Everything you need to know about retinoids

Everything you need to know about retinoids

Everything you need to know about retinoids

Confused by the abundance of different retinoid products out there? Read on to get Gary’s take.

Did you know all retinoids are forms of vitamin A? Time to learn what this powerhouse skincare ingredient can do for your skin!

Retinoid, retinol, retinoic acid – the cosmetics industry has practically invented a sport of throwing these terms around. Used interchangeably in slick ads and scrawled across fetching packaging, it’s understandable if you were under the impression that all retinoids were created equal – and honestly, the cosmetics industry has put a lot of effort and money into keeping it that way. 

But are all vitamin A products created the same? Do you really understand how these mythical anti-aging powerhouses work? Read on to find out!


There’s good reason to be enamoured with retinoids 

There’s nothing I love more than a skincare ingredient that stands up to peer-reviewed research (and the test of time), and retinoids check that box. Not only are retinoids one of the most Googled skincare ingredients on the planet, they’re also one of the most researched and studied skincare ingredients in our arsenal. 

Why do I love peer-reviewed research so much? When research is peer-reviewed, it means multiple researchers from different, independent labs (not to be confused with cosmetic company labs) ‘test’ the assumptions and results other independent researchers have made. They aren’t trying to prove something works when they check each other’s work, they’re goal is to prove everyone’s assumptions are wrong. So, when a skincare ingredient, like retinoids, stands up to the test of peer reviewed research, it means they really can do something for the skin. 

From all that research, we know that retinoids have a profound effect on not just how the skin looks but more importantly how the cells that make up different layers of your skin behave. They do this by changing the way genes in skin cells are expressed (making retinoids a hormone). In a lot of ways, retinoids can turn back the cellular clock, encouraging skin cells to act like their younger and healthier counterparts. From acne to aging and repairing sun-damaged skin, there’s a LOT retinoids can do to improve things. 

So why are there so many different retinoids available and which one is for you?

A retinoid is a retinoid is a retinoid? With all the different retinoid products out there, the choice can be overwhelming. Which retinoid is your anti-aging powerhouse?

Retinoid isn’t a single ingredient, it’s a term used to describe all vitamin A derivatives. Think of it like a family name. Retinol, retinoic acid, retinaldehyde (retinal), and adapalene – types of retinoids you may be familiar with – are all members of the retinoid family. And, like all families, they each have their own quirks and talents. 

Retinoic Acid: The big fish in the retinoid pool

The ‘biggest hitter’ in the retinoid family is retinoic acid, and that’s because it’s the active form of the hormone. 

When retinoic acid enters a skin cell, it activates a special protein called the Retinoic Acid Receptor (RAR). Once activated, the RAR finds and binds to a special sequence of your DNA called the Retinoic Acid Response Elements (RARE). The result? Genes are turned on in 3 specific categories: 

  • Genes that increase cell turnover of the keratinocytes in the epidermis smoother, brighter, more even skin.  
  • Genes that kick fibroblast cells into high gear, making more elastin, hyaluronic acid, and collagen. This leads to plumper, thicker skin.
  • Genes that improve pigmentation and melanin distribution greatly improving sun damage. 

Because retinoic acid is ‘the active hormone’, it doesn’t need any processing or enzymatic activation – as soon as it’s applied to skin, it starts working. That makes it the most potent of the retinoids and why it’s a prescription product. It’s also the one which you’ll see the fastest and strongest results with. 

With strength however there often comes a cost, and retinoic acid is no different. Well known side effects of retinoic acid include dry, flaky, irritated skin – and that’s where the rest of the family comes in.

Retinol and its siblings: the sensitive ones

If you struggle with sensitive skin and have difficulty tolerating prescription retinoic acid, retinol (or one of its siblings) might be for you.

Like retinoic acid, retinol and retinal also increase cell turnover and collagen production, but they are not interchangeable products, and you shouldn’t treat them as such (as much as cosmetics companies confuse the issue and try to convince you otherwise). If retinoic acid is the ‘big fish in the pond’, think of retinol and retinal as the kids. They have the potential to become the active hormone, but there’s room to grow. 

