrondissement on market day. It’s pretty pungent.
I asked founder Julia Noik about the price of this serum. Here’s what she had to say, “The Intensive Recovery oil price is based on the price of the ingredients and the method at which it was produced. Maceration of botanicals is timely, the ingredients are very unique and of the highest quality.”
2. Resurrection Cell Recovery Serum
I tried African Botanics Fleurs first and then I tried their Resurrection Cell Recovery Serum and all of a sudden I had these two competing for top spot.
This is a light, liquid, gel serum that you layer under your moisturizer that increases collagen synthesis and reduces fine lines. Plus it also works to restore moisture loss, plump and protect.
But what I really love about this formula is the addition of Swiss Garden Cress Liposomes to help brighten the skin by inhibiting melanin production in the skin. It also helps lighten post sun damage and post scars/ blemishes. I got a blemish last week and I never touched it and it still turned into a dark spot. Please tell me this is not a symptom of being 41. Every blemish turns into a dark spot now?!
It also contains Resveratrol, Hyaluronic Acid, Vitamin B 5, Peptides, Centella Asiatica, Arnica, Cucumber extract and African Aloe Ferox. This serum will help plump the skin and infuse it with lots of moisture at the same time.
The retinol in this serum may be sightly more effective. Founder Juila Noik explains, “The retinol is the same in both African Botanics’ formulas but it is known that retinol in gel based formulas would be more active since there are no buffering oils like in oil based serums or creams.”
I love layering 1-2 pumps of this under my moisturizer.
PROS: I could use this nightly without any irritation. I LOVE that it’s a gel serum as opposed to an oil. It’ sinks right in when applied.
CONS: At $160/1oz it’s an investment.
*I also tried doubling down by layering these two African Botanics’ formulas and it was too much for my skin. One is enough.
Try Resurrection Cell Recovery Serum here!
Considerations when buying and using retinol
1. Work your way up. Start using retinol a couple nights a week and if your skin feels good, increase usage in increments.
2. Avoid health compromising ingredients. Look for formulas that avoid preservatives such as BHA, BHT, diazolidinyl urea, parabens like methylparaben, ethylparaben, propylparaben, butylparaben, isopropylparaben and isobutylparaben and synthetic fragrance which is usually listed as “fragrance” on the ingredient label.
3. Use a broad spectrum SPF sunscreen. Do this anyway whether using retinol or not. Sunscreen use stops photodegradation of your skin’s own antioxidants. Even a few minutes of sun without sunscreen on skin causes DNA damage and damage to structural proteins (39).
4. It’s not for night time only. Contrary to popular belief, retinol does not make skin more photosensitive or affect the minimal erythema dose (MED) (40). There are some things people put on their face during the day that are phototoxic like non-FCF-free bergamot with bergapten, cold-pressed lemon oil, mandarin essential oil, or carrot essential oil. Retinol is not one of them.
5. Maximize your skin’s night time regeneration. That being said, it’s still recommended to use retinol at night because research indicates this takes advantage of skin’s regeneration being at its highest (41, 42). And when you are spending a Benjamin or two on your serum, you want to get the most out of it!
6. MYTH: Retinols thin the skin. They don’t. Actually, they do the opposite. Photo-aged stratum corneum and epidermis is structurally disordered and weakened with fissures from sun damage. Retinoid topicals improve the structural organization of the stratum corneum and epidermis and improve epidermal thickness. The improvements in the stratum corneum organization help its role in protecting the epidermis from UV (43-52).
7. If you are experiencing irritation, try applying to dry skin. It is best to apply retinoids at least 30 minutes after washing the face or face misting to avoid irritation. (33) If you are not experiencing irritation, you do not have to do this.
8. Don’t waste your money on vitamin A esters. These derivatives have longer conversion chains into retinoic acid which has significant implication for their overall efficacy.
9. Prescription retinoids are not required to get effective results.
10. Consult a doctor if you are pregnant.
11. Consistency and patience is key. Know that retinol does work so if you stick with it, you will see results.
For more, check out my evening skincare routine!
