Idio Hokkaido PDRN Lotion

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.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

OTC Azelaic acid is usually available in concentrations from 10-15% and anything over requires a prescription.

Here's what each tier does best:

Unlike other acids, azelaic acid will not make your skin more photosensitive/sun sensitive.

Though this ingredient is naturally occurring in grains like wheat, rye, and barley, it is usually synthetically created for cosmetics to ensure stability and effectiveness.

In skincare, it's best known as a brightening ingredient that slows down tyrosinase, the key enzyme that makes skin pigment. It also nudges the skin toward making a lighter type of pigment instead of a darker one.

This is why you'll see it in products aimed at dark spots and uneven tone.

A small number of real human trials have found a topical glutathione lotion:

The honest caveat is that the current evidence is still thin (few studies, small groups, short timelines). Glutathione also doesn't absorb into skin very easily so results tend to be modest and fade if you stop using it.

One thing worth clearing up:

The scary side effects you may have heard about come from glutathione injected intravenously, which has real safety concerns. Applying it topically is a completely different thing and has a clean track record.

Most human studies used it around 2% (as Glutathione or Glutathione Disulfide) and a 2% oxidized glutathione lotion and a 2% S-acyl glutathione cream are the concentrations with actual clinical data behind them.

There's no established "ideal" percentage yet but 1-2% is the evidence-backed range.

Allergy-wise, there is very low risk for this ingredient; it was well-tolerated across the topical trials. Only one participant had mild temporary redness that cleared up on its own and another study reported no adverse reactions at all.

One trial had ~10% of users drop out for irritation was using a combination cream that also had 10% azelaic acid so the irritation likely wasn't from the glutathione. There's no notable contact-allergy signal for topical glutathione in the literature but patch-testing before first use is still sensible for those with sensitive skin.

That conversion happens in two steps: your skin first turns Retinol into Retinaldehyde (also called Retinal), then turns Retinaldehyde into Retinoic Acid.

Retinol is converted to biologically active retinoic acid via retinaldehyde by dehydrogenases in a two-step oxidation process.

Each step is a little "upgrade" toward the active form which is part of why Retinol is gentler than prescription Retinoic Acid; your skin does the work gradually. This also explains where Retinol sits in the retinoid family.

Here is the retinoid family ranked roughly by strength: Retinyl Esters (like Retinyl Palmitate) < Retinol < Retinaldehyde < Retinoic Acid.

Retinoid activity increases in that order, while tolerance runs in reverse; retinyl esters are the gentlest and retinoic acid the most irritating.

The more conversion steps an ingredient needs, the gentler (and slower) it tends to be, so Retinol lands in a nice middle spot. It's more effective than the esters, gentler than prescription options.

Once it becomes Retinoic Acid, it binds to receptors inside your cells' nuclei (called RARs and RXRs). These receptor pairs bind to specific DNA motifs called retinoic acid response elements and act like switches that turn certain genes on or off.

In practice, this means a few things happen in a formula. It:

That last two are worth a closer look.

A study that tested Retinol directly (not just prescription Retinoic Acid) found that four weeks of retinol thickened the epidermis and switched on the genes for Collagen I and Collagen III, with more procollagen I and III showing up in the skin. And after twelve weeks, facial wrinkles were visibly reduced.

Retinoids more broadly stimulate the skin's synthesis of hyaluronan and other glycosaminoglycans, part of what gives skin a plumper, more hydrated look over time.

So even the gentler OTC form is doing real structural work (not just sitting on the surface).

It's also worth knowing Retinol isn't only a wrinkle ingredient; it can help with uneven tone, dark spots, rough texture, and the look of pores as well because it speeds up turnover and influences pigment.

The research backs this up as well.

A pooled analysis of six clinical studies found that 0.1% stabilized retinol improved all signs of photoaging versus vehicle as early as week 4 and through 12 weeks, with only a few mild cases of irritation.

Another study comparing concentrations found that 0.3% and 1% Retinol were similarly effective at remodeling photodamaged skin, but 0.3% caused fewer adverse reactions when used daily (a useful reminder that more isn't always better).

Retinol is about tenfold less potent than Retinoic Acid. This is why it works as a gentler, non-prescription option that builds results over time.

Typical concentrations range from 0.1-1%, with 0.1% to 0.3% being a well-supported sweet spot for visible benefits with good tolerability.

