The Derma Co 5% Nia-Ceramide Mattifying Moisturizer Versus Dr. Sheth's Oil-Free Moisturizer

This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.

A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.

Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.

Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.

Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.

Studies show conditions like atopic dermatitis can worsen when ceramide NS levels are low.

Aging, harsh cleansers, environmental damage, or skin conditions can cause ceramide levels to drop. This leads to moisture loss, irritation, and dryness.

This is where this ingredient steps in: it's structurally designed with the same key features as natural ceramides. Because of this, it can slot into the lipid layers of your stratum corneum and behave just like real ceramides.

Research on patients with atopic dermatitis, seborrheic dermatitis, and sensitive skin has shown that topical application of this ingredient enhances stratum corneum function.

Another four-week randomized study on lip care found formulas containing 0.5% or 2% of this ingredient improved lip dryness and roughness.

A study on hairdressers with occupational hand dermatitis found that a barrier cream containing this ingredient reduced dryness, scaling, cracking, redness, and itching.

And a more recent study confirmed that this ingredient is absorbed into the stratum corneum and reduces transepidermal water loss (TEWL), just like a real ceramide.

This ingredient is more stable, free from contaminants, and significantly cheaper to produce. This makes it more practical for everyday skincare formulations.

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

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:

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

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!