The Evolution of Retinol: How to Tell Retinol, Retinoid, and Retinal Apart

Research Blog Written by Sunny Li

Retinol, one of the most versatile super ingredients, has been a fan favorite since forever. From being anti-aging, an enemy to acne and much more, who can resist the wonders of retinol.

However, shopping for one isn’t so simple. 

Under the aisles of countless retinols, retinoids and even something called bakuchiol, it feels like a head spinning high school chemistry class all over again. What even are these? Don’t they all do the same thing? Don’t worry, the AROOM team will answer all your questions and make this retinol journey feel like a breeze!

Retinol wasn’t always used for skincare. We need to know that retinoid is derived from vitamin A, and retinol is derived from retinoid. Hence, this makes retinoid an umbrella term for the derivatives. Initially, the discovery of vitamin A was used for the purpose of creating a healthy diet for humans. Now we know that vitamin A is crucial for growth, vision, and immunity. 

Scientist Nicolai Lunin conducted an experiment on rats to understand the importance of vitamin A by giving them a diet incorporating milk. Milk contains the vital vitamin A. The results show that the rats have grown in size and vitamin A is indeed an essential nutrient for our body. It wasn’t until World War I when people realized the importance of retinol for their skin. Having a deficiency of vitamin A can lead to xerosis (dry skin) and follicular hyperkeratosis (formation of thick skin that leads to bumpy patches on skin). 

Then in the 1940s, many business owners flocked to join the vitamin A industry due to the appealing benefits for the human body, especially retinol being anti-aging. Many participated in the vitamins, pharmacology and cosmetics industries. In the 1970s, the first retinoid called tretinoin was FDA approved. This revolutionary discovery paved its way through the skincare industry and has become one of the most popular forms of ingredients now. 

Before you head into your nearest skincare shop, let's stop and have a quick chat about retinol and their sisters. Retinoid, retinol, and retinal. They sound the same, right? You might think to yourself, “these three probably do the same thing.” WRONG.

Understanding the difference can really level up your skincare game.

Here’s how:

Retinoids, retinol and retinal all have one key difference that makes them unique. It's how they form into their active form, known as retinoic acid. So why is it important for them to turn into retinoic acid? Retinoic acid is able to bind with retinoic acid receptors (RAR) and Retinoid X Receptors (RXR) due to structural compatibility. These two receptors typically come in a pair called heterodimers. 

RARs have three different forms known as RAR-α, RAR-β, and RAR-γ. RXRs also have different forms known as RXR-α, RXR-β and RAR-γ. Our skin mostly has RAR-γ and RXR-α receptors. Retinoids are already in their most active form and readily bind with the receptors, making retinoids the strongest out of retinal and retinol. Retinol is a derivative of retinoids that is less potent, and requires two steps to convert to retinoic acid. This makes the retinol weakest of the three. Retinal, or retinaldehyde is a derivative form of retinol that is one step away from becoming retinoic acid. Retinal is essentially the intermediate step before retinol becomes retinoic acid.

Here's a comparison chart to understand the difference between them:

Category	Retinoid	Retinol	Retinal (Retinaldehyde)
General Facts	Retinoid is an umbrella term to categorize all derivatives under it. Popular retinoids include tretinoin and adapalene.	Retinol is a derivative of retinoid and requires two steps to convert to retinoic acid. It is naturally occurring in food and the human body.	Retinal is a derivative form of retinol and is an intermediate step before retinol becomes retinoic acid.
How it works	Retinoids readily bind with RAR-γ and RXR-α receptors, and help accelerate keratinization, produce new skin cells and promote epidermis production.	Retinol is fat soluble and is able to penetrate into the stratum corneum, then the dermis. Retinol helps with collagen production, and minimize skin hyperpigmentation.	Retinol dehydrogenase (RDH) or alcohol dehydrogenase (ADH) allows retinol to oxidize into the retinal by catalyzing this step. This means that retinal may work faster, but due to it being very unstable, it can  be less effective than retinol.
Potency	Very STRONG	Weak	Stronger than retinol (but might not absorb into skin well!)
Available In	Over the counter, prescription, creams, pills	Over the counter, spot treatments, eye cream, serums	Serums, creams, gel moisturizers, treatments
Targets	Loss of collagen, hyperpigmentation,	Hyperpigmentation, exfoliation, clogged pores, water loss	Acne, hyperpigmentation, photoaging, wrinkles, fine lines
Side Effects	Irritation, dryness, peeling skin, skin sensitivity	Irritation, dryness, peeling skin, itchiness, skin sensitivity	Irritation, dryness, peeling skin, itchiness, skin sensitivity

What if I told you there was actually an even better and gentle alternative for retinoids? Retinoids can do wonders for our skin, but it's not for everyone. People with acne prone skin or sensitive skin can suffer serious consequences to their skin. 

This is where bakuchiol comes to the rescue! 

Unlike retinoids, retinols, and retinals, bakuchiol has no relations to A and is plant based, as well as irritation free. A scientific study was conducted where one group used bakuchiol twice daily while another group used retinol twice daily. The results yielded that both groups had significant improvement of wrinkles and hyperpigmentation, but only the retinol group showed side effects of stinging and face scaling. Bakuchiol is quickly making a promising reputation and moving its way through the skincare industry5

AROOM is currently developing an eye cream incorporating bakuchiol.

Designed to deliver the benefits of retinol with a much gentler touch, this eye cream targets signs of aging without the irritation commonly associated with retinoids. We investigated ingredients that complement bakuchiol and came up with the following pairs:

1. Bakuchiol + Glutathione: Anti-oxidant power couple

• Both are strong antioxidants. Together, they could enhance the skin’s barrier against oxidative and external damage, resulting in strong anti-aging synergies.
• Skin brightening effects are also enhanced when combined. Bakuchiol helps fade hyperpigmentation and even skin tone through gentle cell turnover. Glutathione inhibits melanin production by restricting tyrosinase activity. 

2. Bakuchiol + Peptides: Skin elasticity enhancer 

• Peptides support collagen production and skin elasticity, and when combined with bakuchiol, the skin firming effects could be amplified.
• Both are also mild ingredients that cause little to no irritation, making it suitable for sensitive skin.

Our bakuchiol eye cream is still in development. If you have any thoughts or inputs, please let us know anytime by emailing us or reaching out to us elsewhere!

We believe in skincare as a ritual of relief, but most importantly, in skincare that works for you.

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