In this post I’m going to teach you how to make three different hyaluronic acid serums; one with 3 ingredients, one with 5, and one with 8. Each formulation builds on the one before it so you can see how to modify and expand on (or, if done in reverse, simplify!) a serum formulation.

I’ve packed this post full of helpful links, so for the best learning experience please click through and read the ‘bonus’ material as well. Happy making!

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3 ingredients

This first formulation is as simple as it gets; it’s just an effective concentration of hyaluronic acid diluted in water, with an appropriate level of preservative. Easy peasy!

Hyaluronic acid

Our star ingredient! It is a fabulous humectant and moisturizer that we include in our formulations for incredible hydration and skin plumping. Hyaluronic acid also has undeniable label appeal!

There are two key considerations/sorta-challenges when working with hyaluronic acid: it’s slow to hydrate, and is expensive (generally around $5–7USD/g as of early 2023, though this varies a lot by where you live + how much you buy).

We tackle the slow-to-dissolve challenge by making a 1% stock solution of hyaluronic acid which is then stored and ready to use whenever you need it. I usually make 100–200g at a time, and that’ll generally last me a couple months. I like to make a 1% solution as it’s easy to make, easy to work with, and keeps the math of formulating with it pretty simple. If your formulation includes 10% of your 1% hyaluronic acid stock, the final formulation contains 0.1% hyaluronic acid.

Start Here: How to make a 1% hyaluronic acid stock

Hyaluronic acid is available in a variety of different weights—basically, how big the molecule is. I use what is generally called “low molecular weight”. From Simple Skincare Science: “The hyaluronic you want to use should be between 80,000 to 1,000,000 daltons (80 – 1,000 kDa). This seems to be the sweet spot according to studies. Anything higher won’t do much good. Anything lower might cause inflammation.”

Learn More: Hyaluronic Acid for Skin Explained (25 Studies): EVERYTHING You Need to Know! from Simple Skincare Science

A 1% solution of low molecular weight hyaluronic acid creates a viscous, but pourable liquid. Higher weights will create more viscous solutions; lower weights will create less viscous solutions.

Even more info: Hyaluronic acid Q&A

Regarding that high price tag—we’re looking to get the benefits of hyaluronic acid for the lowest cost, a.k.a. we want to use the minimum effective dose. Thankfully for our wallets, hyaluronic acid is effective at quite low concentrations. Studies mentioned in the article linked above found 0.05–0.2% hyaluronic acid to be beneficial. Another study mentioned in that article (you really should read the whole thing, it’s wonderful!) found that “hydration tends to teeter off after 2% in volume”, and for that reason “if you’re formulating your own products, [Simple Skincare Science] recommend[s] keeping the HA concentration below 2%.”

I usually use 0.2% hyaluronic acid in my formulations, which is 20% of that 1% stock solution. This works out to just over $1USD of hyaluronic acid per 100g (3.5oz) batch of a formulation. You could use more, but I rarely do in order to keep costs down.

An added bonus of the stock solution: the far more forgiving margin of error when weighing it out. If you accidentally weigh out an extra 0.1g of the solution that’s ~$0.001 of extra hyaluronic acid vs. $0.1 if it was pure hyaluronic acid powder.

Distilled water

This is what forms the bulk of the formulation; it dilutes the hyaluronic acid to an effective level and hydrates the skin.

Preservative

Because this formulation contains water, it requires a broad-spectrum preservative. I’m using Liquid Germall™ Plus (INCI: Propylene Glycol, Diazolidinyl Urea, Iodopropynyl Butylcarbamate) as it’s very easy to use and works brilliant in hydrous formulations like this one.

Because my 1% hyaluronic acid stock contains 0.5% Liquid Germall™ Plus, that means this formulation already contains 0.1% Liquid Germall™ Plus. To keep the usage rate within the maximum recommended range, I’ll be adding another 0.4% Liquid Germall™ Plus to the formulation for a total of 0.5% Liquid Germall™ Plus.

The Formulation

Super Simple Hyaluronic Acid Solution

47.76g | 79.6% distilled water
12g | 20% low molecular weight 1% hyaluronic acid solution (USA / New Zealand)
0.24g | 0.4% Liquid Germall Plus™ (USA / Canada)

Weigh everything into a beaker, and stir to combine. That’s it!

This solution is quite thin, so I recommend packaging it in a bottle with a dropper top or an orifice reducer.

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5 ingredients

For our next formulation we’ll add two relatively common ingredients to give this 5-ingredient version more of a skincare punch and a serum-y feel.

Panthenol (Vitamin B5)

Panthenol (Vitamin B5) is one of my favourite skin care actives. It’s inexpensive, widely available, effective, and adds all kinds of great benefits to our formulations. It boosts moisturizing, softens the skin, and stimulates skin-regeneration. It’s also soothing. Booyah!

I’m using powdered panthenol (Vitamin B5); if yours is liquid, please read the free Humblebee & Me DIY Encyclopedia entry on panthenol (Vitamin B5) to learn how to use that instead.

Xanthan gum

The 3-ingredient formulation is quite watery as there isn’t enough hyaluronic acid in it to give much of a viscosity boost. While you could use extra hyaluronic acid to thicken the formulation, that’s a very expensive strategy. It’s sort of like using your most expensive extra virgin olive oil to lubricate your lawnmower—there are other ways to do that job that are cheaper and just as (if not more) effective!

A small amount of soft xanthan gum gives this 5-ingredient formulation a wee viscosity boost, resulting in a product that feels more serum-y. If you only have regular xanthan gum I’d use half the amount, adjusting the distilled water to keep the formulation adding up to 100%.