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Retinol is the precursor to retinoic acid. It’s oxidized reversibly (meaning it can go back and forth) to retinaldehyde (retinal) by the enzyme retinol dehydrogenase (1), after retinol binds to cellular retinol binding protein type-1 (CRBP1). Retinaldehyde (retinal) is then irreversibly converted to retinoic acid (the active hormone) by retinaldehyde oxidase

Retinol and retinal to retinoic acid. It takes time, oxidation, enzymes, and accessory proteins. To get retinoic acid out of retinol. Retinol is a precursor to retinoic acid. It’s oxidized reversibly to retinaldehyde (retinal) by the enzyme retinol dehydrogenase after retinol binds to cellular retinol binding protein type-1 (CRBP1). This reaction is reversible. Retinaldehyde (retinal) is irreversibly converted to retinoic acid by retinaldehyde oxidase.


Rohinmishra, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons


What this means is that the steps to turn retinol and retinal into retinoic acid are limiting (for more discussion on the cellular processes, check out my video on retinoids here). Even when retinol is used in high concentrations, it takes a lot of time, energy, and effort for a cell to get retinoic acid out of it. And not all the retinol in a product will be converted to retinoic acid (remember that reversible limiting step?). Enzymes just don’t work like that. 

This lower potency makes retinol (and retinal) gentler options for skin while delivering on many of the same benefits as a prescription retinoic acid. The caveat is that it takes longer to see results with retinol and the results won’t be as impressive. But depending on what you want out of a retinoid, the gentler formula might outweigh that. 


Which retinoid is best for me?

It really depends on the results you want to see and your skin. For example, moderate acne users and people treating significant sun damage may want to go straight to a prescription product, but someone with mild acne, few wrinkles, who is seeing the first signs of sun damage might find that retinol delivers great results without the irritation. 

Many people can’t tolerate prescription retinoic acid, and retinol is a viable option to still reap the benefits. For some people, not having to get a prescription is also a huge plus. Retinol can also be a great starting point to work up to a prescription product. And you really don’t need to spend a lot to get a great retinoid. There are many affordable retinol products available in your local pharmacy and online (I mention a few in the video), as well as generic prescription products. 

What it comes down to is experimentation, the results you want, and your skin. And now you can hit the aisle armed with a well-rounded understanding of how retinoids work! 

Retinoid Reality Checklist 

  • Don’t overdo it. Retinoids are active ingredients. Too much too soon won’t get you results sooner, and really increase your risk of irritation. Start slow and at low concentrations. Work up to every night. Retinoids can be just as effective when applied every other day, especially when you’re starting out. 
  • More isn’t better. Retinoid products recommend you apply a pea sized amount. More will only waste the product and increase the risk of irritation. 
  • Apply at night. Many retinoid products are unstable in the sun. 
  • Be careful mixing with other active ingredients. Benzoyl peroxide, acids, vitamin C, and other medications can increase irritation.
  • Moisturizer could be your friend. If you’re having difficulty getting your skin used to a retinoid, try mixing it with a gentle moisturizer when you apply to dilute the product (we’re launching our own moisturizer soon). 
  • Be patient and consistent. It can take 6 weeks to see results. 
  • Don’t use retinoids during pregnancy
  • Discontinue retinoids 3-7 days before lasers and energy devices. Otherwise, it could lead to complications. 
  • Sun protection. Yes, I’m sounding like a broken record, but whether you use prescription strength retinoic acid or an over-the-counter retinol, you need to wear sunscreen. Retinoids increase sun sensitivity – a lot.

Do you use retinol or retinoic acid? Which do you prefer? Let us know what other skincare ingredients you’d like us to review! 


Written by
Kristi Charish
Edited by
Dr. Gary Linkov
The content of this newsletter is for entertainment and educational purposes only. This content is not meant to provide any medical advice or treat any medical conditions. Patients must be evaluated by an appropriate healthcare provider on an individual basis and treatment must be tailored to meet that patient’s needs. Results and particular outcomes are not guaranteed.


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