Everything You Need to Know About Retinol: Part 2
In the first article of our two part retinol series, we established some of the basics on the science of retinoids, its history, and its unique ability to alter the structure of our skin. Now that we’ve set the context for retinol, we’re diving into regulations and safety, how chemists approach retinol-based formulation, and most importantly, why all retinol products are not created equal. We will also go a step further and review some products on the market that are likely worth the investment. So stick around! It’s gonna be worth it.
First, more on the origins of retinoids
Vitamin A (retinol) is an essential vitamin involved in the daily functioning of human beings (i.e. vision, reproduction, immune function) that also helps regulate cellular growth and differentiation within the epidermis. You might be familiar with a carotenoid called beta carotene — a red/orange pigment found in many fruits and vegetables we consume on a daily basis. This plant pigment converts to vitamin A in the body and becomes an essential vitamin.
While vitamin A and its derivatives can be found in nature, and even animals, it’s impossible to get a stable, bioavailable retinoid from nature for cosmetic application. Retinol and its derivatives in cosmetics are mostly synthetic. This qualifies them as vegan if no animal based ingredients are used during processing. Knowing this simple truth, you can ignore skincare products with vegan retinol claims that are marketed as better clean beauty products, which is highly misleading.
Moving on to safety and regulations
Retinol’s prowess as an anti-ager is undeniable, but we have to acknowledge some of the gnarly side effects that can come with using this tried and true ingredient. Due to the skin irritation and erythema (redness) observed with retinoid use (which can manifest as dry, itchy or flaky skin) as well as increased photosensitivity, sunscreen and a good moisturizer are your biggest allies.
When it comes to regulation, the story gets a bit tricky because we’re talking about something we receive both from ingesting food and topically from our skincare products. If Vitamin A is consumed in excess amounts (which includes cutaneous absorption via topical products), it can be toxic. Studies have shown that an excess of Vitamin A has the potential to affect embryonic development and result in something known as teratogenesis — the production of birth defects in a growing embryo. That is why it is recommended women stop using topical retinoid products when pregnant or nursing as the risk outweighs the benefits.
When identifying safety parameters and a threshold for retinoid use, there are two main governing bodies we look to for support as chemists, brands, and manufacturers:
The Proposition 65 list of California that outlines the safety of retinol and retinyl esters in cosmetic products, and falls under a category called developmental toxicity. Retinol and its esters are considered safe in daily dosages below 10,000 IU, or 3,000 retinol equivalents. Having said that, retinol/retinyl esters are required and essential for maintenance of normal reproductive function are recommended daily at a level of 8,000 IU during pregnancy.
The Scientific Committee on Consumer Safety (SCCS), where the threshold is lower in terms of maximum usage level of retinol and its esters in cosmetic products: 5,000 IU vs Prop 65’s 10,000 IU. If a brand wants their products to be globally compliant, they will follow the SCCS in terms of regulation and safety. The bigger brands (think, Unilever and P&G) follow SCCS standards.
As per SCCS, a maximum concentration of .05% for body lotions and a maximum concentration of 0.3% for leave-on hand/face creams and rinse-off products are considered safe for retinol and retinyl esters such as retinyl acetate and retinyl palmitate.
Because retinol is a vitamin that we get daily through consuming food, safety parameters are traditionally demarcated in IU (which stands for “international unit” and is a “internationally accepted amount of a substance”). You probably recognize this type of measure from a supplement facts label, which is used for fat-soluble vitamins (e.g. vitamins A, D and E) and certain hormones, enzymes, and biologicals (e.g. vaccines).
If you’re wondering about products that feature retinol at percentages far exceeding recommended levels (e.g. 1-2%), those brands are trying to play the ‘higher numbers’ game, where percentages may be attributed to a complex of ingredients such as stabilizers, carriers, or booster ingredients, and not just retinoids (e.g. Boots #7 Advanced Retinol 1.5% Complex). Also, usage of a higher percentage can be accommodated if the company has data to support that their product — when used under ideal usage guidelines — does not exceed the maximum IU in skin absorption.