One quirk worth mentioning: Retinol is famously unstable.

It's highly sensitive to light and oxygen, and UV exposure breaks it down into a range of degradation products.

Real-world testing bears this out, with retinoid content in some products dropping anywhere from 0% to 80% after six months at room temperature, and even more at higher temperatures.

This is why good formulations lean on opaque, air-tight packaging (think tubes and pumps, not clear jars) and often "encapsulate" the Retinol to shield it.

Signs of oxidation include your product turning yellow or smelling "off". Keeping it somewhere cool and dark, and using it up within a few months of opening helps it stay effective.

The most common side effects are mild and temporary: usually some dryness, redness, or light peeling as your skin adjusts. These tend to settle with consistent and lower-frequency use.

Like all retinoids, Retinol works best with nightly use, a good moisturizer, and daytime sunscreen.

The "ramp up" method works well: start with Retinol 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.

One safety note: topical Retinoids aren't recommended during pregnancy or breastfeeding. Systemic absorption from creams is low but because high oral vitamin A is a known teratogen and topical safety data are limited, most clinicians recommend stopping retinoids when pregnant or trying to conceive.

First, Retinyl Palmitate is created from Palmitic Acid and Retinol. It is a Retinol ester and considered one of the weaker forms of retinoid.

This is because all retinoids have to be converted to Tretinoin, AKA Retinoic Acid.

Retinyl Palmitate is pretty far down the line and has to go through multiple conversions before its effects are seen. Once it's on your skin, enzymes called esterases convert it into Retinol, then into Retinal, and finally into Retinoic Acid; that's three steps with a little lost at each one.

The benefits of Retinyl Palmitate are debated due to this long and ineffective conversion line.

So why use it at all?

The answer is stability. Retinol and Retinoic Acid break down fast when they hit light, heat, and air, and Retinoic Acid can be pretty irritating on top of that.

Retinyl Palmitate is much more stable and gentler, making it easier to formulate with and easier on sensitive skin (even if it's weaker gram for gram).

Studies show Retinyl Palmitate to help:

Newer research from 2023-2025 also found that Retinyl Palmitate works especially well when paired with Retinol. The two seem to cover each other's weak spots; retinol brings the potency while Retinyl Palmitate brings the stability and gentleness. Together, they repair UV damage better than either one does alone.

This ingredient used to be found in sunscreens to boost the efficacy of sunscreen filters.

The downfall of Retinyl Palmitate was due to released reports about the ingredient being correlated to sun damage and skin tumors.

Most of this traces back to a 2012 US National Toxicology Program (NTP) study where hairless mice coated in Retinyl Palmitate cream and exposed to UV light developed skin tumors faster.

Here's the nuance, though.

When the Cosmetic Ingredient Review (CIR) Expert Panel went back through that study, they found methodological flaws and decided the results couldn't be interpreted as proof of extra risk.

The EU's Scientific Committee on Consumer Safety (SCCS) said the mouse findings might point to a concern but they're hard to apply to humans since hairless mouse skin and human skin behave differently.

While there is a study showing this ingredient to cause DNA damage when exposed to UVA, there is no concrete proof of it being linked to skin cancer. It is completely safe to use when used correctly.

Both the CIR and the SCCS consider it safe at the concentrations used in cosmetics; the SCCS specifically cleared retinoids up to 0.05% in body lotions and 0.3% in face creams, hand creams, and rinse-off products.

As of 2025, the EU has written those limits into law, plus a label warning about your total Vitamin A intake from all sources.

All retinoids increase your skin's sensitivity to the sun in the first few months of usage. Be especially careful with reapplying sunscreen when using any form of retinoid.

One more note: if you're pregnant, high doses of Vitamin A can be a concern, so a lot of people skip topical retinoids (including Retinyl Palmitate) during pregnancy just to be safe. Check with your doctor if you're unsure.

Fun fact: This ingredient is often added to low-fat milk to increase the levels of Vitamin A.

The DNA is extracted from several different animal sources, including: calf thymus, the gonadic tissue of a male sturgeon, or herring / salmon sperm.

You have probably seen this ingredient in anti-aging skincare. But what is it?

DNA is composed of nucleotides, or chemical building blocks. Nucleotides include adenine (A), thymine (T), guanine (G), and cytosine (C). Talk about a flashback to biology! Nucleosides are formed from these nucleotides.

