Hyaluronic acid and retinol are some of the most commonly used ingredients in topical skin care products to date, with no signs of slowing down. Though both are shown to improve skin texture and smoothness, hyaluronic acid tends to be more moisturizing and gentle on skin, while retinol is harsher and can be drying to the skin.

Hyaluronic acid is a compound that naturally occurs in the body and provides support, protection, and insulation in connective tissues, especially the skin. Hyaluronic acid has an extremely robust water-binding capacity making it able to promote a plump and hydrated appearance, explaining its popularity across the skin health industry. Topical retinol, on the other hand, is more commonly marketed for its anti-aging effects, including reduced fine lines and wrinkles and improved skin texture. Retinol is distinctly different from hyaluronic acid in that it is not hydrating and in fact often causes dry, peeling, and ultra-sensitive skin. So what are these two ingredients, are there any downsides to using them together, and is there anything you shouldn't mix with them? We’ll discuss these questions in detail throughout this blog.Before deciding whether you should use these two ingredients together, it is important to understand the individual benefits of each. Hyaluronic acid is known as a humectant, a class of ingredients that retains moisture by binding with many times its weight in water. This means that when this moisturizing ingredient is applied to the skin, hyaluronic acid can bind and lock in water molecules, acting as a time-extended water supply to skin cells, thus preventing moisture from leaving your skin¹. So, what do retinoids do? Retinol is more often used to treat specific issues of the skin, including acne and the visible signs of aging. Retinol is able to promote collagen production and regulate oil production, which by extension, helps limit the appearance of wrinkles and fine lines while also reducing the potential for acne to develop².

Not only do retinol and hyaluronic acid serve different purposes, they also often cause different reactions in the skin when applied, making them suitable for different skin types. Hyaluronic acid can be used on almost all skin types, while retinol should be avoided by those who display sensitive or reactive skin. Despite this, they can work well in tandem for certain less reactive skin types, as they complement each other’s shortcomings. For instance, while hyaluronic acid is great at soothing and hydrating the skin, it does not boost cell turnover rate and production as well as retinol. Conversely, retinol ramps up cell turnover rate and collagen production but may leave your skin feeling dry and irritated, which is one of the most common side effects of retinol use³. So by using retinol and hyaluronic acid together, you can create a symbiotic blend that will address many skin health issues while ensuring that your skin remains soothed and unbothered.With hyaluronic acid being such an inert and broadly beneficial ingredient, there are almost no ingredients that will cause an adverse reaction when mixed with hyaluronic acid. In fact, you can benefit by using it alongside harsh ingredients to combat potential irritation or dryness. However, this does not mean that there is no danger with using hyaluronic acid. Due to its high water-binding capacity, applying too much hyaluronic acid may ironically lead to dehydration of the deeper layers of the skin. This occurs when a disproportionate ratio of hyaluronic acid to water is introduced to the skin, leading the hyaluronic acid to draw water from deep within your skin rather than from its surrounding environment, thereby dehydrating the lower layers of skin⁴.

To determine the correct dosage of hyaluronic acid to apply to your skin, you should begin by applying small amounts and working up to larger amounts as your skin becomes accustomed to the application of hyaluronic acid. You should also be sure to apply hyaluronic acid to damp skin, or you can mist the skin with water after applying hyaluronic acid to ensure it has enough external moisture to bind to.Retinol tends to be more reactive than hyaluronic acid. Thus there are a few things to look out for when applying it to the skin in order to prevent adverse reactions. While you can mix retinol with almost any moisturizer or humectant, it’s important to be careful when using ingredients such as vitamin C, alpha hydroxy acid (AHA), and beta hydroxy acid (BHA). The two classes of hydroxy acids can be especially problematic when used with retinol as they have exfoliating properties that can lead to even more irritation alongside retinol⁵. If you want to benefit from the differing properties of both hydroxy acids and retinol, then it is recommended to use them on alternating days as combining them during a single day could easily overwhelm your skin and ultimately damage your skin barrier. On the other hand with vitamin C, it is recommended to use it at a different time during the day. For instance, vitamin C in the morning and retinol at night. This is because the protective antioxidant properties of vitamin C may react unpredictably with the boost to cell turnover rate from retinol, potentially resulting in irritation of the skin⁶.In order to most effectively use retinol alongside hyaluronic acid, it is recommended that you let the retinol product soak into your skin first, with a few key exceptions. This can mean waiting 10-30 minutes after applying your choice of retinol product, allowing it to reach the lower layers of the dermis and begin the process of boosting collagen production ⁷. Once the process has begun, you can lightly dampen the skin and apply hyaluronic acid to seal in the skin’s moisture.

