Osmosis Beauty Correct Preventative Retinal Serum

In skincare, PC pulls double duty:

The linoleic acid it carries gets incorporated into skin ceramides and helps reinforce the lipid matrix.

Interestingly, it can help top of the omega-6 fatty acid that's often low in acne-prone and atopic skin. There's a sizeable body of literature that supports its use in dry, barrier-impaired, and breakout-prone skin.

There are two kinds of PC you'll see on ingredient lists.

Use levels range from <1% as a liposomal carrier and between 20-40% in lamellar matrix sytems.

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%.

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.

Once applied to your skin, enzymes gradually break down the cyclodextrin "ring"; this releases the active ingredient in a controlled way.

You'll usually find this in concentrations between 0.2-5%.

Fun fact: This ingredient is commonly used as food additive in Japan.

Because retinal only requires 1 conversion step to become retinoic acid, it's the strongest over-the-counter retinoid. It also works at lower concentrations than retinol, since retinal is about 10x more bioavailable.

Studies back up its efficacy in skin:

A foundational trial showed that applying 0.05-0.5% retinal for 1-3 months produced a dose-dependent and significant increase in epidermal thickness + cell turnover markers.

And a head-to-head comparison of 0.05% retinal against a 0.05% retinoid acid found both formulations were effective for the basis of wrinkle/skin roughness features, but retinoic acid caused more local irritation.

More recent controlled trials confirm it improves wrinkles, dermal density, and firmness over 12-24 weeks, with significant improvements in skin texture and firmness (particularly with the higher 0.1% concentration).

Retinal also has one trick the other retinoids do not: it directly fights against acne bacteria since a clinical study showed retinaldehyde-treated areas displayed a significant decrease in counts of viable P. acnes.

This makes it a great pick for people who want to treat aging and breakouts.

Typical cosmetic use sits in the 0.05-0.1% range with 0.05% being the gentle starting point and 0.1% giving stronger results.

Like all retinoids, retinal works best with nightly use, a good moisturizer, and daytime sunscreen. It can cause some irritation so ease into it slowly rather than going all in.

The "ramp up" method works well: start with Retinal once a week to give your skin time to adjust, which keeps irritation low.

Slowly add more nights until you reach your goal frequency once your skin feels comfortable.

Retinoids also make your skin more sensitive to the sun in the first few weeks, so wear sunscreen every morning and protect your skin from direct sun while you build up tolerance.

What is a matrikine-mimetic compound?

This peptide has the ability to mimic matrikines in skin. Our skin created matrikines by breaking down matrix proteins into peptides.

Matrikines play a role in:

Though further research is needed, this ingredient seems pretty promising. In one study, women over the age of 40 with visible photoaging used a vitamin C serum with this ingredient for 56 days (15% ascorbid acid, 5 ppm palmitoyl tripeptide‐38). The results found improvement in skin roughness and skin tone.

This peptide is also part of the famous Matrixyl synthe’6, a blend of ingredients that also includes glycerin, water, and hydroxypropyl cyclodextrin.

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here:

On the surface, it acts as a humectant that holds water in place and reduces moisture loss for a plumper, smoother feel, while its anti-inflammatory and antioxidant properties make it a great pick for calming redness or sensitive skin

The more interesting story is underneath:

Despite its large molecular size, oat beta-glucan has been shown to penetrate the epidermis and reach the dermis by slipping between skin cells. Here, it interacts with fibroblasts and macrophages to nudge collagen synthesis and support wound repair.

A small 2005 split-face clinical study of 27 subjects found topical beta-glucan produced measurable reductions in wrinkle depth, height, and roughness after 8 weeks of use.

It is worth noting the trial was small and the penetration testing used frozen, irradiated skin so the anti-aging data is encouraging rather than definitive.

This ingredient gets along with pretty much everything and is typically used around 0.1-1%.

Fungal acne: This ingredient is not a food source for the Malassezia yeast because it is a glucose polysaccharide with no fatty acid or ester component.

Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells. The antioxidants in Alpha Lipoic Acid have been shown to fight damage from cigarette smoke.

Studies also show Alpha Lipoic Acid plays a role in wound healing.

Thioctic Acid will break down when exposed to sunlight.

Many foods contain thioctic acid, including tomato, brussel sprouts, spinach, and broccoli.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

When exposed to air, these two compounds become strong allergens. This ingredient exhibits cytotoxicity at low concentrations; amounts of 0.25% have been shown to damage skin cells.

A study from Japan found this ingredient caused lavender sensitivity after widespread exposure.

Lavender essential oil has some antimicrobial, antibacterial, and anti-inflammatory properties. However, the cons of this ingredient may outweight the pros.

More research is needed to confirm lavender essential oil's effects when used in aromatherapy.

Lavandula Angustifolia is known as the English Lavender and famous for creating purple fields in Provence, France.

Like all essential oils, this ingredient is a known sensitizer at higher concentrations. This is because this oil also contains known skin-irritating fragrances, limonene and camphor. Limonene and camphor are both known EU allergens.

While patchouli oil holds FDA GRAS ("generally recognized as safe") status, it is typically used at low levels and subject to usage guidelines.

Those with sensitive skin should patch test before using.

Honeysuckle contains flavonoids and saponins. Both of these components are natural antioxidants that can help soothe the skin.

As most flowers do, honeysuckle has a natural fragrance.

This honeysuckle is native to East Asia and used in traditional Chinese medicine to treat fever and inflammation.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

This ingredient gets a bad rep because it is irritating and drying due to its astringent property. Astringents draw out natural oils in tissue to constrict pores and dry out your skin.

However, alcohol denat. is not all that bad.

Due to its low molecular weight, alcohol denat. tends to evaporate quickly. One study on pig skin found half of applied alcohol evaporated in 10 seconds and less than 3% stayed on skin.

This also helps other ingredients become better absorbed upon application.

Studies are conflicted about whether this ingredient causes skin dehydration. One study from 2005 found adding emollients to propanol-based sanitizer decreased skin dryness and irritation. Another study found irritation only occurs if your skin is already damaged.

Small amounts of alcohol are generally tolerated by oily skin or people who live in humid environments.

The rule of thumb is this ingredient will probably not affect your skin much if it is near the end of an ingredients list.

One thing to note:
People with ALDH2 (aldehyde dehydrogenase 2) deficiency may experience skin irritation from continued alcohol use. About 8% of the world's population have this deficiency.

The Cosmetic Ingredient Review Expert Panel has determined denatured alcohols to be safe for use in concentrations between 0.05% and 12% (depending on which denaturant is used).

Also...

This ingredient has antimicrobial and solvent properties.

The antimicrobial property helps preserve products and increase their shelf life. As a solvent, it helps dissolve other ingredients.

Look for formulas that contain glycerin, hyaluronic acid, or panthenol if you want to offset any drying effect.

This ingredient will trip away your skin's natural oils/lipids that help it lock in moisture. This can worsen dryness, trigger eczema flare-ups, and aggravate rosacea.

Be sure to patch test any product with this ingredient if you have dry or sensitive skin, eczema, or rosacea.

According to a manufacturer, it also offer some moisturizing effects.

As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.

The sensitization picture is actually quite assuring as well:of nearly 71,000 patients patch tested with benzyl alcohol, only 0.21% showed a positive reaction with most of them being weakly positive.

This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.

It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.

Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.

At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.