the klog Daily Protectant Facial Mist

Studies show green tea extract and its catechins (like epigallocatechin gallate (EGCG)) help your skin cells product energy more efficiently and reducing the number of free-radicals that can damage your skin from the inside.

In lab-grown skin models, this translated to younger, healthier, and stronger skin.

There's also good sun protection data; researchers saw less DNA damage and redness on human skin when green tea was applied before UVB exposure. And the more they applied, the better the protection.

Needless to say, this ingredient shouldn't replace your sunscreen. But it is a great supportive ingredient that you can already find in many sunscreens and antioxidant serums.

A 2009 study found a 2% green tea lotion was effective for mild-to-moderate acne thanks to its anti-inflammatory and mild antimicrobial activity.

The quality of the extract matters a lot here:

Good extracts contain 50-90% catechins while lower quality ones are mostly there for marketing. We recommend reaching out to the brand if you have questions about the quality or source of their ingredients.

Human Repeated Insult Patch Testing showed no irritation or sensitization at use concentrations (0.86% in leave-on products and up to 30% as leaf water).

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.

A 2011 study found that cucumber fruit juice can fight free radicals and help protect two proteins that keep skin firm and plump (hyaluronic acid and elastin). This is why it's sometimes considered a potential anti-wrinkle ingredient.

Since this ingredient is usually used at low concentrations (up to 3%), it acts more as a soothing and skin conditioning ingredient than a powerhouse active.

Fun fact: Polyglutamic Acid is found in the Japanese food, natto. It is also being used in cancer treatment studies.

Madecassoside pairs well with other hydrating or antioxidant ingredients like Ascorbic Acid or Hyaluronic Acid.

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.

Its headline job is hydration.

The star polysaccharide in aloe, acemannan, is a humectant that retains moisture and helps reduce trans-epidermal water loss.

Aloe also has real soothing credentials; it contains anti-inflammatory compounds like bradykinase and C-glucosyl chromone that help calm irritation and redness.

On the repair side, lab work shows that acemannan wakes up your skin's repair cells (fibroblasts), prompting them to multiply and speed up healing.

There's some human data for cosmetic benefit too: a cream containing 10% Aloe Barbadensis leaf extract improved skin hydration and elasticity in a real-use study.

Safety-wise, this ingredient is well-regarded with just one rare downside; there have been some case reports of acute eczema, contact urticaria, and dermatitis in people who applied aloe-derived ingredients topically. Those with a known aloe or Liliaceae sensitivity should patch test.

Typical use levels range widely, from under 1% up to 90%+ depending on the format and the effect you are after.

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.

Research shows it can encourage your skin cells to turn over and renew by stimulating keratinocyte and fibroblast proliferation.

It also has mild keratolytic properties to help loosen and shed dead skin cells without being harsh.

Studies also suggest allantoin can help calm inflammation by dialing down some of the chemical signals your skin sends out when it is irritated.

This ingredient is typically used in the 0.1-0.5% range, and the FDA recognizes it as a skin protectant in OTC products up to 2%.

Overall, allantoin is a wonderful addition to most routines; it is stable across a wide pH range (~4-8), works well with other ingredients, and is considered non-sensitizing/non-irritating.

Fun fact: Allantoin is naturally occurring in comfrey root, beets, chamomile, and wheat sprouts. Our bodies even produce it as a byproduct of uric acid metabolism.

Topical use is generally considered safe but allergic or sensitive reactions are possible. Be sure to patch test.

This is why Europe's medicines regulator has approved calendula extracts as a traditional remedy for minor skin inflammation and healing small wounds.

The stronger human evidence is around would/ulcer care rather than everyday cosmetic claims; a review that pulled together 14 studies found that calendula helped calm the early, inflamed stage of a wound and helped new skin tissue form faster.

Two studies also showed it shrank leg ulcers (the kind caused by poor circulation). Results were mixed for burns and for the skin irritation people get from radiation treatment, so it's not a sure thing there.

In cosmetics, it's mostly a skin conditioning and soothing agent.

The Cosmetic Ingredient Review panel concluded that calendula-derived ingredients are safe as used and that the ingredients are not irritating, sensitizing, or photosensitizing in clinical tests (though they may be mild eye irritants).

Typical use levels are quite low; industry data reported it used at under 0.5% (one supplier noted a 10-25% extract blend used at 1-10% in the finished product). Historical use goes up to 10%.

The only thing to keep in mind is if you have daisy/ragweed allergies. Calendula is in the same family and one patch-test study found 2% of dermatitis patients reacted to marigold. Be sure to patch test if you have sensitive or allergy-prone skin.