1. Schwartz, S.H.; Qin, X.Q.; Zeevaart, J.A.D. Characterization of a novel carotenoid cleavage dioxygenase from plants. J. Biol. Chem. 2001, 276, 25208–25211.
2. Nacke, C.; Hüttmann, S.; Etschmann, M.W.; Schrader, J. Enzymatic production and in situ separation of natural β-ionone from β-carotene. J. Ind. Microbiol. Biotechnol. 2012, 39, 1771–1778.
3. Kwon HS, Lee JH, Kim GM, Bae JM. Efficacy and safety of retinaldehyde 0.1% and 0.05% creams used to treat photoaged skin: A randomized double‐blind controlled trial. Journal of cosmetic dermatology. 2018 Jun;17(3):471-6. https://doi.org/10.1111/jocd.12551
4. Creidi P, Humbert P. Clinical use of topical retinaldehyde on photoaged skin. Dermatology. 1999;199 (Suppl. 1):49-52. https://doi.org/10.1159/000051379
5. Creidi P, Vienne MP, Ochonisky S, Lauze C, Turlier V, Lagarde JM, Dupuy P. Profilometric evaluation of photodamage after topical retinaldehyde and retinoic acid treatment. Journal of the American Academy of Dermatology. 1998 Dec 1;39(6):960-5. https://doi.org/10.1016/S0190-9622(98)70270-1
6. Nadal-Wollbold F, Viode C, Alvarez-Georges S, Lejeune O, Josse G, Casas C, Mengeaud V, Redoules D, Schmitt AM. In vivo retinoid molecular profile of retinaldehyde in human photoaged skin. Journal of Dermatological Science. 2016 Oct 1;84(1):e34-5. https://doi.org/10.1016/j.jdermsci.2016.08.113
7. Shao Y, He T, Fisher GJ, Voorhees JJ, Quan T. Molecular basis of retinol anti‐ageing properties in naturally aged human skin in vivo. International journal of cosmetic science. 2017 Feb;39(1):56-65.
8. Kafi R Kwak HSR Schumacher WE et al. Improvement of naturally aged skin with vitamin A (retinol). Arch Dermatol 2007;143:606-612. https://doi.org/10.1001/archderm.143.5.606
9. Babcock M, Mehta RC, Makino ET. A randomized, double-blind, split-face study comparing the efficacy and tolerability of three retinol-based products vs. three tretinoin-based products in subjects with moderate to severe facial photodamage. Journal of drugs in dermatology: JDD. 2015 Jan;14(1):24-30.
10. Boudreau, Mary et al. NTP (National Toxicology Program). 2011. Findings of NTP Board of Scientific Counselors on Retinoic Acid and Retinyl Palmitate – TR 568. Meeting, January 26, 2011. Research Triangle, North Carolina. Available: https://ntp.niehs.nih.gov/ntp/htdocs/lt_rpts/tr568_508.pdf
11. Bernauer U, Bodin L, Celleno L, Chaudhry Q, Coenraads PJ, Dusinska M, Duus-Johansen J, Ezendam J, Gaffet E, Galli CL, Granum B. Scientific Committee on Consumer Safety SCCS OPINION ON Vitamin A (Retinol, Retinyl Acetate, Retinyl Palmitate). https://ec.europa.eu/health/sites/health/files/scientific_committees/consumer_safety/docs/sccs_o_199.pdf
12. Pfuhler S, Wolf HU. Effects of the formaldehyde releasing preservatives dimethylol urea and diazolidinyl urea in several short-term genotoxicity tests. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 2002 Feb 15;514(1-2):133-46. https://doi.org/10.1016/S1383-5718(01)00335-7
13. Alavi MS, Shamsizadeh A, Karimi G, Roohbakhsh A. Transient receptor potential ankyrin 1 (TRPA1)-mediated toxicity: friend or foe?. Toxicology mechanisms and methods. 2020 Jan 2;30(1):1-8.).
