How to compare the strength of retinoid products
When looking at retinoid products, you’ll often find them in the form of creams or gels. Most products mention two crucial pieces of information:
- The type of retinoid, such as retinol or retinaldehyde
- The concentration of the retinoid
These two factors combined determine the overall strength of the product, which can make it challenging to compare different retinoid products directly. For example, it may be difficult to compare a 1% retinol product to a 0.1% retinal product.
Types of retinoids and their potency
To understand the strength of a retinoid product, it’s essential to know about the different types of retinoids and their relative potency. For a more detailed explanation, you can refer to our guide on types and strengths of retinoids.
In brief, different types of retinoids require a varying number of steps before they can be used by your skin. The fewer steps required, the more potent or “stronger” the retinoid is generally considered to be.
Here’s a rough ranking of retinoid strength, from strongest to weakest:
- Tazarotene
- Tretinoin, adapalene
- Retinaldehyde (retinal)
- Retinol
When comparing the strengths of products, this ranking is an important factor to consider.
The case of retinol and retinal
Some companies claim that retinal is 10 times stronger than retinol. However, there is limited clinical evidence to support this specific claim. For eaxmple, there was a study[1] that found retinol and retinal had similar efficacy at concentrations of 0.05% and 0.1%.
Other companies suggest that retinal works up to 10 times faster than retinol. There is some evidence[2] that suggests that retinal works up to 11 times as fast as retinol in cultured human keratinocytes.
Challenges in comparing product strengths
Because there are two factors at play (type of retinoid and concentration), it’s difficult to make exact comparisons between the strengths of different retinoid products. On top of that, the limited clinical evidence doesn’t always support claims made by companies.
However, you can compare these two factors individually:
-
Type of retinoid: Using the potency ranking above, you can compare different types of retinoids. For example, a 0.1% retinal product should work faster than a 0.1% retinol product.
-
Concentration: For the same type of retinoid, a higher concentration will be stronger. For instance, a 0.5% retinol product would be stronger than a 0.1% retinol product.
As you start using retinoids, you can move up the strength ladder by either using a stronger retinoid or by increasing the concentration of the retinoid.