Research shows it can help:

It also pairs nicely with hydrating ingredients like niacinamide and ceramides.

Just so you know, Propolis Extract is recognized as a contact allergen. In patch tests done in the EU, roughly 1-6% of patients react to it. Be sure to steer clear of this ingredient if you have a known allergy to bee products.

Since it is an animal-derived product, this ingredient is not considered vegan. For vegan alternatives, check out Galactomyces Ferment Filtrate or Centella Asiatica Extract.

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.

This ingredient is water-soluble.

Heart Leaf is rich in flavonoids such as quercetin, apigenin, and more. It also contains polysaccharides, the most common type of carbs in food.

Flavonoids have been shown to be effective antioxidants. They help neutralize free-radical molecules. Free-radical molecules are unstable molecules that may damage our skin cells and DNA. The flavonoids in Heart Leaf also help soothe the skin.

Polysaccharides are naturally found in our skin. They play a role in hydrating and repairing the top layer of skin. The polysaccharides in Heart Leaf help moisturize our skin.

Studies show decanoyl acetaldehyde, a component of Heart Leaf oil, is effective at killing bacteria.

The name 'Fish Mint' comes from the herb's natural fishy smell. Is is native to southeast Asia and used throughout the continent for traditional cooking and medicine.

Ancient Chinese medicine has used peony root to treat dark spots, but studies are looking into this claim more.

Rosmarinic acid has been shown to calm inflammation signaling in skin cells (the same pathways that flare up in conditions like eczema and psoriasis). It also has real antimicrobial and antifungal activity in test-tube studies.

This ingredient is typically used in low concentrations (generally well under 1%) where it acts as a light fragrance + mild skin soother extract.

The main thing to know is that lavender contains two naturally fragrant molecules: Linalool and Linalyl Acetate. Some people's skin does perfectly fine with fragrance while others don't.

Just be sure to patch test if you have reactive skin or known plant allergies.

Linalool and Linalyl Acetate are gentle when fresh but oxidize into compounds that can cause allergic contact dermatitis when exposed to air. Patch-test studies of patients already being investigated for skin allergies found about 5-7% of patients had reactions to oxidized linalool, and 2.8% of patients reacted to oxidized lavender oil.

This combination is not really found in any other plant oil and is the reason this is one of the most stable botanical oils available.

Some studies show it to be more stable than jojoba oil, helps a product resist going rancid, and can help extend the shelf life of a formula.

It also naturally contains vitamin E and phytosterols that give it a mild antioxidant benefit.

This ingredient is typically used from around 1% to fairly high levels since it's gentle; it's well-tolerated and low on the irritation scale.

Typical use concentrations range from 2-3% and it works across a pH of 4.5-8.5.

This ingredient has been found safe to use in cosmetics and has a low irritation profile.

Because it's build on stearic acid, it may not be fungal acne safe. Stearic acid is a C18 fatty acid that falls within the range (C11-24) that Malassezia can feed on.

It is also an emollient and helps condition the skin.

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!

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.

D-panthenol is also known as dexpanthenol. Most cosmetics use dexpanthenol or a mixture of D and L-panthenol.

Panthenol is famous due to its ability to go deeper into the skin's layers. Using this ingredient has numerous pros (and no cons):

Like hyaluronic acid, panthenol is a humectant. Humectants are able to bind and hold large amounts of water to keep skin hydrated.

This ingredient works well for wound healing. It works by increasing tissue in the wound and helps close open wounds.

Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.

This ingredient is also referred to as pro-vitamin B5.

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%.

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.

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

Methylpropanediol is able to add a bit of moisture to the skin. It also helps other ingredients be better absorbed into the skin, such as salicylic acid.

Studies show SAP has anti-acne and antioxidant benefits. One study found 5% of SAP lotion to be an effective ingredient for treating acne vulgaris. This is because research shows that SAP may help control acne by reducing acne-causing bacteria and slowing the oxidation of skin oils caused by UV exposure.

In addition to acne, vitamin C is important for skin structure. Lab studies suggest SAP may support collagen production in skin cells, making it a great ingredient in anti-aging routines.

Vitamin C has many benefits: it helps reduce redness, improve skin texture, fade the appearance of dark spots, and brighten the skin.

Read more about other types of Vitamin C:

It plays several roles in a formula:

Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.

Multiple assessments have found it to be non-irritating and non-sensitizing to most people.

However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.

Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.

Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.

Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.

This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.

A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.

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.

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%.