14. BHT and BHT-quinone, mouse carcinogens: S. Oikawa, K. Nishino, S. Oikawa, S. Inoue, T.Mizutani, S. Kawanishi. Oxidative DNA damage and apoptosis induced by metabolites of butylated hydroxytoluene. Biochem. Pharmacol., 56 (1998), pp. 361-370, 10.1016/S0006-2952(98)00037-9
15. F. Nagai, K. Ushiyama, I. Kano. DNA cleavage by metabolites of butylated hydroxytoluene Arch. Toxicol., 67 (8) (1993), pp. 552-557, 10.1007/BF01969268
16. Moch RW. Pathology of BHA-and BHT-induced lesions. Food and Chemical Toxicology. 1986 Oct 1;24(10-11):1167-9.
17. Al-Akid YF, El-Rahman AE, Hussein HA, Wassif GA. Nephro-and pneumotoxic response to chronic administration of butylated hydroxytoluene (BHT) in adult albino rats. Al-Azhar Journal of Pharmaceutical Sciences. 2001;28:171-95.
18. Zhou H, Saliba J, Sandusky GE, Sears CR. XPC protects against smoking-and carcinogen-induced lung adenocarcinoma. Carcinogenesis. 2019 Mar;40(3):403-11.
19. D.M. Shlian, J. Goldstone. More on BHT toxicity. Western J. Med., 145 (5) (1986), p. 699
20. Argyris TS. Promotion of epidermal carcinogenesis by repeated damage to mouse skin. American journal of industrial medicine. 1985;8(4‐5):329-37. https://doi.org/10.1002/ajim.4700080412
21. Uray IP, Dmitrovsky E, Brown PH. Retinoids and rexinoids in cancer prevention: from laboratory to clinic. InSeminars in oncology 2016 Feb 1 (Vol. 43, No. 1, pp. 49-64). WB Saunders.
22. Ianhez M, Fleury Junior LF, Miot HA, Bagatin E. Retinoids for prevention and treatment of actinic keratosis. Anais brasileiros de dermatologia. 2013 Aug;88(4):585-93.
23. Sumita JM, Miot HA, Soares JL, Raminelli AC, Pereira SM, Ogawa MM, Picosse FR, Guadanhim LR, Enokihara MM, Leonardi GR, Bagatin E. Tretinoin (0.05% cream vs. 5% peel) for photoaging and field cancerization of the forearms: randomized, evaluator‐blinded, clinical trial. Journal of the European Academy of Dermatology and Venereology. 2018 Oct;32(10):1819-26.
24. Campuzano-García AE, Torres-Alvarez B, Hernández-Blanco D, Fuentes-Ahumada C, Cortés-García JD, Castanedo-Cázares JP. DNA Methyltransferases in Malar Melasma and Their Modification by Sunscreen in Combination with 4% Niacinamide, 0.05% Retinoic Acid, or Placebo. BioMed research international. 2019.
25. Moon RC, Mehta RG. Retinoid inhibition of experimental carcinogenesis. InChemistry and biology of synthetic retinoids 2018 Jan 18 (pp. 501-518). CRC Press.
26. Blume‐Peytavi U, Fowler J, Kemény L, Draelos Z, Cook‐Bolden F, Dirschka T, Eichenfield L, Graeber M, Ahmad F, Alió Saenz A, Rich P. Long‐term safety and efficacy of trifarotene 50 μg/g cream, a first‐in‐class RAR‐γ selective topical retinoid, in patients with moderate facial and truncal acne. Journal of the European Academy of Dermatology and Venereology. 2020 Jan;34(1):166-73.
27. Mukherjee S, Date A, Patravale V, Korting HC, Roeder A, Weindl G. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clinical interventions in aging. 2006 Dec;1(4):327.
