Formulating with Vitamin A in skincare

Does vitamin A get absorbed by the skin?

Yes. It has good epidermal penetration, in a variety of forms. Enzymes within the skin are able to readily convert various forms of vitamin A to its active, retinoic acid form.

Studies have also shown it does not increase plasma levels of vitamin A when applied to the skin, meaning that although it is absorbed easily by the epidermis, it does not make its way into the blood stream, providing effective transient skin benefits only.

What forms of vitamin A are used in cosmetics?

It is important to explain at this early stage, that the ‘active’ form of vitamin A within the skin recognized and used by receptors is trans-retinoic acid, also known as tretinoin.

Retinoic acid (tretinoin) is known to regulate skin keratinocyte growth and differentiation.

While there is significant clinical evidence for the efficacy of retinoic acid/tretinoin to be effective to reduce photodamage, hyperpigmentation spots, fine lines and wrinkles, this particular form of vitamin A is also very irritating and has suspected teratogenic effects.  

Because of its significant risks with use, both retinoic acid and tretinoin are BANNED for use in cosmetics, and are only permitted in pharmaceutical or therapeutic goods, under prescription use.

The types of vitamin A you will see in cosmetics include (going from least popular to most popular):

• retinaldehyde – this is easily converted within the skin to retinoic acid, and also provides very similar benefits but with lower irritancy. It is not as wide spread in skincare as retinol and retinyl palmitate forms.
• retinyl propionate – another rarely used form, it is less irritating and more stable than retinol, with similar performance.
• retinyl acetate – increasing in popularity, this form is less irritating and more stable than retinol, with similar performance.
• retinyl palmitate – another commonly used form, this retinol ester is very low-to-non-irritating but has much weaker activity than retinol, but is more stable in formulas.  
• retinol – the most popular form of vitamin A in skincare because its performance is quite similar to retinoic acid, but it can be very irritating. Retinol is limited by input in some regions, so check your local regulations carefully before using in your cosmetic formulas in case restrictions apply.

Retinol and its derivatives are only beneficial in leave on skin care products; it is not effective in wash off products.

When should retinol and its derivatives be used with caution (or avoided)?

Because of its known potential irritation, retinol should be avoided in skin care products for those with sensitive skin, as well as babies and children.

It has significant skin renewal performance, so it should also be avoided in sun care products, but is suitable in after sun products where there is no sun exposure.

Because it can be toxic in high quantities when ingested, it should not be used in lip care products where incidental ingestion could be significant over the course of a day.

What are some formulation issues when formulating with retinol?

Retinol is relatively unstable, so must be formulated to a pH between 6-7. You will need to use a sodium citrate buffer to maintain this pH range throughout the product’s shelf life, or monitor stability testing carefully to ensure it remains constant.

You also need to avoid heat during processing, and only add it when the formula is <40°C.

Retinol and its derivatives are oil soluble, so you need to ensure they are held stable within the oil continuous phase of a formula. You may also need to dilute or mix them with oil before adding them to a formula, depending on the form you use.

An antioxidant ingredient to protect the formula is required, while adding anti-irritant ingredients such as allantoin or alpha-bisabolol are highly recommended.

Find out more about formulating with vitamin A by watching this video:

What do the regulators have to say about the use of retinol and its derivatives?

Remember: tretinoin, retinoic acid and its salts are PROHIBITED in cosmetic products worldwide.

Regulatory status can change at any time. At the time of this post (8^th February, 2022), the regulatory status of vitamin A and its derivatives in major regions is:

• Australia: vitamin A limited to 1%w/w in cosmetic products
• ASEAN: as for EU
• Canada: limited to 1%w/w retinol/RE; 1.15%w/w retinyl acetate and 1.83%w/w retinyl palmitate
• China: not listed however safety limits of other countries should be observed
• EU: while no limit is specified in their regulations, SCCS opinions recommend the following inputs as ‘safe’:
  • hand and face creams: 0.3% RE
  • body lotions: 0.05%RE
• Japan: not listed however safety limits of other countries should be observed
• NZ: refer to Australia or EU limits to ensure safe use
• South Korea: not listed however safety limits of other countries should be observed
• USA: CIR-reviews recommend current use should be maintained at 1%w/w or less

Please remember it is the responsibility of the brand putting their product on the market to ensure their product, its claims and ingredients are compliant with the region in which it will be sold. Please make sure you run up to date regulatory checks to ensure safety and compliance of your brand.

Learn how to check and ensure regulatory compliance with our Certificate in Cosmetic Regulatory Essentials.

How do you calculate IU and RE?

If you need to convert the amount of retinol in your retinol derivative, please use this recognized table:

Source: SCCS Opinion on Vitamin A, 2016; accessed 08/02/2022.

What are the alternatives to vitamin A?

We are seeing more and more innovative launches for vitamin A alternatives. Please watch this video to find out more:

You can also refer to our summary table below: