Sensilis Pure Age Perfection Cicacne Serum

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Mandelic acid helps with:

Due to it having a larger molecular size than glycolic acid, mandelic acid is able to penetrate the skin more slowly and evenly. This makes it gentler and less irritating, making it a great option for sensitive or beginner skin.

Despite being milder, mandelic acid is still an effective exfoliant that improves skin texture and tone over time.

What makes mandelic acid stand out from other AHAs? It has antibacterial and antioxidant properties.

These traits make it a great option for acne-prone or problem skin by reducing active breakouts and fading post-acne marks. Studies show that mandelic acid (especially when combined with salicylic acid) can significantly reduce pimples and hyperpigmentation while causing fewer side effects than stronger acids.

Mandelic acid is effective in concentrations of 5% and up with an ideal pH range of 3-4 for at-home use.

Like other AHAs, it’s important to wear sunscreen daily to protect your newly exfoliated skin.

However, unlike glycolic acid, mandelic acid is light-sensitive. Be sure your mandelic acid is packaged in opaque containers to ensure it stays stable and effective.

In short, mandelic acid is a gentle yet powerful AHA that exfoliates, brightens, and helps clarify skin while keeping irritation low. Its antibacterial action makes it especially beneficial for those with acne-prone, sensitive, or uneven skin, offering smoother, clearer, and more even-toned results over time.

Read more about some other popular AHA's here:

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

The zinc part slows down an enzyme that turns testosterone into DHT, the hormone that tells your oil glands to pump out more sebum. Less of that signal means less oil. It also gently fights acne-causing bacteria and soothes redness/irritation.

This is why Zinc PCA often shows up in products for oily, breakout-prone skin and greasy scalps.

One lab study also hinted it might have a small anti-aging perk because it seemed to protect collagen from UVA damage and even helped the skin make a bit more of it. That last bit is still early research done in a dish and not real skin, so take it as a nice bonus rather than a promise for now.

As for scar healing, the picture is more "maybe" than a firm yes. Zinc itself plays a real role in wound repair because it is a cofactor for the enzymes involved in collagen building, calming inflammation, and helping new skin cells cover a wound. Lower zinc levels are also linked to slower healing.

Most of the scar healing research is on zinc oxide or oral zinc rather than zinc PCA specifically, with a focus on healing fresh wounds instead of scars that are already there.

Direct evidence that zinc PCA improves the look of established scars is still limited at this time. Though it would be fair to say zinc PCA supports the general skin-repair environment thanks to its zinc content .

This ingredient is water-soluble and plays nicely with other actives like niacinamide and salicylic acid. It works best at mildly acidic formulas (~4-6 pH) and is effective at low levels. Around 0.1% is enough to be active and finished products commonly use it anywhere up to 4%.

Overall, this is a well-tolerated, low-drama multitasker that suits oily and acne-prone skin.

This is due to its content of terpenoids, polysaccharides, macronutrients, and phenolic acids.

These compounds allow centella to dial back inflammation, encourage the skin to build and hold onto collagen, support the barrier and hydration, and bring solid antioxidant activity to protect against signs of aging.

Centella also carries a nice supporting cast of Vitamin A, vitamin C, several B vitamins, and amino acids. Put it all together and you get an ingredient that soothes, hydrates, and protects, all at once.

Most of centella's magic comes from the four big compounds (Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid). These are the actives doing the heavy lifting in almost every centella study.

Here is the short version of what they do in the skin:

So it is not just soothing for the sake of soothing. Centella calms the skin AND helps it rebuild.

Just FYI, not all centella on an ingredient list is the same. What you are getting actually depends on the extract:

Fun fact on the ratios: the leaves tend to be richest in Madecassoside and Asiaticoside, and lower in the two acids. The exact amounts shift with where the plant is grown and how it is processed. This means purity really does vary brand to brand.

Centella is one of the most easygoing actives out there.

It layers well with basically everything: niacinamide, hyaluronic acid, peptides, and vitamin C, and also pairs nicely with stronger actives like retinoids and exfoliating acids where it can help take the edge off irritation.

On the safety side, centella and its triterpenes are classified as weak sensitizers, meaning allergic reactions are possible but uncommon.