28. Kang, S., Bergfeld, W., Gottlieb, A.B. et al. Long-Term Efficacy and Safety of Tretinoin Emollient Cream 0.05% in the Treatment of Photodamaged Facial Skin. Am J Clin Dermatol 6, 245–253 (2005). https://doi.org/10.2165/00128071-200506040-00005
29. Lucky AW, Cullen SI, Funicella T, Jarratt MT, Jones T, Reddick ME. Double-blind, vehicle-controlled, multicenter comparison of two 0.025% tretinoin creams in patients with acne vulgaris. Journal of the American Academy of Dermatology. 1998 Apr 1;38(4):S24-30.
30. Riahi RR, Bush AE, Cohen PR. Topical retinoids: therapeutic mechanisms in the treatment of photodamaged skin. American journal of clinical dermatology. 2016 Jun 1;17(3):265-76.
31. Antille C, Tran C, Sorg O, Saurat JH. Topical β‐carotene is converted to retinyl esters in human skin ex vivo and mouse skin in vivo. Experimental dermatology. 2004 Sep;13(9):558-61.
31. Wertz K, Seifert N, Hunziker PB, Riss G, Wyss A, Lankin C, Goralczyk R. β-carotene inhibits UVA-induced matrix metalloprotease 1 and 10 expression in keratinocytes by a singlet oxygen-dependent mechanism. Free Radical Biology and Medicine. 2004 Sep 1;37(5):654-70.
32. Darvin ME, Fluhr JW, Meinke MC, Zastrow L, Sterry W, Lademann J. Topical beta‐carotene protects against infra‐red‐light–induced free radicals. Experimental dermatology. 2011 Feb;20(2):125-9.
33. Lucky AW, Cullen SI, Funicella T, Jarratt MT, Jones T, Reddick ME. Double-blind, vehicle-controlled, multicenter comparison of two 0.025% tretinoin creams in patients with acne vulgaris. Journal of the American Academy of Dermatology. 1998 Apr 1;38(4):S24-30.
34. BHA: Class 2B on WHO Carcinogens List (IARC)
36. BHT and BHT-quinone, mouse carcinogens: S. Oikawa, K. Nishino, S. Oikawa, S. Inoue, T.Mizutani, S. Kawanishi. Oxidative DNA damage and apoptosis induced by metabolites of butylated hydroxytoluene. Biochem. Pharmacol., 56 (1998), pp. 361-370, 10.1016/S0006-2952(98)00037-9
37. Prop 65 Cancer Warning for BHA: https://oehha.ca.gov/chemicals/butylated-hydroxyanisole
38. Moch RW. Pathology of BHA-and BHT-induced lesions. Food and Chemical Toxicology. 1986 Oct 1;24(10-11):1167-9.
39. Imokawa G. Mechanism of UVB-induced wrinkling of the skin: paracrine cytokine linkage between keratinocytes and fibroblasts leading to the stimulation of elastase. InJournal of Investigative Dermatology Symposium Proceedings 2009 Aug 1 (Vol. 14, No. 1, pp. 36-43). Elsevier.
40. Fisher GJ, Datta SC, Talwar HS, Wang ZQ, Varani J, Kang S, Voorhees JJ. Molecular basis of sun-induced premature skin ageing and retinoid antagonism. Nature. 1996 Jan;379(6563):335-9. https://doi.org/10.1038/379335a0
41. Mekjavic IB, Macdonald IA. Melatonin-Induced Nocturnal Vasodilatation Contributes to Skin Regeneration. JAMA pediatrics. 2016 Jun 1;170(6):621-2.
42. Sherratt MJ, Hopkinson L, Naven M, Hibbert SA, Ozols M, Eckersley A, Newton VL, Bell M, Meng QJ. Circadian rhythms in skin and other elastic tissues. Matrix Biology. 2019 Aug 15.
43. Imokawa G, Ishida K. Biological mechanisms underlying the ultraviolet radiation-induced formation of skin wrinkling and sagging I: reduced skin elasticity, highly associated with enhanced dermal elastase activity, triggers wrinkling and sagging. International journal of molecular sciences. 2015 Apr;16(4):7753-75.
