As many of you probably know, I’m a huge Skinceuticals fan. (A mix of clinically-proven ingredients, plus optimized delivery systems in many of their formulations and exceptional, ingredient-stabilized packaging? Count me in!) That said, I’ve often gotten the question of which Skinceuticals product to choose, the Skinceuticals Retinol 0.5 or the Skinceuticals Glycolic 10 Renew Overnight.
There are many myths about the differences between retinol and glycolic acid. In truth, both are superior ingredients for fighting fine lines and wrinkles, skin sagging, sunspots, and for exfoliating the skin. And, in actuality, although many experts recommend retinol for dry skin and glycolic acid for oily skin, I’m the opposite: Only glycolic acid has been shown to increase hydrating hyaluronic acid content in the skin over time, whereas retinol has not.
Retinol vs. Glycolic Acid
The truth is, which to choose depends on your skin type and concerns. Below, I’ve outlined some of the similarities and differences:
Both Retinol and Glycolic Acid
- Have been shown in peer-reviewed journals to increase skin thickness (Journal of Investigative Dermatology (retinol); Journal of the American Academy of Dermatology (glycolic acid)).
- Increase collagen fiber density within the skin. Although it’s commonly believed that retinoids help with fine lines, wrinkles, and skin sagging through increases in collagen production and glycolic acid doesn’t, this is not true, as both retinoids and glycolic acid can do this using different mechanisms within the skin (The Journal of Clinical Investigation (retinol); Journal of the American Academy of Dermatology (glycolic acid)).
- Aid in the reduction of sunspots. This is the opposite of fighting fine lines and wrinkles: Although it’s commonly believed glycolic acid fights sunspots and retinoids don’t, in reality, studies have shown both do, but using different mechanisms. Retinol can help to re-organize clumped melanocytes that form sunspots and separates melanocytes that are stuck together and thereby increases cellular turnover, and glycolic acid also dissolves bonds that holds melanocytes together (Photochemistry and Photobiology (retinol); Journal of Cosmetic Dermatology (glycolic acid)).
- Increase cell turnover by accelerating the rate of separation of skin cells that are held together (same sources as above).
- Elevates matrix metalloproteinase (MMP) levels within the skin, which takes down the enzymes that dissolve collagen (The Journal of Clinical Investigation).
- Inhibits c-jun, a protein complex that is associated with degradation of collagen within the skin (The Journal of Clinical Investigation).
Glycolic Acid Only
- Increases natural hyaluronic acid content within the skin with regular use over time (Dermatological Surgery).
- Increases interleukin-1 alpha release, which may help take down inflammation within the skin (Experimental Dermatology).
Skinceuticals Retinol 0.5 – Best for Oily, Acne-Prone Skin; Better Formulation than Skinceuticals Glycolic 10 Renew Overnight
Skinceuticals Retinol 0.5 (or Skinceuticals Retinol 1.0, for that matter) are excellently-formulated products. The retinol is microencapsulated, for one thing, so the retinol doesn’t irritate the skin as much as a full dose of retinol that isn’t slowly released into the skin, and the retinol also is protected from degradation. Furthermore, the packaging is amazing here; the tube has a very small, pinhole size opening, and the tube doesn’t allow for the product to travel backwards in the tube, so you’re keeping out a lot of light, heat, and air.
Skinceuticals Glycolic 10 Renew Overnight – Best for Dry Skin
Skinceuticals Glycolic 10 is a better choice for dry skin than retinol, because, although both glycolic acid and retinol initially dry out the skin, only hyaluronic acid will naturally increase hyaluronic acid content within the skin after a few weeks (Dermatological Surgery).
However, this product isn’t formulated as well as it could be, if I’m being honest. Skinceuticals Glycolic 10 has to be shaken, for one thing, meaning that the ingredients separate quite a bit when it’s just sitting on your counter. This is one thing if you’re spending, like, $10 for a product, but this product is $84 and I’m like, What?! The packaging also doesn’t keep out light, heat, and air as well as the Skinceuticals Retinol 0.5 packaging.
I still recommend this product for dry skin, though, because retinoids can make a mess of dry skin, and because glycolic acid can make oily skin even more oily with regular use over time.
I’m going on the record against the grain here and citing research to back me up: Retinoids fight wrinkles and sunspots, and glycolic acid fights sunspots and wrinkles. Furthermore, I feel strongly that retinoids are best for oily and acne-prone skin, whereas glycolic acid is better for dry skin, because only the latter increases hyaluronic acid production in the skin over time.
***Please note: By citing the above studies, I am stating certain ingredients are proven in peer-reviewed research journals to have effects in the skin. I am not making direct claims that the products listed, or any other products, have effects in the skin.