The science behind Sodium DNA is based on an ingredient called Polydeoxyribonucleotide or PDRN.

PDRN are DNA fragments mainly extracted from the sperm cells of trout or salmon. Meaning, PDRN can be derived from Sodium DNA.

PDRN consists of chains of nucleotides and nucleosides mentioned above. They can range anywhere from 80 - 2000 pairs.

Studies show PDRN has the following properties:

Most of the research on PDRN has been done using injectable forms. That’s important, because PDRN is a large molecule and doesn’t absorb well through the skin. So if you’re applying it topically, the effects are likely to be much milder.

Still, topical Sodium DNA is emerging as a trendy anti-aging ingredient. It’s generally well-tolerated and offers good biocompatibility with human skin, making it a low-risk addition to most routines.

Further studies are needed to truly confirm this ingredients anti-aging ability (Remember, retinol has decades of research!).

Sodium DNA may be sourced from fish, animal tissue, or plants. Since this isn’t always disclosed, we recommend asking the brand directly if the ingredient’s origin is important to you.

Astaxanthin is also great at soothing skin due to its ability to block molecules that signal inflammation. It is currently being studied for preventing chronic inflammatory diseases.

Plus, a study from 2012 found Astaxanthin in liposomes protected mouse skin from UV-damage.

Fun fact: Astaxanthin is responsible for giving salmon a pink color.

Research also suggests that proteoglycans from sources like salmon nasal cartilage can "talk" to skin cells and encourage them to stay healthy by supporting the cells that maintain the skin's structure.

Other studies show proteoglycans may help skin recover from damage from things like UV exposure.

In lab and animal studies, NMN has demonstrated:

This ingredient also breaks down into niacinamide even as it degrades.

There are two major caveats to this ingredient:

1) It is not stable and degrades quickly in water-based formulations.
2) Most of the skin data is still prelinical (cell and animal studies) and human clinical trials are still limited.

Ceramides are an important building block for our skin barrier. A stronger barrier helps the skin look more firm and hydrated. By bolstering the skin ceramides act as a barrier against irritating ingredients. This can help with inflammation as well.

If you would like to eat ceramides, sweet potatoes contain a small amount.

Read more about other common types of ceramides here:
Ceramide AP
Ceramide EOP
Ceramide NP

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.

The skin's ability to produce ceramides gets disrupted in skin conditions like eczema. This in turn weakens the skin barrier and applying ceramides topically has been shown to replenish what's been lost to restore barrier function.

Most of the studies with Ceramide AP test it as part of a multi-ceramide complex; studies reinforce ceramide AP's role in rebalancing ceramides in skin and improving skin hydration.

Once on your skin, the enzyme alpha-glucosidase snips off the glucose and gradually releases active ascorbic acid right where it's needed. Basically, it behaves like a slow-release pro-vitamin C with less of a stinging that high-strength ascorbic acid can cause.

The research supports the classic vitamin C benefits as well. In lab and human studies, AA-2G slowed down the skin's production of melanin (the pigment behind dark spots) and helped shield skin cells against sun damage better than ascorbyl phosphate.

These studies also showed AA-2G released vitamin C over a longer period.

A frequently cited manufacturer trial found that a 2% AA-2G face cream significantly improved wrinkle depth and skin roughness after 45 days.

And in 2009, a clinical trial showed it meaningfully lightened dark patches on the gums compared to a placebo.

There's also collagen-synthesis support (since vitamin C is a required cofactor for that) and an antioxidant effect too.

Typical usage is usually between 0.5-5% and most studies/products land around 2%.

AA-2G performs best when formulated at a mildly acidic pH (~5-7) which is much gentler than the pH that pure vitamin C demands (~2.5-3.5).

Just one thing worth knowing: the in-skin conversation rate is only about 55-60% by weight. So a 5% AA-2G product delivers roughly 2.75-3% of actual active vitamin C. On top of that, skin absorption is relatively low because the ingredient is water-soluble.

It helps with dark spot fading by interfering with the process of skin darkening, helping to reduce hyperpigmentation. Like other forms of vitamin C, this ingredient encourages the skin to create more collagen.

As an antioxidant, it helps fight free-radicals. Free-radicals are molecules that may damage your skin cells.

One study found Ascorbyl Tetraisopalmitate to degrade in sunlight, but is stabilized when combined with acetyl zingerone.