One exception is if the product containing hyaluronic acid contains an active ingredient that you would like to penetrate the most. As a rule of thumb, the first product you apply to the skin will experience the most penetration. So if you have a product that contains hyaluronic acid alongside a hero ingredient, you may consider applying it before retinol or alternating your use of each to achieve full benefits from each active.

For those with drier or more sensitive skin, it's especially important to begin with a low dosage of retinol and then slowly increase the amount of retinol used as long as the skin remains tolerant. By taking these precautionary steps, your skin can acclimate and build a tolerance to retinol, helping to prevent any particularly irritating side effects. Monitoring the condition of your skin will help you articulate when to stop using retinol vs when to lessen your use.With serums or other potent products that contain hard-hitting active ingredients, such as those retinol, it is important to apply them first – before any moisturizers or other products. This is done to allow maximum penetration of the actives into the skin. If a moisturizer with hyaluronic acid is applied before a serum with retinol, it is possible that the retinol will not penetrate as deep into the skin, potentially compromising its efficacy⁸. Even with a serum containing hyaluronic acid, it is recommended that the serum with retinol is applied first so that the hyaluronic acid can draw moisture from the outer layers of skin to the deeper layers where the retinol will need it. Ultimately, the order of your skin routine is totally up to you and your choice of which active ingredients you would like to penetrate the most.The basic routine for using retinol and hyaluronic acid together is quite simple. Begin by cleansing the face with your choice of cleanser. This should then be followed by the application of at most two serums, one of which can contain retinol, allowing them the opportunity to penetrate through the dermis. Lastly, a final splash of water and the application of a peptide moisturizer with hyaluronic acid will be sure to seal in all the moisture that the serums need.OneSkin’s OS-01 FACE Topical Supplement includes three sizes of hyaluronic acid to penetrate each layer of the skin. Super powered by the OS-01 peptide, OS-01 FACE is an ideal product to use alongside a retinol product, as it is ultra-hydrating and soothing to the skin, thereby counteracting retinol’s harsh side effects. When it comes to the order of retinol versus OS-01 FACE, it depends on which action you want to penetrate more - retinol or the OS-01 peptide. You can choose to alternate the order or find which order you prefer based on trial and error. As a rule of thumb, the product that you apply first will experience the most penetration and cause the most effect on the skin.

• While hyaluronic acid and retinol are both known to improve skin texture and smoothness, hyaluronic acid tends to be more hydrating and works well with all skin types, whereas retinol tends to be harsher on skin and is not recommended for sensitive skin types.
• Hyaluronic acid is a moisturizing humectant, a compound with great water retention properties.
• Hyaluronic acid can be used alongside just about any ingredient.
• Retinol should not be used with other potentially irritating agents such as vitamin C, AHA’s, and BHA’s.
• Hyaluronic acid can be used with retinol to offset retinol’s potential irritating side effects.
• Hyaluronic should typically be used after retinol to preserve its effectiveness.

By Philip Tajanko. Philip is studying Bioengineering at the University of California - San Diego and is passionate about scientific writing and hormonal research.

Sources:

1. https://www.sciencedirect.com/topics/medicine-and-dentistry/humectant
2. https://pubmed.ncbi.nlm.nih.gov/17515510/
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6791161/
4. http://barefacedtruth.com/2015/03/31/hyaluronic-acid-yes-size-does-matter/
5. https://pubmed.ncbi.nlm.nih.gov/19245467/
6. https://www.byrdie.com/can-you-use-retinol-and-vitamin-c-together-5220358
7. https://www.byrdie.com/can-you-mix-hyaluronic-acid-and-retinol-5217416
8. https://procoal.co.uk/blogs/beauty/how-to-layer-hyaluronic-acid-and-retinol