Save 20% on soft xanthan gum and everything else at Formulator Sample Shop with coupon code HUMBLEBEE

If you don’t have xanthan gum you could try a different gelling ingredient or gum instead; I think a 1-for-1 swap to Polyacrylate crosspolymer-6 (Sepimax ZEN), Ammonium Acryloyldimethyltaurate/VP Copolymer (Aristoflex AVC)Hydroxyethylcellulose, or Solagum AX could work well. Other gelling ingredients could work well, too—try it and see!

The Formulation

Soothing Hyaluronic Acid Serum

0.18g | 0.3% xanthan gum (soft) (USA)
0.24g | 0.4% Liquid Germall Plus™ (USA / Canada)

12g | 20% low molecular weight 1% hyaluronic acid solution (USA / New Zealand)

46.38g | 77.3% distilled water
1.2g | 2% panthenol powder (vitamin B5) (USA / Canada)

Weigh the soft xanthan gum and Liquid Germall™ Plus into a beaker. Stir to combine.

Add the hyaluronic acid solution; stir.

Add the distilled water and panthenol (Vitamin B5); stir.

Cover and leave the mixture to allow the soft xanthan gum time to hydrate and activate.

After 20–30 minutes the soft xanthan gum should be all hydrated. Stir the mixture until uniform, and then it’s ready to package!

This formulation is a bit thicker than the 3-ingredient one, but it’s still pretty fluid. I like a bottle fitted with an orifice reducer for formulations with this level of viscosity; this allows me to shake a few drops into my palm to apply. A bottle with a dropper top will also work.

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8 ingredients

Hydrosol

Swapping 20% of the water in this formulation for a hydrosol of choice (I’m using rose!) adds a bit of gentle scent to the formulation. You can use any hydrosol you like, and you can use more or less to get a stronger (or weaker) scent. Simply adjust the distilled water to keep the formulation adding up to 100%.

You could replace all the distilled water in the formulation with hydrosol, but I usually find this is overkill. 20–40% is generally more than enough to get a noticeable scent.

I like using hydrosols instead of essential oils or fragrance oils to scent watery serums because they’re already water soluble and incorporate really easily. There’s no need for a solubilizer—just swap out some water and you’re off to the races! You also don’t have to worry about maximum usage rates as they’re very gentle.

Save 5% on rose hydrosol and everything else at Essential Wholesale & Labs with coupon code HUMBLEBEE

Allantoin

I love allantoin and think it’s a very under-appreciated, under-utilized ingredient. It’s soothing, boosts skin cell turnover, and is a great moisturizer. It’s effective at low concentrations, and I adore it. Highly recommended! We’re using 0.4% of it, which is an effective dose that will easily dissolve in the formulation (it’s not terribly water soluble).

Hydrolyzed protein

A bit of a liquid hydrolyzed protein—I’m using hydrolyzed rice protein—further boosts the moisturizing properties of the serum. It also gives it a coppery colour. You could use a different liquid hydrolyzed protein, or a water-soluble botanical extract your skin loves would also be lovely.

If you want to use a dry hydrolyzed protein (silk is the only one I’ve found), you’ll want to use it ~0.8–1% as a solid powder is more concentrated than liquid proteins.

The Formulation

Extra Moisturizing Hyaluronic Acid Serum

2.4g | 4% hydrolyzed rice protein (USA / Canada)
0.24g | 0.4% Liquid Germall Plus™ (USA / Canada)
0.18g | 0.3% xanthan gum (soft) (USA)

12g | 20% low molecular weight 1% hyaluronic acid solution (USA / New Zealand)
12g | 20% rose hydrosol (USA / Canada)

1.2g | 2% panthenol powder (vitamin B5) (USA / Canada)
0.24g | 0.4% allantoin (USA / Canada)

31.74g | 52.9% distilled water

Weigh the soft xanthan gum and Liquid Germall™ Plus into a beaker. Stir to combine, and then add the protein. Stir again.

Add the hyaluronic acid solution and rose hydrosol, stirring between additions.

Add the panthenol (Vitamin B5) and allantoin; stir.

Add the distilled water; stir.

Cover and leave the mixture to allow the soft xanthan gum time to hydrate and activate.

After 20–30 minutes the soft xanthan gum should be all hydrated. Stir the mixture until uniform, and then it’s ready to package!

This formulation is a bit thicker than the 3-ingredient one, but it’s still pretty fluid. I like a bottle fitted with an orifice reducer for formulations with this level of viscosity; this allows me to shake a few drops into my palm to apply. A bottle with a dropper top will also work.

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Other Questions

How long will these serums last?

These serums should easily last at least a year—likely closer to 2.

How should I use these serums?

I like to apply hyaluronic acid serums after cleansing and before oil serums and/or creams. If you’re using my Easy DIY Vitamin C Suspension (Just 3 ingredients!) these hyaluronic acid solutions are perfect for palm mixing with it to pre-dissolve the L-ascorbic acid in the moment before use.

For best results, I do recommend following up these serums (and any watery serums/toners/solutions) with a cream or oil serum to help keep the hydration in.

Can I use more hyaluronic acid?

You can, but you don’t need to. It’s a really expensive ingredient, so I opt for a low-but-effective concentration.

Why do big companies use higher concentrations of hyaluronic acid?

Probably because they’ve got far stronger purchasing power than we do, so they can really drive the cost per gram down when they buy their hyaluronic acid 1000kg at a time. Studies have shown 0.2% is effective, but for consumers who haven’t read those studies, 2% sounds better.

Relevant links & further reading

Gifting Disclosure

The Liquid Germall™ Plus, panthenol, and hydrolyzed rice protein were gifted by YellowBee.
The allantoin, rose hydrosol, and niacinamide (Vitamin B3) were gifted by Essential Wholesale.
The soft xanthan gum was gifted by Formulator Sample Shop.
The hyaluronic acid was gifted by Pure Nature.
Links to Amazon are affiliate links.