44. Rosenthal DS, Griffiths CE, Yuspa SH, Roop DR, Voorhees JJ. Acute or chronic topical retinoic acid treatment of human skin in vivo alters the expression of epidermal transglutaminase, loricrin, involucrin, filaggrin, and keratins 6 and 13 but not keratins 1, 10, and 14. Journal of investigative dermatology. 1992 Mar 1;98(3).
45. Zhu YK, Liu X, Ertl RF, Kohyama T, Wen FQ, Wang H, Spurzem JR, Romberger DJ, Rennard SI. Retinoic acid attenuates cytokine-driven fibroblast degradation of extracellular matrix in three-dimensional culture. American journal of respiratory cell and molecular biology. 2001 Nov 1;25(5):620-7.
46. De Lacharriére O, Escoffier C, Gracia AM, Teillac D, Saint Léger D, Berrebi C, Debure A, Lévêque JL, Kreis H, De Prost Y. Reversal effects of topical retinoic acid on the skin of kidney transplant recipients under systemic corticotherapy. Journal of investigative dermatology. 1990 Nov 1;95(5):516-22.
47. Fisher GJ, Datta S, Wang Z, et al. c-Jun-dependent inhibition of cutaneous procollagen transcription following ultraviolet irradiation is reversed by all-trans retinoic acid. J Clin Invest. 2000;106(5):663–70 (PMID 10974019).
48. Dhital B, Durlik P, Rathod P, Gul-E-Noor F, Wang Z, Sun C, Chang EJ, Itin B, Boutis GS. Ultraviolet radiation reduces desmosine cross-links in elastin. Biochemistry and biophysics reports. 2017 Jul 1;10:172-7.
49. Kang S, Fisher GJ, Voorhees JJ. Photoaging: pathogenesis, prevention, and treatment. Clin Geriatr Med. 2001;17(4):643–59, v– vi (PMID 1153542).
50. Lateef H, Stevens MJ, Varani J. All-trans-retinoic acid suppresses matrix metalloproteinase activity and increases collagen synthesis in diabetic human skin in organ culture. The American journal of pathology. 2004 Jul 1;165(1):167-74.
51. Sun M, Wang P, Sachs D, Xu Y, Xu Y, Voorhees JJ, Fisher GJ, Li Y. Topical Retinol Restores Type I Collagen Production in Photoaged Forearm Skin within Four Weeks. Cosmetics. 2016 Dec;3(4):35. https://doi.org/10.3390/cosmetics3040035
52. Dhital B, Durlik P, Rathod P, Gul-E-Noor F, Wang Z, Sun C, Chang EJ, Itin B, Boutis GS. Ultraviolet radiation reduces desmosine cross-links in elastin. Biochemistry and biophysics reports. 2017 Jul 1;10:172-7.
53. Kang S, Fisher GJ, Voorhees JJ. Photoaging: pathogenesis, prevention, and treatment. Clin Geriatr Med. 2001;17(4):643–59, v– vi. https://doi.org/10.1016/S0749-0690(05)70091-4
54. Lateef H, Stevens MJ, Varani J. All-trans-retinoic acid suppresses matrix metalloproteinase activity and increases collagen synthesis in diabetic human skin in organ culture. The American journal of pathology. 2004 Jul 1;165(1):167-74. https://doi.org/10.1016/S0002-9440(10)63285-3
55. Sun M, Wang P, Sachs D, Xu Y, Xu Y, Voorhees JJ, Fisher GJ, Li Y. Topical Retinol Restores Type I Collagen Production in Photoaged Forearm Skin within Four Weeks. Cosmetics. 2016 Dec;3(4):35. https://doi.org/10.3390/cosmetics3040035
Common questions about retinol:
Retinol has many skin benefits including the clinical improvement of fine wrinkles, stimulation of collagen, effectiveness in the treatment of aging and photoaging.
Retinol is not derived from plants. When we see retinol in skincare, or as a topical, it’s typically been lab synthesized with citral from lemongrass or beta-carotene.
I saw a difference in my skin in just 3 days with one of the African Botanics products and most recently it was practically a matter of minutes with Maya Chia’s Straight A. Full review here.