Oh, and one more thing. Any cosmetic formulator will consider the thresholds outlined by Proposition 65 or the SCCS and arrive at an acceptable percentage for a particular formula based on the ingredient spec provided by the raw material supplier. It’s just a matter of unit conversions given that ingestible and topical are different product types.
When retinol is in the picture, there is a fine line between cosmetics and drugs
Before we move on from the regulatory side of things, we gotta cover one last point. When it comes to retinol, the lines have blurred between what we consider a drug and what we consider a cosmetic, and you can probably guess why. Brands are all making similar anti-aging claims. Remember, a drug is a product intended to affect the structure or function of the body (e.g. the skin) while a cosmetic is something that beautifies and enhances your appearance. When we use words like “increases collagen production,” we’re technically making a drug claim for a product marketed as a cosmetic. And because the FDA does not approve cosmetics before they go on the market, there are a lot of loopholes.
Prescription retinoid products such as Tretinoin (Retin-A), Tazarotene (Tazorac), Adapalene (Differin), and Isotretinoin (Accutane), on the other hand, go through years of research during the drug approval process, which includes extended testing to support the approved claim while establishing data of bioavailability, systemic absorption and any side effects. There is also another category of products available through doctor’s prescription via compounded pharmacies where pharmacists are allowed to blend non-approved drug combinations and dispense to patients without undergoing the rigors of a new drug application process (e.g. Curology or Apostrophe).
Not all Retinol products are created equal
It’s a matter of stability. Aside from sunscreens, it’s safe to say that creating stable and efficacious retinol-based formulas is the most complex; it is bound to test the skills of even the most experienced cosmetic chemist. One of the main reasons for this is that retinol and its derivatives are highly unstable...to water, light, air...you name it. And to be able to preserve its integrity through formulation design and the entire development and manufacturing/filling process is no easy feat.
We can say with confidence that the majority of retinol products on the market are not stable, with some exceptions from reputed companies that have developed a system to maintain the integrity of retinol or are able to preserve it from degradation for longer periods of time.
Let’s say a company puts 0.05% retinol in a formula. Once it reaches the hands of the consumer, it may have already started to degrade, or will over time once the package is opened. The strength of retinol is also inconsistent across most products. Some companies claim it on the label, while some don’t. And some products feature higher percentages while some are just sprinkled in for the story.
Last but not least, we can’t forget to mention that choosing the right packaging is key in developing this type of product and preserving formula stability. The beauty is that there is a lot of new innovation to keep retinol fresh, for longer: capsules, airless droppers and pumps, and even packs with two chamber compartments where retinol is freshly released. The best option is arguably aluminum (which also ticks the boxes for sustainability), though, because it blocks light and is impervious to air.
The retinol (vitamin A) family is extensive...with more members than the Baldwin’s — but each derivative has its own unique characteristics and degrees of efficacy (remember, path to conversion in becoming retinoic acid varies) that have to be taken into account when formulating.
Higher strengths doesn’t mean better. Retinol started at low levels back in the day, then evolved into patented versions, and now brands are competing on numbers. But a higher percentage retinol product is not necessarily more effective. Nuance is everything in formulation; it all depends on the overall design and how ingredients come together to create the perfect synergy.
What’s the vehicle? Skincare delivery systems used to be a popular topic of conversation back when liposome technology was all the rage. Since liposomes we moved on to various encapsulation techniques, and today we have next generation encapsulation technologies like “microsponge” or “polypore.” These systems entrap retinol in an inert powder; it’s essentially absorbed into it. Dontcha just love science?! But regardless of the delivery system, retinol will penetrate the skin — that’s just the nature of the beast.
Format. Oil-in-water emulsions (a.k.a. creams or lotions) are the most common formats for retinol products with serums a close second. Anhydrous systems like oils, silicone bases, or wax-based formats (e.g. Peace Out Retinol Eye Stick) are mainly used to avoid exposure of retinol to water, and to some extent, air.
