hyaluronic acid serum

Hyaluronic acid: the benefits in skincare.

This post will make clarity on the benefits of hyaluronic acid for the skin and help you understand what kind you should be buying.

If you like to research ingredients and facts before making a purchase, you're probably facing an overwhelming number of information.

What I do when I feel overwhelmed? 

Absolutely nothing. 

I don't take any action which can worse than making a temporary wrong decision.

THIS IS THE PROBLEM: too many options to choose from- a plethora of cosmetic ingredients. 

Each one of them promises wonders.

How do you decide what to focus on?

There’s no univocal answer to this question, but I can share what I do as both cosmetic chemist and skincare junkie.

I focus on ingredients that

1) have scientific evidence supporting their action and

2) have a long history of usage with relatively no side effects.

This is why
I ALWAYS include hyaluronic acid in my own formulations and in most of the formulations I develop for clients.

What skincare products contain hyaluronic acid?

Hyaluronic acid is a staple ingredient in skincare.

You can find it in serums, eye creams, lotions, and even rinse off products.

There are also hyaluronic acid supplements to be taken orally.  

You can recognize it from the names  hyaluronic acid and sodium hyaluronate.


As a cosmetic chemist I know how some ingredients get the hype and then disappear after a few months.
But I'm also aware that 
there are ingredients that never lose their popularity.

Hyaluronic acid is one of these winners. 

Here's why.

It’s safe and effective.

SAFE as it has a low irritation potential.

EFFECTIVE as several scientific studies confirm its activity.

If you're interested in discovering the amazing properties and skincare benefits of hyaluronic acid, keep on reading.

(OR if you don't feel like reading, watch this video below which is a short summary of the article).

What is Hyaluronic acid?

From a chemistry stand point, hyaluronic acid is a polymer. 

A polymer is a structure that consists in a large number of similar units bonded together.
In the case of hyaluronic acid the units are glucuronic acid linked to N-Acetyl- Glucosamine.

Hyaluronic acid is usually sold as sodium salt (sodium hyaluronate-powder), which releases hyaluronic acid in water.  I want to point out that hyaluronic acid and sodium hyaluronate are the same thing because of what stated above. The reason why sometimes the sodium salt is used is merely solubility. Salts are always more soluble in water than the correspondent  acids or bases.

The most important take home message is that Hyaluronic acid comes in different forms which have different molecular weights.
In fact, polymers have different weights, just like people. Molecular weight is determined by the number of units present in the polymer. The more, the heaviest.

  • High molecular weight HA ( 1.5 MDA). DA means Dalton which is a unit measure for weight. It's the equivalent to oz for very small weights such as molecules.
  • Low molecular weight HA (50kD).
  • Extra Low molecular weight HA.
  • Crosslinked HA (rare in skincare).

In the skincare industry, hyaluronic acid is considered a *humectant moisturizer.* It’s also useful for scars and wound healing.

When I write about Hyaluronic acid on Quora, people ask me all the time why I'm a strong proponent of high molecular weight and why I did not include medium or low molecular weight hyaluronic acid in the serum I developed.


Does Hyaluronic acid really work ? How does Hyaluronic acid work?

Let's answer these two questions.

Hyaluronic acid is naturally present in the skin.
However, its content decreases with aging, and the most visible effects are *the loss of facial skin hydration, elasticity and volume, which are responsible for wrinkles.* This is how HA works as anti-age agent.

If you’ve been following my content, you should know that I’m always radically transparent; therefore, I must point out that *the anti-age activity has not been proven in clinical trials yet. However, when applied topically on the face, you'll definitely note a reduction in the appearance of fine lines and wrinkles. This is mostly due to the fact hyaluronic acid is able to  draw and retain moisture from the environment and give it to your dehydrated skin.

Over the last few years, HA has been widely used as a biomaterial to develop dermal fillers (DFs), which are medical devices that, injected into or under the skin, restore lost volumes and correct facial imperfections such as wrinkles or scars. This is the most effective way to take advantage of HA anti-aging properties.

Does this mean that skincare products that contain HA  are just a waste of money?

​Actually, hyaluronic acid moisturizers and serums , when properly formulated, are among the simplest yet most effective products.

Here’s why.

HIGH MOLECULAR WEIGHT HA works as a *film-forming polymer:* it reduces water evaporation, with an occlusive-like action. Unlike other occlusive agents, though, it creates a cosmetically elegant film , rather than an oily thick and sticky barrier. The feel is light on the skin, the serum promptly absorbed so that you can apply a moisturizer right after it. 

