Salad Code Sebum Balance Serum

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.

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.

Lab studies on human skin show it calms inflammation by reducing inflammatory signals in skin cells without causing cell damage.

Cell and formulation studies also point to whitening/brightening + anti-wrinkle effects; the extracts from the leaf, seed, and flower showed measurable elastase (wrinkle-related enzyme) and tyrosinase (pigment related enzyme) inhibition.

A cream containing lotus extract also no significant irritation and stayed stable over a month of storage.

Typical usage in cosmetics is usually on the lower end (~0.5-5%) depending on the formula.

Allergy-wise, this ingredient is considered low risk and often included in products made for sensitive/irritated skin. But like any plant extract, it carries a small possibility of contact allergy in people sensitive to plant extracts.

Your skin can't convert salicin to salicylic acid because it needs specific enzymes that aren't present on the skin's surface. It won't behave like true salicylic acid, especially at the concentrations used in cosmetics.

However, this ingredient has its own perks. It contains flavonoids, polyphenols, and tannins that give it proven antioxidant and soothing properties.

An 8-week clinical study found a cream with 2% of this extract improved skin microcirculation, elasticity, and dark circles. This is most likely due to its role in increasing hyaluronic acid synthesis in fibroblasts and improved vascular integrity.

Another study found a topical serum with 0.5% salicin showed improvements in visible signs of aging, hyperpigmentation, and texture.

Just be careful if you have a known aspirin/salicylate allergy and be sure to consult with a medical professional about using this ingredient if you do.

Fun fact: Willow Bark extract has been used for thousands of years and ancient civilizations used white willow to help treat pain and fevers.

Grape extract also helps soothe and hydrate your skin.

Compared to newer derivaties like glucosylrutin, rutin is less water-soluble and stable.

On top of that, soybean oil is rich in vitamins like vitamin E, a potent antioxidant.

Research on soybean's active components also point to anti-inflammatory, collagen-stimulating, antioxidant activity, and protection against UV-induced oxidative damage.

Most of this research applies to the broader soybean plant and not just the oil fraction alone.

This ingredient does carry a comedogenic rating of 3 from the old rabbit-ear assay. Just remember testing finished products in humans showed that formulas built with "comedogenic" ingredients are not necessarily comedogenic themselves. It's worth patch testing if you're breakout prone, and always listen to your skin.

Because this ingredient is a saturated triglyceride, it may not be fungal acne safe. This is because Malassezia breaks down sebum triglycerides into fatty acids it can consume, making this ingredient a possible source for the yeast.

This ingredient is considered hypoallergenic and non-toxic. Cellulose Gum can be found in cosmetics, food, and other household goods such as paper products.

Is it bad for your skin?

The answer comes down to concentration. Patch and wash studies have found highly concentrated alcohol-based hand rubs (60-100%) cause less barrier disruption than washing with a basic detergent like SLS. The only measurable effect in these studies was a temporary dip in skin hydration.

Concentrations below 12-15% in leave-on cosmetics is generally well-tolerated. Concentrations above start to see increased transepidermal water loss (TEWL) and reduced hydration.

In concentrations about 58%, it creates temporary channels in your skin's lipid layers to become more permeable and allow other ingredients to slip through easily.

This ingredient can be up to 80% of the formula in alcohol-based perfumes.

Overall, this ingredient is probably harmless if found lower down an ingredients list but worth side-eyeing if it's high up (especially if your barrier is already struggling).

Alcohol can worsen dry skin, eczema, and oily skin, especially at higher concentrations. This is because it can increase transepidermal water loss and decrease hydration to disrupt the skin barrier.

According to the National Rosacea Society based in the US, you should be mindful of products with these alcohols in the top half of ingredients.

True allergic contact dermatitis to ethanol is uncommon, but be sure to patch test if you have dry or sensitive skin.

Furanocoumarins bind and destabilize your DNA to increase the rate of sunburn.

Most reputable companies will remove furanocoumarins from their formulations.

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.

You should know this ingredient is a known EU fragrance allergen.

Animal studies classifies this ingredient as a weak-to-moderate skin sensitizer and clinical patch testing on eczema patients confirmed it to be both a contact allergen and irritant.

The term 'citral' is a collective term for two geometric isomers: geranial/Citral A and neral/Citral B.

The term '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.

There's some lab work behind its reputation; in one study, it acted as an antioxidant and calmed inflammation in human immune cells. But it also killed skin cells (keratinocytes) in a dish.

It stopped damaging those cells and still reduced swelling in mice when the researchers wrapped it in tiny capsules to slow its release.

One study that is quoted out of context frequently: clove oil killed human skin and blood vessel cells at levels as low as 0.03%, and about 73% of that came down to eugenol. Keep in mind those were bare cells sitting in a dish with no skin barrier in the way (which is a lot harsher than what happens on your actual face).

On concentrations, it is restricted to 0.64% in leave-on products + body products, 0.21% in baby + lip products, 2.5% in fine fragrance and 4.9% in rinse-off. Real formulas usually land far below those caps.

Allergy is the actual story with this ingredient. It is one of the eight markers dermatologists use for allergy testing, and the EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

It is also a prohapten, meaning it needs enzymatic activation in skin to become allergenic, so sensitivity varies between people.

Rates are modest but not trivial: in a classic EECDRG multicentre study, 13 of about 1,300 patch-tested patients reacted to eugenol, and in eugenol-allergic subjects the lowest positive patch test concentration was 0.031%, with 56% reacting in a 21-day repeated open application test at 0.5% to 2.7%.

Normal use levels are generally fine if you are not already sensitized.

Geraniol can be found in many essential oils including Rose Oil and Citronella Oil. The scent of Geraniol is often described as "rose-like". Many foods also contain Geraniol for fruit flavoring.

Geraniol can irritate the skin when exposed to air. However, irritation depends on the ability of geraniol to penetrate into the skin. In general, geraniol is not able to penetrate skin easily.

Geraniol is colorless and has low water-solubility. However, it is soluble in common organic solvents.

Like citronellol, it is a natural insect repellent.

2,6-Octadien-1-ol, 3,7-dimethyl-, (2E)-

You'll typically see this ingredient used in very small amounts; anything above 0.001% in a leave-on product or 0.01% in a rinse-off has to be named on the label in the EU. The citrus oils that carry it sit around 0.5-1% in a finished formula.

Fresh limonene is a weak allergen; the real issue is that it slowly reacts with air and then breaks down from oxidation to create hydroperoxides (which are strong sensitizers). This is why suppliers are required to keep the peroxide value below 20 mmol.

Positive reactions in people being investigated for eczema vary:

It's worth skipping if you have a known fragrance allergy or a compromised barrier, but the risk is low for most people.

Older or long-opened products are also more likely to bother you than fresh ones due to oxidation.

The EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

Fresh linalool is a weak sensitizer but air exposure turns some of it into hydroperoxides, which are strong sensitizers. Those oxidation products are the actual allergy concern.

Patch-test clinics see positive reactions to linalool hydroperoxides in about 4% to 12% of dermatitis patients depending on country and test concentration.

Resassuringly, one analytical study found hydroperoxide levels in real fragranced products to be orders of magnitude below what induced sensitization in animal studies with no evidence of oxidation building up during normal storage.

The practical takeaway is that linalool is fine for most people but worth avoiding if you have a confirmed fragrance contact allergy or a badly compromised barrier.

Products stored a long time after opening are also the high-risk scenario since that is when oxidation happens.

The scent of linalool is described as floral, spicy tropical, and citrus-like.