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Part 2 - Knowing your Retinols from your Retinoids - manufacturing, labelling and packaging

Updated: Jan 14, 2023

In this part I will cover the manufacturing, labelling and packaging of retinoids.


Choosing a Retinoid

A retinoid is defined as any molecule that binds and activates those beneficial anti-ageing retinoic acid receptors.

There are multiple Over-The-Counter (OTC) retinoid containing products to choose from. Picking the one that is right for you can be confusing.

And choosing one that really works can be trial and error.

When prices of non-prescription retinoids range from £5 up to £200, it would be nice to know.

There are a few tips you can follow and knowing that your OTC retinoid is manufactured properly, labelled clearly, and packaged correctly, will at least give you some reassurance that the retinoid is doing “what it says on the jar”.

Where is the scientific proof for that retinoid containing creams are anti-ageing?

Less than a handful of prescription retinoids are approved for anti-ageing, which means they have been studied in a well conducted clinical trial.

OTC retinoid-containing products do not need to be subject to clinical trials because they are being sold as “cosmetics” rather than drugs.

If retinol, for example, is listed as an inactive ingredient (or not at all), it does not need to be regulated as a drug. This clever loophole means that without a clinical trial which uses hundreds of people (and not a few personal reviews), you will never know whether they work.

Labelling retinoids 

Most companies rarely list retinoids as an active ingredient.

One particular retinol cream, advertised on the TV in 2022, lists hyaluronic acid as the only ingredient.

Another, from another leading skincare brand, lists dimethicone as the “active” ingredient. Dimethicone comes from silicone (silica based) and is used in many skin care products to make them easier to apply. 

Diemethicone is poorly absorbed and just sits on the skin, and by filling in cracks, it makes the skin feel smooth. To make things worse, the silica is then washed off causing harm to the environment.

Now look at the ingredient list in another, this time sold in an open jar.

Face Moisturiser: Aqua, Dimethicone, Glycerin, Tapioca Starch, Dimethicone Crosspolymer, Retinyl Propionate, Caprylic/Capric Triglyceride, Retinol, Palmitoyl Pentapeptide-4, BHT, Butylene Glycol, Dimethiconol, Niacinamide, Polysorbate 20, Laureth-4, Laureth-7, Disodium EDTA, Polyacrylamide, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Aminomethyl Propanol, PEG-100 Stearate, Ammonium Polyacrylate, Polymethylsilsesquioxane, Titanium Dioxide, C13-14 Alkane, DMDM Hydantoin, Iodopropynyl Butylcarbamate, Benzyl Alcohol, Methylparaben 

As you can see there is no indication of the strength of retinol, plus a retinyl ester and dimethicone are sneaked in.

For labelling and advertising purposes, it is true that it is a retinol “containing” cream. But how effective is it? Probably not.

In a recent study, when twenty-one commercially available retinol-containing skincare products were compared, over half of the products tested revealed differences in the retinoid amount claimed and what was actually in the product.

Be wary of customer reviews

Customer reviews of retinoid-containing cosmetics reporting their skin, lines and wrinkles improved after a week of use are probably laden with moisturisers (such as dimethicone above).

So you should be sceptical of what they say. Even prescription retinoids take up to 9 months of continued use to work.

Ingredients in Over The Counter (OTC) retinoids

Retinyl palmitate, a retinyl ester, is the most commonly used retinoid in cosmetic skin care products. It is also the least effective because it requires conversion to retinoic acid using two-steps rather than one.

Also this “conversion” is unlikely to happen as it will degrade almost instantly on contact with the skin.

These are some of the other retinoids found in OTC creams:

  • Retinol

  • Retinyl esters (see the next section)

  • Retinaldehyde (labelled as retinal)

  • Retinyl retinoate

  • Retinyl N-formyl aspartamate 

Retinaldehyde, best known as as retinal, only requires one step to retinoic acid and as a result, is the strongest OTC retinoid you can buy without a prescription (apart from Adapalene, which is only indicated if you suffer with acne).

β-carotene is also found in many retinoid skin creams. β-carotene is not strictly a retinoid, but is converted into retinol. It belongs to the carotenoid family and is a provitamin found in plants.

The Many Retinyl Esters

Retinyl esters have many (dis) guises:

  • Retinyl propionate

  • Retinyl palmitate

  • Retinyl acetate

  • Retinyl stearate

  • Retinyl linoleate

  • Retinyl oleate

Retinyl esters are:

  • The weakest of the retinoid class.

  • The least irritating.

  • The most stable.

As they are non-irritating, this is why skincare brands prefer retinyl esters in their retinoid formulations.

Retinyl esters are large molecules that require a three-step conversion to become retinoic acid. It is doubtful however that this is happening at all.

Retinyl esters also do not penetrate the skin very well. So beware.