 This is the main advantage of using it.

On the other hand,*MEDIUM and LOW MOLECULAR WEIGHT HA*mainly work by binding moisture from the environment meaning they act as humectants rather than moisturizers. In some cases, this capacity may reverse HA’s expected hydrating activity as at a high concentration, HA may even extract humidity from the skin, leaving it even more dry.

Furthermore, as this brilliant article explains in details, medium and low molecular weight HA are pro-inflammatory. These two forms of hyaluronic acid should be avoided especially when the skin barrier is already damaged and fragile.

The importance of the skin barrier.

Do you know what determines the overall appearance of the skin?

Water content.

"Barrier function,  skin elasticity, and resistance are all dependent on water content".

We all use moisturizers because we tend to have dry skin, right?

As we age, barrier function tends to become compromised. The worsening of the barrier function manifest itself with an increase in *TEWL* which stands for trans epidermal water loss. This basically means the skin loses more water than it is supposed to, thus becoming dry and dehydrated.

Hyaluronic acid is an humectant meaning it is able to draw water from the dermis (deep skin layer) to the epidermis (the portion of the skin that we can touch- the most external one).

This is why the immediate effect of using it is a plumper and hydrated skin which basically means nothing but a healthy skin. 

Another approach to tackle dry skin is the use of creams that contain humectant ingredients; the most common humectants are glycerin, hyaluronic acid, sorbitol. urea, propylene/ butylene Glycol and its natural version propanediol.

 However, when the skin barrier is damaged creams that only contain these ingredients not only can’t help, but they actually draw even more water from the skin, especially when used in very dry climates.

The best approach to tackle dry skin is the use of creams that contain *occlusive ingredients* (for example petrolatum a.k.a vaseline or lanolin). The problem is these creams are usually greasy, and therefore, not well tolerated, especially on the face. Furthermore, petrolatum and lanolin have raised health and environmental concerns.

The way these barrier creams work is by forming a hydrophobic (= water repellent) layer on the skin surface. This *mechanically* prevents water loss.

Instead of improving the situation, they actually make it worse.

Emollient ingredients help with dry skin, too, by improving softness, smoothness, and elasticity. Examples of emollients are fatty acids and alcohols or *vegetable oils.*

Extra dry skin benefits from the application of both , creams and oils.

Where does Hyaluronic acid stand?

As stated above, hyaluronic acid is an humectant moisturizer ingredient. But we have seen not all hyaluronic acids are equivalent.
High molecular weight HA is the only form that work as both, *humectant AND occlusive.*

This is a huge advantage.

Using a product with high molecular weight hyaluronic acid allows you to have the benefits of occlusive ingredients without their downsides (“heavy” formulations that are tacky and greasy) AND an dramatic increase in moisture due to its humectant properties.

Skincare products based on hyaluronic acid- The benefits. 

Topical hyaluronic acid represents a moisturizing active ingredient widely used in cosmetic formulations (gels, emulsions or serums) to restore the physiological microenvironment typical (and the look, of course) of youthful skin.
HA’s hydrating effect largely depends on its molecular weight.

If you start including Hyaluronic acid in your skincare routine, you’ll notice skin looks plumper, softer, and smoother .

However, please remember that the skin is an organ and skincare products are no magic bullet, no matter how good they are. If you don’t sleep enough, your diet is off , and you rarely exercise, nothing will work.
Sadly you’ll end up switching from one product to another without any improvement.

This is why some people claim hyaluronic acid actually made their skin worse. 

Hyaluronic acid : skincare routine for dehydrated skin.

dry skin

Avoid drying harsh cleansers. If it’s a face related issue, use micellar water or an oil based product rather than foaming cleansers. In particular, avoid all cleansers that contain sodium lauryl sulphate (SLS) and other anionic surfactants . These have an excellent cleaning and foaming power, yet tend to be aggressive. As a general rule, look at the foam. The more foam a product makes, the more aggressive it is.

Do not wash more than twice /day (face) and once / day body. If you don’t wear makeup, cleaning the face once /day is more than enough. If you feel you need to refresh it throughout the day, spray some water 

A great micellar water is the Bioderma Sensibio


In the morning , after you clean, apply a hyaluronic acid serum and layer it up with a moisturizer . 