So, when a chemist approaches the bench to formulate, it all boils down to the following:
The type of retinoid used and its inherent stability
% of retinoid used
Stability of the formula (which includes delivery system)
The necessity to avoid light & air during the entire formulation and manufacturing/filling process
Employing a type of packaging where the formula is exposed to minimal amount of air and light as possible
The simplicity of the formula: the more ingredients, the greater the potential for retinol to interact with other active ingredients and get destabilized
Other ingredients in the formula that enhance stability of the retinol, like antioxidants or ingredients that reduce the water activity of the formula
Additional ingredients that may enhance performance of the product such as niacinamide, peptides, botanicals, humectants and skin penetrants
Drumroll, please...here are our top picks for retinol products
Even as cosmetic experts we’re not able to tell you with 100% certainty what the best retinol products are on the market, but we can tell you what is most likely to work better than others. The thing is, we don't know how stable products are (we didn’t make them), what the percentage of retinoids or other supporting ingredients are, and what clinical studies were done (if at all). Usually, studies are not published or if they are, brands will cherry pick what they want to show to support product claims.
We’re all for reputable brands that have credible history and a track record for supporting products with decades of clinical data and patents to boot. Neutrogena, RoC and L’Oreal feature simplistic formulations, patented technologies and claims based on clinical testing. The below three products using pure retinol are likely not to disappoint, and they represent a choice between anhydrous oil, moisturizer and serum:
Neutrogena Rapid Wrinkle Repair .3% Retinol Oil ($34.99 / 30ml)
RoC Retinol Correxion Deep Wrinkle Night Cream ($24.99 / 30ml)
Loreal Night Serum .3% Retinol Serum ($36.99 / 30ml)
We also love modern brands that employ next generation retinoids and delivery systems. Again, below we have an anhydrous formula, moisturizer, and a serum to choose from:
Rodan & Fields Redefine Intensive Anti-Aging Serum ($102 / 60 capsules) features single use capsules with Retinaldehyde in a patented encapsulation system called hydroxysomes, which is unique to this direct-selling, beauty behemoth. In case you’re curious, hydroxysomes are calcium phosphate particles co-engineered with retinaldehyde, which facilitates enhanced absorption and recognition by the skin.
Olay Regenerist Retinol 24Max Night Face Moisturizer ($32.98 / 50.28 ml) focuses on providing 24 hour hydration and features niacinamide, peptides and a retinoid blend that primarily utilizes retinyl propionate (which is an ester) and retinol. With the blend, product stability, performance, and potential irritation is nicely balanced.
The Ordinary’s Granactive Retinoid 2% Emulsion ($9.80 / 30ml) features both pure retinol and granactive retinoid. The latter is a term used interchangeably with hydroxypinacolone retinoate (HPR), which is a form of retinoic acid ester (we covered this in Part 1). Technically speaking, granactive retinoid is a complex that features HPR and dimethyl isosorbide (a solvent) together. Hydroxypinacolone retinoate is unique because it binds directly to retinoid receptors, just like retinoic acid, but is much less irritating. (Btw, when you see a percentage of granactive retinoid, always divide by 10 to get the actual strength of HPR ☺)
Conclusion
If you’ve made it to the end here, congratulations! There was a lot to unpack, but we hope it’s been worthwhile. Now that you’re more educated on all things retinol, we hope you’re that much closer to making the best decision when it comes to your personal skin goals.
Curious about the future of retinol? Well, we can give you a quick synopsis. We’re anticipating that brands will continue to play the numbers game with higher percentages (versus recommended), stability involving product development/formulation will remain a key focus, innovation will be around new derivatives such as retinyl retinoate, and developers will look to create retinol from biotechnology/biofermentation processes that will appease clean beauty fanatics. And we wouldn’t be surprised if cannabinoids and retinol made more appearances together to ride the CBD wave.
Cover photo: Photo by Mathilde Langevin on Unsplash