Lierac The Micellar Water Versus Dermaceutic Laboratoire Oxybiome Cleansing Micellar Water

Any antioxidant and soothing claims mostly come from those polysaccharides; crude laminarin and fucoidan from Laminaria digitata do show antioxidant and anti-inflammatory activity in lab assays.

Just know that the lab assays are test-tube work on isolated compounds and not clinical trials on the finished extract.

Realistically, this ingredient is a nice-feeling and hydrating skin conditioner (not really an active).

Safety-wise, it's one of the better documented seaweeds and safe to be used in cosmetics according to the CIR Expert Panel.

Industry surveys find that usage concentrations run can be found up to 5% in bubble baths and leave-on usage is more likely 0.1-3%.

The risk of allergy is also quite low as human repeat insult patch tests (under 5% and blends containing 8-12%) came back non-irritating and non-sensitizing. Rabbit studies came back negative too, though one trade mixture at 1.5-2.5% in water + propylene glycol did cause moderate irritation at 30 minutes.

Reported seaweed allergies in the literature are almost all occupational (people handling wet kelp) or from a totally unrelated blue/green alga.

At this time, there's actually no published comedogenicity test on it and the evidence that does exist points away from clogging.

Laminaria Digitata Extract has never been run through the rabbit ear assay or the Mills & Kligman human model and it isn't in Fulton's 1989 list of tested comedogenic ratings.

The CIR's brown algae review pulled every published and unpublished study industry had on 82 seaweed ingredients and found no comedogenicity data for any of them.

So any number you see online was assigned by a person and not actually measured.

In 2012, Capitanio et al. ran an 8-week double-blind, vehicle-controlled trial in 60 people with mild acne using a Laminaria digitata-derived oligosaccharide complexed with 0.1% zinc pyrrolidone.

They found comedones, papules and pustules dropped significantly more in the active group than the vehicle group at 2, 4 and 8 weeks.

Caveats for this study: a Laminaria digitata-derived oligosaccharide is just fraction and not the plain extract, and the zinc is likely doing real work. Still, the study found comedones went down in acne-prone skin.

This fits mechanistically. Comedogenesis is largely a lipid story and this is water-soluble polysaccharides, minerals, and polyphenols. There's nothing really to plug a follicle with.

The real caveat is the carrier: some supplier versions come dispersed in caprylic/capric triglycerides.

The 0-5 scale comes from applying ingredients to the inside of an albino rabbit's ear. Rabbit follicles are far more reactive than human ones so it over-predicts. Even petrolatum was reassigned as non-comedogenic by the original scientist, Kligman.

Here are three more problems of comedogenic ratings:

Either way, you're getting water + a cocktail of minerals and trace elements (like magnesium, calcium, potassium sodium, etc).

Officially, COSIng recognizes this ingredient as a humectant that holds and retains moisture, and solvent that helps dissolve other ingredients.

The claims about this ingredient come from its minerals. A 2025 systematic review found that seawater-based therapy showed moderate effectiveness at reducing atopic dermatitis severity and improving skin barrier function.

It also showed favorable safety profile and very minimal adverse effects.

The underlying studies pointed to improvements in stratum corneum hydration, lower transepidermal water loss (TEWL), and a healthier microbial balance.

Much of this benefit is actually attributed to magnesium: a 2005 study found that bathing in a magnesium-rich Dead sea salt solution improved skin barrier function, boosted hydration, and reduced inflammation in atopic dry skin.

It's worth nothing most of this evidence comes from bathing/soaking protocols and mineral-rich waters like the Dead Sea (not necessarily a few drops on an ingredient list).

Overall, this is a gentle, well-tolerated, water-phase ingredient that can offer light hydration and a little mineral boost.

The only caveat is that very high salt concentrations can be drying for already-dry skin.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

Like other alcohols, this ingredient helps prevent the growth of bacteria. However, its main purpose is to impact a fragrance.

Specifically, saccharide Isomerate is a humectant. Humectants draw moisture from the air to our skin.

Research shows Saccharide Isomerate to be an effective moisturizer.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!