What are retinoids and what do they do?
There are few cosmetic ingredients that attract as much interest as retinoids and rightly so! Retinoids are derivatives of Vitamin A – they are one of the most clinically tested active ingredients in dermatology and are often touted as the ‘gold standard’ treatment of several skin concerns including acne, ageing, pigmentation, psoriasis and ageing. Vitamin A helps skin cells differentiate effectively which ensures a structurally resilient epidermis. They not only aid in collagen production but also slow the natural breakdown of collagen in the dermis by inhibitinging MMP’s (matrix metaloproteases; proteins that continually degrade our collagen)
Retinoids also support skin immunity by up-regulating antimicrobial peptides; signalling molecules that communicate with the immune system.
What is the difference between the versions of Vitamin A?
There are many forms of vitamin A so you won’t see “Vitamin A” on an ingredient list. Below you will find the different names of retinoids in order of strength from weakest to strongest:
Retinyl esters/acids (e.g.Retinyl Palmitate) – this is a storage form of Vitamin A so can accumulate in the skin and be converted when needed – gentle / recommended for sensitive skin.
Retinol – Themost common over the counter form of Vitamin A. Was until recently allowed in percentages of up to 1%. This has now been reduced to 0.3% in facial skin care.
Retinaldehyde (retinal) – strongest form of Vitamin A available in over the couneter products.
Retinoic Acid – prescription strength; tretion, isotretionoin, adapalene. – in my opinion this form should never be used in everyday skin care.
Only Retinoic Acid can be actively used by the cells so whichever version of retinoid you apply to the skin it will ultimately be converted into Retinoic acid.
Retinoids in skin products are converted via enzymatic processes in the following way:
Retinyl Esters
(The form of Vitmain A that is stored in skin & liver)
Converted to:
Retinol
Converted to:
Retinaldehyde
Converted to:
Retinoic Acid
(only Retinoic acid can penetrate into the nucleus of the cell to activate a response)
What percentage should I be using?
This is where it gets really confusing!
You can only use percentages to compare the same type of retinoid – for example 0.1% Retinoid Acid – is more potent than 1% retinol so you can’t compare these to each other
Prescription tretinoin (a from of Retinoic acid) is considered to be at least 20 x more potent than the highest OTC retinol and retinaldehyde is deemed to be 10 x stronger than retinol.
Vitamin A & delivery into the skin.
We often forget that the skin is designed to keep things OUT so getting any desirable ingredients INTO the skin is always a key question as it ultimately affects the efficacy of any product. Some companies use a process called encapsulation to ‘wrap’ the vitamin A in a microscopic lipid bubble. As we know the skin surface uses lipids as a form of protection so these capsules can assimilate into the skin barrier, reducing contact with the outside of the skin, minimising irritation and delivering it to the lower layers where it is released. Because there is no wastage at the surface this allows lower doses of vitamin A to still achieve the same result.
Can I use Vitamin A if I have sensitive skin?
Vitamin A is a highly active ingredient and depending on the strength, can be one of the most irritating. When used incorrectly or at a high potency it can lead to what is termed “retinoid dermatitis” characterised by redness, skin peeling and sensitisation. Each skin type has its own Vitamin A tolerance and sensitive skin often has a very low threshold. This is because the skin barrier is weak and inflammatory mediators are already heightened within sensitive skin, making it more responsive to “active ingredients”.
Even people who have no history of sensitivity can find their skin showing signs of stress when using potent versions of Vitamin A, so when working with a sensitive skin I would recommend the following:
- Use the gentlest versions (retinyl esters e.g. Retinyl Palmitate)
- Use it alternate days to begin with
- Mix it with your moisturiser or apply moisturiser first to act as a buffer
- Wear an SPF on days you will be outside for more than a few hours if using a vitamin A regularly
- Use Bakuchiol as an alternative (see blog on Bakuchiol)
What’s the controversy over Retinoids?
There is huge debate about Vitamin A and its potential negative side effects but as with most things this is all about the DOSE. Even when used in its most gentle form – Retinyl Palmitate, you will still build up a store of Vitamin A within the skin which is available whenever it is needed by the cells. Ultimately, all versions of Vitamin A are turned into Retinoic Acid within the skin and utilised in the same way. As with many things in skin care the approach always seems to be “the stronger the better” but most of the time this is absolutely not the case.
In recent years, prescription strength retinoids have become widely distributed online by remote consultation companies (who also encourage subscriptions to keep you on it for long periods) and I have seen repeatedly in my clinic the detrimental effect this can have on clients skin; peri-oral dermatitis, thin looking skin, patches of dermatitis and sometimes skin looks waxy or feels very dry. Prescription strength in my opinion is too much of a good thing which leads to poorer quality skin and sub-clinical inflammation.
Knowing what strength or percentage to use is difficult for the consumer but here are a few things to remember:
- Retinoid use should take a low and slow approach. The stronger the Vitamin A, the more chance you have of developing irritations, either in the short term or the long term so keep to a dose that yields results but doesn’t illicit any kind of negative impact.
- Encapsulated vitamin A will penetrate the skin more easily and allows for lower doses/higher efficacy.
- Vitamin A is just ONE thing in the MANY, MANY things that influence skin health so don’t get too preoccupied with it.
- Vitamin A efficacy is increased when used in combination with other Vitamins like C & E.
- All forms of vitamin A are unstable under UV light so use at night only and use an SPF in the day.
- Avoid in pregnancy