Hyaluronic Acid
Hyaluronic Acid
INCISodium Hyaluronate, Hyaluronic Acid, Sodium Acetylated Hyaluronate, Hydrolyzed Sodium Hyaluronate
The molecule that holds a thousand times its weight in water. Naturally found in your own skin. The hydration baseline of modern skincare. Also the most misunderstood ingredient on the label.
What you need to know
What it is
A polysaccharide your body produces naturally. About 50% of the body's hyaluronic acid sits in the skin. Cosmetic HA comes from bacterial fermentation (the rooster comb sourcing was retired decades ago). Available in many molecular weights, each behaving differently on the skin.
What it does
Pulls water into the upper layers of the skin and holds it there. High molecular weight HA forms a film on the surface for instant plumping. Low molecular weight HA penetrates a few cell layers deeper for longer lasting hydration. Multi weight formulas hit both.
Best for
Every skin type that experiences dehydration, which is almost everyone in air conditioning. Particularly good for plumping fine lines that are just dehydration disguised as wrinkles. Compatible with every other active in skincare.
Time to results
Plumping and dewy feel: immediate. Sustained hydration: minutes to hours, depending on layering and climate. Visible reduction in dehydration fine lines: a few days of consistent use.
How it actually works
The HA story is mostly about molecular weight. Same molecule, different sizes, different behaviour.
High molecular weight
Above 1 million Daltons. Too big to penetrate the stratum corneum. Sits on the surface, forms a hydrating film, gives the instant plump and dewy look. Most effective for surface comfort and visual smoothness.
Low molecular weight
Between 50,000 and 200,000 Daltons. Penetrates the upper epidermis. Longer lasting hydration than high MW. Multi weight formulas use both because they target different layers.
Sodium hyaluronate
The salt form of HA, more stable in formulations and slightly smaller than pure HA. Most cosmetic products use sodium hyaluronate rather than acid form. Performance is functionally identical for the user.
Humectant balance
HA is a humectant. In a dry climate with no occlusive layer above, it can pull water from deeper skin layers up to the surface, where it evaporates. Solution: pair HA with a barrier sealer (squalane, ceramides, balm). Or use it on damp skin.
What the clinical data shows
HA is one of the most clinically studied cosmetic ingredients. The evidence covers hydration, fine line plumping, barrier support, and post procedure recovery.
HA can hold up to a thousand times its weight in water in lab conditions
Significant corneometer improvement in multiple 4 to 12 week studies of topical HA at 0.1 to 1% (Pavicic 2011)
Significant reduction in fine line depth at 8 weeks in low MW HA studies. Effect is mostly hydration not collagen.
Endogenous to the human body. Very low irritation across all studied skin types.
Hyaluronic acid vs the alternatives
Glycerin is a smaller, cheaper humectant with strong evidence and lower marketing buzz. HA gives more surface plumping. Glycerin gives more reliable hydration in dry climates. Most well formulated products use both.
Panthenol (provitamin B5) is also a humectant and adds anti inflammatory and barrier repair on top. HA is purer hydration. Layer them.
Different jobs. HA pulls water into the skin (humectant). Ceramides seal water in and rebuild the lipid barrier (occlusive and structural). Always use them together for complete hydration.
HA pulls water in. Squalane seals it. Classic two layer sequence: HA on damp skin first, squalane oil on top to lock everything down. The whole hydration step in one move.
Same molecule, different format. Cosmetic HA sits on or near the skin surface. Injected HA filler is cross linked to last months and is placed in the deep dermis or subcutaneous fat. Topical HA cannot replicate filler results.
Side effects and how to use
Products with hyaluronic acid
Hyaluronic acid is one of the structural hydration ingredients in our Hydra Radiance Rice Milk Toner. Pair with the cleanse, lift and cool steps for a layered hydration routine.
Pair with
Melt Cleansing Balm
Oil to milk cleanseOil to milk cleanse that does not strip the lipid barrier. Sets up the toner step with intact moisture.
Shop the balm → EFRESHMEFairyGlow Wand
LED + microcurrentUse on damp toner soaked skin to press hydration deeper before the air dries the surface.
Shop the wand → EFRESHMEIceLift Facial Globes
Cryo coolingCryo cooling for de puffing. The plump dewy finish HA delivers is even better with vasoconstriction tightening the surface.
Shop the globes →Common questions
What is the difference between hyaluronic acid and sodium hyaluronate?
Sodium hyaluronate is the salt form, slightly smaller, more stable in formulation. Hyaluronic acid is the free acid form. Performance is functionally identical at the cosmetic level. Most products use sodium hyaluronate for formulation reasons. The label can say either.
Why does HA sometimes make my skin feel drier?
HA is a humectant. In dry air with no occlusive layer above it, HA can pull water from deeper skin layers up to the surface where it evaporates. The fix is to apply HA to damp skin and seal it within thirty seconds with a moisturiser, oil, or balm.
Is more HA in a product better?
Not necessarily. HA above about 2% can feel sticky without giving more hydration. The differentiator in good formulas is multi molecular weight rather than total concentration. A formula at 0.5% with three or four molecular weights often outperforms a formula at 2% with one.
Will HA replace my filler?
No. Topical HA sits on or near the surface. Filler is cross linked HA placed deeper in the dermis to last months. They are the same molecule in completely different formats. Topical HA gives surface plumping. Only injected HA replicates injected results.
Can I use HA with vitamin C and retinol?
Yes, all of them. HA is the most universally compatible ingredient in skincare. A common evening routine is vitamin C in the morning, HA serum to a layer, retinoid at night with HA underneath as a hydration buffer.
Is the rooster comb thing true?
Historically yes. Early cosmetic HA was extracted from rooster combs. Since the 1990s the standard source has been bacterial fermentation using Streptococcus equi. Modern HA is vegan, animal free, and higher purity than the rooster comb era.
The evidence
- Pavicic T, et al (2011). Efficacy of cream containing 0.1% HA of different molecular weights. Journal of Drugs in Dermatology.
- Papakonstantinou E, Roth M, Karakiulakis G (2012). Hyaluronic acid: a key molecule in skin aging.
- Bukhari SNA, et al (2018). Hyaluronic acid, a promising skin rejuvenating biomedicine.
- Kawada C, et al (2014). Ingested hyaluronic acid moisturises dry skin. Comparison context for topical claims.
- Salwowska NM, et al (2016). Physiochemical properties and application of hyaluronic acid: a review.