SCIENCE BEHIND THE BEST CREAM WITH RETINOIDS
Retinoids, such as retinol and retinoic acid (tretinoin), are the anti-aging ingredients with the greatest scientific guarantee. But what is the best retinoid cream on the market? It must provide high-quality retinoids, at a concentration with clinical effect, and in a formula that guarantees its stability. Here I make a list of the best retinoid products and explain their composition.
What are retinoids?
Retinoids are a group of compounds that include vitamin A (or pure pharmacy retinol) and other natural derivatives of vitamin A, such as retinaldehyde, retinyl esters, and retinoic acid. Obtained through diet, retinoids play an important role in the quality of our bones, eyes and skin (see more about retinoids and their metabolism).
Science behind the use of retinoids in the skin
Retinoids, and specifically retinol and retinoic acid, are the anti-aging ingredients with the greatest scientific endorsement. They have been studied in depth for more than 40 years in well-designed and independent clinical trials, which have proven their effectiveness against wrinkles and other signs of aging. Also, they have been shown to be safe for health when used topically (see more on retinoids and scientific studies).
Retinoids are not recommended if you are pregnant, planning a pregnancy, or are breastfeeding.
Scientifically proven
benefits of retinoids on the skin The benefits of retinoic acid and retinol on the skin, demonstrated in clinical studies, are multiple:
Promote the proliferation and regeneration of skin cells
Stimulate collagen production in the dermis reducing wrinkles and sagging skin
Prevent collagen degradation caused by environmental factors
Lighten the skin and prevent pigmentation by reducing the formation of epidermal melanin .
They act as antioxidants that neutralize oxidant molecules (free radicals). This reduces skin damage caused by environmental factors (such as the sun and pollution).
They reduce acne by preventing dead cells from clogging pores, and also by their anti-inflammatory effect.
What is the difference between retinoic acid, retinol, and retinyl esters on a cosmetic level?
Retinoic acid: the most powerful, but the most irritating (requires a prescription)
Retinoic acid is the most powerful and stable of all retinoids, as it is the active form of vitamin A. That is, it does not require transformation, it can trigger responses on skin cells immediately and directly. Any other retinoid has to be transformed into retinoic acid, and therefore its effectiveness may decrease during the transformation.
However, retinoic acid has side effects when used on the skin. These include dryness, redness, burning, peeling, and peeling of the skin. Despite these side effects at the beginning of use, the skin tends to adapt. For its purchase you need a prescription.
Pharmacy Retinol (Pure) – Powerful with Fewer Side Effects
Pure retinol has to be oxidized several times to form retinoic acid (the active form). It is first metabolized to retinaldehyde and finally to retinoic acid (two transformations). Pharmacy 0.2% retinol is said to equal 0.01% retinoic acid, and is therefore less potent. However, clinical studies show that it has clear anti-aging benefits when used for a long time.
Retinol has the advantage that it is better tolerated than retinoic acid, and does not usually cause irritation. After use the skin may turn a little reddish and a little itching or dryness is also common, but it is generally softer. The disadvantage of retinol is its instability, exposure to the sun and light can inactivate it before it has been converted to retinoic acid. Therefore, it is of the utmost importance that the formulation of the cream or serum guarantees its long-term stability.
Retinyl esters: lower potency, with the advantage of not causing irritation and being more stable
Retinyl esters, such as retinyl acetate, retinyl propionate and retinyl palmitate, are used in most cosmetics because they are more stable and less irritating. They are an excellent option to start using retinoids and adapt to the skin, for young people, or with sensitive skin. Although they have anti-aging effects, they lack the potency and scientific endorsement that pure retinol and retinoic acid have.
What retinoid should I use based on my skin type and age?
In the guide (below) I give more guidelines for each specific product. But overall:
They can be used as of 25 years of age.
If the skin is very sensitive or is not adapted to the use of retinoids, start with retinoids that are not very potent, such as retinyl esters, or slightly irritating, such as retinoic acid esters (granative retinoids) -> see products below
For those over 30 -40 years I recommend using retinoids whose anti-aging results have great scientific endorsement, these are pharmacy retinol (see below), retinaldehyde, and retinoic acid.
The potency level of retinoids according to the transformation (oxidation) steps to retinoic acid is:
Retinoic acid or tretinoin (active form): does not have to be transformed, the most powerful
Retinoic acid ester (as granative retinoids): one transformation step (DOES NOT USUALLY IRRITATE)
Retinaldehyde: one transformation step
Pure retinol: two transformation steps
Ester Retinyl: three transformation steps, the least potent (NOT USUALLY IRRITATING)
How long should retinoids be used?
Clinical studies show that although retinoids can improve facial skin in as little as 2 months, their anti-aging and sun protection effect is much more pronounced with prolonged use, and more evident after 6 to 12 months. Therefore, it is advisable to prolong its use and be patient, as there is a progressive improvement over time.