Patch tests at 1% and 5% came back negative in test panels, and creams at typical use levels did not cause allergic reactions across large groups of people.

But as with any new active, a patch test is still a smart move for very reactive skin.

Centella is widely used because it is effective at low percentages. For context, human safety testing found no meaningful irritation from creams containing centella extract at everyday use levels (the tested amounts were well under 1%).

The irritancy threshold in animal testing was also above 30% (so real-world formulas sit far below anything concerning).

In collagen lab studies, higher concentrations drove more collagen synthesis, so serums built around centella tend to feature it more prominently.

Bottom line: you will find centella working nicely anywhere from a fraction of a percent up to hero-ingredient levels depending on whether it is a supporting soother or the main event.

Fun fact: Centella has been used as a medicine and in food for many centuries. As a medicine, it is used to treat burns, scratches, and wounds.

One component, glabridin, has extra potent antioxidant and soothing properties. It has also been found to block pigmentation from UVB rays in guinea pigs.

Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.

Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.

Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.

Licorice root is native to Southern Europe and Asia. It has been used in traditional Chinese medicine to help with respiratory issues.

Rather than being brewed in bacteria, it's grown inside Nicotiana benthamiana, a tobacco relative used as a tiny plant "factory" (a technique called molecular farming that's well documented in the scientific literature for producing functional human growth factors).

In a formula, this ingredient acts as an anti-aging and skin conditioning active.

TGF-β2 is a signaling molecule that switches on the pathway in your skin to stimulate the synthesis of collagen I and support the skin's own lipid production.

This is why manufacturer's pitch it as a retinol-like alternative. And unlike retinoids, this ingredient doesn't increase your skin's sensitivity to the sun in the first few weeks of use. This makes it suitable for daytime use.

The headline claims for this ingredient come from the manufacturer's own 28 day in vivo studies. They reported reductions in wrinkle count, volume and depth, pore size reduction, and increases in radiance, hydration, firmness, and elasticity.

Though these sound solid, just keep in mind these are company-run trials rather than independent peer-reviewed dermatology papers.

The broader peer-reviewed work mostly backs the production method and the general collagen-stimulating biology of plant made TGF-β2 proteins and not an exact finished product.

One honest caveat: the molecule is large (like collagen) so it likely sits more at the surface rather than penetrating deeply into skin.

Typical concentration use levels are quite low and the actual bioactive protein is only present in trace amounts since growth factors work at very low doses.

One manufacturer claims this ingredient to have a pH range of 2-8 and to be biodegradable.

This ingredient is also known as Sepimax Zen.

This ingredient can also be found in pill medicines to help our bodies digest other ingredients.

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

On the safety side, it's well-studied and has a solid track record. Human repeat-insult patch testing showed no skin irritation or sensitization even at 100%.

Typical use levels are pretty tiny, usually less than 1%.

You might see some fear-mongering around this ingredient:

Studies in male rats showed kidney effects but that's because of a rat-specific protein that humans don't make. So this study isn't really relevant to humans.

Though it's not a typical fragrance like parfum, it does have a natural scent. That's why the official COSIng database lists it as 'perfuming' ingredient. It can be used to modify the scent of a formula.

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.

Though it can't kill microbes on its own, it works as a good supporting agent when combined with other preservatives like Phenoxyethanol or 1,2-Hexanediol.

This ingredient naturally occurs as piceol in Norwegian spruce needles (~0.4-1.1% dry weight and in cloudberries). Though the cosmetic-grade material is synthesized for purity and consistency.

You'll usually see it used at low levels and suppliers recommend up to 1% added to a water phase.

Safety testing was done at concentrations like 0.05% in SPF products and 0.5% in a Human Repeated Insult Patch Test. The safety evidence is assuring; this ingredient is safe for cosmetics in current use and also holds safety status as a food flavoring as well.

An honest caveat: the "soothing" and "anti-inflammatory" claims come mostly from supplier marketing rather than published clinical trials. The Cosmetic Ingredient Review's own literature search found no useful efficacy studies on this ingredient.

So the antioxidant and preservative-boosting roles are the well supported ones while the calming benefit is plausible but thinly evidenced.

Overall, this is a well-tolerated, low-irritation multitasker that quietly helps a formula stay fresh and stable.

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.