Retinoids and skin flaking

One of the main ways to know your retinoid is working is they cause skin flaking. Skin flaking is a sign of new skin cell production as old skin cells are replaced underneath.

Although this can be troublesome at first, for most people it does settle down albeit in a week or two.

So, as a final word of caution, if the product you buy is labelled as non-irritating, and you do not flake, it probably means it does not work.

Strength of retinoids

OTC retinoids are 20 times weaker than retinoic acid as they require conversion to become active. The more steps needed, the less strong or potent they are. This is their Achilles Heel.

As a reminder:

As a rule, the less strong the retinoid, the less skin irritation you get. As a result, these weaker retinoids are the most popular ingredients used by OTC or commercial manufacturers.

Manufacturers know that you are more likely to continue using the cream, especially if they are not too strong.

What about Adapalene?

Adapalene can now be bought OTC. This is great news for acne sufferers, as before 2016 Adapalene required a prescription.

The approval of OTC adapalene followed a study which showed that people could sensibly decide whether adapalene was right for them, be able to understand the information on the label, and then use the adapalene correctly.

Retinol instability

Retinol is very unstable and degrades in seconds when it is exposed to:

  • Heat.

  • Light.

  • Air.

  • Water.

  • Changes in acidity or pH such as found on the skin.

Retinol that has reacted is ineffective and is the reason why formulations containing retinol should be made using strict manufacturing processes that never expose the retinol to light or air.

This is also the reason that retinols should not be packaged in jars or transparent bottles.

Shelf life of retinoids

Most retinol products only last 3-6 months once opened and what's worse if they are not manufactured correctly, they will have degraded even before opening.

Factors affecting retinoid efficacy 

The following factors summarise why your retinoid might not be working:

  • It is one of the weaker retinoids

  • The product is not pure with additives to make it last longer or make it easier to apply 

  • Too low a percentage

  • Air or light exposure during mixing

  • Air or light exposure during transfer into the pump or tube packaging

  • Air or light exposure once opened

How retinols should be manufactured

Retinols should be manufactured carefully in the following way:

  • Subject to less than 40°C during processing. 20°C is best.

  • Made in an alkaline environment (pH 5.5-8.) rather than exposed to acid.

  • Stored in aluminium lined tubes which are protected from oxygen.

Many cosmetic skincare products containing retinol are not manufactured or stored in this way, making it likely that the retinol in these products has very little, if any, effect when applied to the skin. 

How retinols should be packaged

Retinols should be sold in airless pump devices. 

Reports that they remain stable for up to two years are dubious.

What % retinol?

Most commercial retinoid products are made with 0.04%-1% retinol.

Most retinols are not interchangeable, so that the same percentage creams (for instance 0.1%), from different brands, are unlikely to have the same effect or potency.

As a rule, the higher the % of retinol, the more effective it becomes, but this runs the risk of more irritation. It is recommended that you should not use retinol over 1%.

Encapsulated Retinoids

To get around the instability of retinoids, they are often encased or “encapsulated” in a protective shell such as an oil or fatty molecules (called a liposome). 

Encapsulated retinoids might give you some comfort that it is more stable than one that isn’t.

The Advantages of encapsulated retinoids

  • The retinoid is protected and less likely to get broken down.

  • The product may penetrate the skin better.

  • They release retinoid much slower which causes less skin redness and irritation.

The downside to encapsulated retinoids

Encapsulated retinols tend to be more expensive. Also, more often than not, there is often very little retinol inside, so you may not get very much retinol into your skin.

In addition the shells need to break open. This happens naturally or when you rub the product in the correct way on your skin.

Take home messages

  1. OTC retinoids are safe but many probably don’t work.

  2. From a manufacturers point of view, adding “retinol” to a label or name makes the product sell, even if the amount and the way it is made is unclear.

  3. There is very little evidence available to support the use of over-the-counter cosmetic retinol-containing products to improve the appearance of aged skin.

  4. Retinyl esters and Retinol remain a popular ingredient as they have low irritation levels making them more tolerable and safe to use.

If lack of irritation is your main deciding factor to continue using your preferred retinoid product, and if it works (and doesn’t just moisturise) that's fine.

Otherwise buy a reputable retinol or retinoid directly from our clinic. We have a number of great ones in stock. And all our chosen retinoids are manufactured under strict quality control.


Temova Rakuša, Ž, Škufca, P, Kristl, A, Roškar, R. Quality control of retinoids in commercial cosmetic products. J Cosmet Dermatol. 2021; 20: 1166– 1175.

Against retinol

Their conclusion “Until at least one high-quality clinical trial of retinol-containing products in the treatment of (photo-)aged skin is published, there is very little, if any, trustworthy evidence available to support the use of over-the-counter cosmetic retinol-containing products to improve the appearance of aged skin”.

For retinol

An opposite view.

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