In a formula, it does the 3 classic vitamin C jobs: it acts as an antioxidant, helps brighten skin tone by inhibiting tyrosinase, and supports collagen.

The evidence is reasonably solid for a cosmetic ingredient; Liao and colleagues (2018) showed it's significantly more stable than ascorbic acid while still being effective.

A 2021 study by Zerbinati and colleagues tested a serum with 30% 3-O-ethyl-l-ascorbic acid and 1% lactic acid significantly increased collagen production, reduced UVB-induced DNA damage, and decreased melanin on a reconstructed pigmented skin model.

Typical real world usage sits around 0.5-5% (and 1-2% is common for daily serums).

Amounts up to 30% have been shown to be non-irritating on human skin samples, but two isolated cases reported allergic contact dermatitis so a patch test is sensible if you have reactive skin.

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.

In Chinese traditional folk medicine, Scutellaria Baicalensis Root Extract is used to help treat lung issues and hypertension.

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).

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.

The root of the plant has been used in traditional folk medicine throughout Asia.

Antioxidant components in chamomile make it an effective ingredient to help slow the signs of aging. Antioxidants help fight free-radical molecules, or molecules that may damage your skin.

Essential oils from chamomile have been found to improve wound healing due to its antimicrobial properties.

Ancient Greeks and Egyptians used Chamomile to treat skin redness and dryness. Chamomile has also been used to help treat stomach issues.

These compounds protect your skin two ways:

1) They fight off free radicals, or the unstable molecules from things like sun and pollution that age and damage skin.
2) They help calm inflammation by switching off the chemical signals that tell skin to get red and irritated.

Lab studies also suggest that rosmarinic acid may help protect collagen and slow sugar-related damage to it.

The Cosmetic Ingredient Review has concluded rosemary-derived ingredients to be safe when formulated to be non-sensitizing.

Rosemary can occasionally cause allergic contact dermatitis (due to carnosol), so be sure to patch test if you have reactive or fragrance-sensitive skin.

Compared to rutin, glucosylrutin is more stable and easier to formulate into water-based products (it's water soluble).

This ingredient is an emollient, emulsifier, and penetration enhancer. As an emollient, it helps soften and hydrate skin by trapping moisture within. As an emulsifier, it prevents oil and water ingredients from separating.

Hydrogenated Lecithin can form tiny spherical structures made of phospholipid bilayers called liposomes. These liposomes are able to capture compounds inside their structure and deliver them through the skin barrier.

Because phospholipids are a natural component of our cell membranes, this ingredient is inherently compatible with skin.

A 2021 study found lecithin-based surfactants were less harsh and more tolerable comared to Sodium Lauryl Sulfate (SLS).

It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.

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

In practice, that translates to a long shelf life and a consistently elegant skin feel.

While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.

Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.

This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.

This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Read more about some other popular AHA's here:

They work by fitting perfectly into your stratum corneum's lipid matrix since they're structurally similar to cholesterol. Here, they reinforce your skin's barrier.

One small in vivo human study showed topical soybean phytosterols sped up barrier recovery within three days on tape-stripped skin.

Broader research credits them with:

Formulation use typically sit under 5%.

Testing in soy-allergic subjects found no sensitization signals, but be sure to patch test if you are unsure or have existing allergies.

Basically, Peg-60 Hydrogenated Castor Oil helps hold ingredients together.

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.

Here's an interesting thing about Arginine: your skin converts it into urea through the Krebs-Henseleit urea cycle. Urea is one of the most effective humectants your skin naturally produces.

A clinical study showed applying 2.5% arginine hydrochloride to atopic dermatitis skin showed significant urea levels in the stratum corneum and improved moisture in just four weeks.

Arginine is also a precursor to nitric oxide; nitric oxide improves microcirculation and supports wound healing and collagen synthesis.

One study found that an amino acid complex containing Arginine reduced skin irritation, improved hydration, and accelerated skin repair in clinical / in-vivo studies.

Arginine itself is an amino acid and not a fatty acid, oil, or ester. On its own, it's not a direct food source for Malassezia, or the yeast that causes fungal acne.

The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).

Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

As a preservative, it is used to stabilize products and prevent them from degrading. Specifically, BHT prevents degradation from oxidation.

The concerns related to BHT come from oral studies; this ingredient is currently allowed for use by both the FDA and EU.

However, it was recently restricted for use in the UK as of April 2024.

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

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%.

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.