At night, before going to sleep apply a moisturizer. The more occlusive, the better. So for instance even basic petrolatum will do. Our moisturizer does a great job in tackling dry skin. Remember that daily moisturizers can be used at night as well. 

If you have dry and dehydrated skin you should limit alcohol intake and drink plenty of water. 

June 2020 update. During summer the skin tends to produce more oil. For this reason, you might have to slightly change your skincare routine. A moisturizer might not be necessary during these months.

A high molecular weight hyaluronic acid serum is one of your skin's allies during summer. Not only it tackles skin dehydration and dryness, it also helps to repair sun damaged skin. 

By now you should feel quite enthusiastic about hyaluronic acid! 

​It should definitely belong to your skincare routine. 

Have questions? Leave them in the comments below.

37 thoughts on “Hyaluronic acid: the benefits in skincare.

  1. Chris Evans says:

    Great article – but don’t believe I’ve ever seen a manufacturer put molecular weight on a product, so how would we know?

  2. Megan Adler says:

    Thanks for helping me learn more about hyaluronic acid and the benefits we can obtain by using it. Lately, my skin has been very dry and I’ve used a couple of products but none seem to help. I’m going to add an HA cream to my beauty routine and hopefully, this will do the trick.

  3. lucy says:

    Hello! Could you please tell me how an “occlusive” moisturerizer can help my skin? I would think that anything “occlusive” would prevent absorption. Thank you

      • Cam says:

        Thanks for the reply Luisa! I just ordered your products! Excited to receive it.

        What is Vit C for?
        Also, do you have eye creams that you sell? If not, what do you recommend for dark circles, dry and aging eye area and just wanting general maintenance. At the moment Im using Dermalogica products.

        • Luisa says:

          Hi Cam, vitamin C is an excellent antioxidant that can help fighting aging. At higher percentages (at least 10%) also works as lightening agent. It’s impossible for me to recommend you a product without having more information about you, but in general I think one of the best brands out there is Paula’s Choice.

  4. Melissa says:

    Hi, I am in my mid 40s and inherited very oily skin, and it has been a lifelong struggle. What products would you suggest to help reduce oil production? I cleanse once daily with a non-foaming gel that contains activated charcoal and marine algae. My skin feels very pleasant afterwards. I don’t wear makeup because it slides off, so at night I only splash cool water on my face, and pat dry. I live in a subtropical climate, so sweating is a daily event. Thanks so much, I look forward to your response!

  5. Patty says:

    You mention above “these are 2 other options”. But there is nothing there. Can you recommend a moisturizer for night? Thank you

  6. Sarah says:

    Thank you so much for the article and all of the details and work you put into this. What is your opinion on Juice Beauty products? More overpriced hype or beneficial? I do like the idea of more natural ingredients, but I also want them to work.

    • Luisa says:

      I really like the concept behind Juice Beauty. However, I wonder how effective are the products. This is because instead of using the active ingredient, they use all natural extracts. Natural extracts vary a lot in terms of concentration of active ingredients depending on many different factors such as how the plant has been grown and harvested, how the extract has been made etc etc. As usual, it something works for you, stick to it.

  7. Debbie says:

    If using the all over body spray that you manufacture , together with your Hyaluronic acid , would you still suggest using a moisturizer such as clinique?

  8. Nikki Smith says:

    Hi Luisa,

    I am trying to buy high molecular HA Hyaluronic Acid to put into a formulation I am making at school. Where can I find it in its purest form? Is hyaluronic acid unstable on its own? Will I need to put in additives to make it stable? I am trying to make a natural product. Thank you for your help!


  9. Diane says:

    I have been researching microneedling with a derma roller at home. Do I apply your hyaluronic acid 1% gel before or after I use a derma roller? Do I also need to apply vitamin C at the same time?

    • Luisa says:

      I would use it AFTER. But you need to make sure it’s the high molecular weight one. Low and medium weights have a pro-inflammatory action which can be exacerbated by the use of a derma roller. Conversely, high molecular weight HA hydrate and accelerate recovery. You can apply vitamin C at night.

  10. Muriel says:

    Hi Luisa. I am interested in buying your Hyaluronic acid. I have rosacea which is exacerbated by any oils used in skincare. I see your HA has only 3 ingredients but they are not listed. Would you mind sharing those three ingredients or let me know if it contains oil? Thanks very much!

    • Julia says:

      Should Hyaluronic acid be avoided in dry climates with very low humidity like Arizona? If it should be avoided then what should I use instead of Hyaluronic acid for dehydrated skin ?

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