Rationale #6 The Night Crème

Its similarity to our skin's natural oils makes it a great emollient. Emollients help soften and soothe our skin by creating a barrier on top. This barrier helps trap moisture in, keeping skin hydrated.

It is created using either the hydrogenation or transesterification processes on jojoba oil.

Due to regulation loopholes, you'll likely see this ingredient in "100% mineral" sunscreens.

This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.

Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.

Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.

Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.

This ingredient improves spreadability and helps thicken a product.

According to manufacturers, it usually comes from vegetable-based saturated fatty acids. Common bases for this ingredient are coconut oil, palm kernel oil, or both.

Due to the melting point being close to skin temperature, it is usually used in lip products.

Triglycerides are a main component of fat in the human body.

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.

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.

A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.

In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.

You'll likely see use concentrations quite low, usually 0.1-0.2%.

Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.

Your body uses linoleic acid to build ceramides and prostaglandins. Ceramides keep your skin's barrier hydrated and strong while prosaglandins help control inflammation and healing.

Needless to say, linoleic acid is crucial for having a strong skin barrier.

One study found applying linoleic acid rich sunflower oil to be more effective at repairing the skin barrier than olive oil.

This ingredient can also help treat acne by softening sebum to prevent clogged pores. Another study found using 2.5% linoleic acid gel for 4 weeks showed a 25% reduction in small comedones.

Studies show it can also help lighten hyperpigmentation or sun spots by disrupting the melanin production process. It also helps your skin shed melanin pigment from your skin caused by UV exposure.

Due to its role in the production of the fatty acid prostaglandin, linoleic acid can also help reduce inflammation and support wound healing.

Fun fact: Linoleic acid is an essential fatty acid. This means our bodies cannot create it on its own and we need to get it through foods such as nuts and vegetable oils.

Just know this ingredient is not always fungal-acne safe because it is a long-chain fatty acid (with 18 carbon atoms) that directly feeds the Malassezia yeast responsible for fungal acne.

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.

This ingredient is considered gentle and non-comedogenic. However, it may still be irritating for some.

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.

One in-vitro study found that this ingredient tells your skin cells to produce more of the proteins (filaggrin, loricrin, and involucrin) for building a strong and healthy barrier. This study also found this ingredient to be a solid antioxidant that helped neutralize damage against UV and pollution.

A study with people from 2010 found that sensitive, reactive skin using a cream with 10% of this ingredient for a month became noticeably less dry, less reactive, and harder to irritate compared to the group using a plain cream.

In short, this ingredient is a well-tolerated ingredient that can help with barrier repair, antioxidant protection, and calming reactive skin.

This ingredient is generally considered fungal acne (Malassezia) safe; Bifidobacterium is a bacterium, not a yeast or fungus.

The fungal acne concern with fermented ingredients mainly applies to yeast-derived ferments like Saccharomyces and Galactomyces, because those are in the same kingdom as Malassezia and could theoretically contain residual compounds that feed it.

Bifida is a completely different organism, so on its own it doesn't provide a food source for the Malassezia yeast that causes fungal acne.

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.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

It has the most scientific studies backing up its skin benefits out of all the non-prescription ingredients.

Retinol is proven to:

This is why retinol is effective at removing wrinkles, fading dark spots, treating acne, and reducing the appearance of pores.

Studies show retinol is less effective when exposed to UV. Be sure to look for appropriate packaging to keep your retinol potent (similar to Vitamin C).

Using retinol or any retinoids will increase sun-sensitivity in the first few months. Though studies show retinoids increase your skin's natural SPF with continuous use, it is best to always wear sunscreen and sun-protection.

We recommend speaking with a medical professional about using this ingredient during pregnancy.

Retinol may cause irritation in some people, so be sure to patch test. Experts recommend 'ramping up' retinol use: start using this ingredient once a week and work up to using it daily.

Read about Tretinoin

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

This ingredient is often coated with metal oxides like titanium dioxide. Trace amounts of heavy metals may be found in mica, but these metals are not harmful in our personal products.

Mica has been used since prehistoric times throughout the world. Ancient Egyptian, Indian, Greek, Roman, Aztec, and Chinese civilizations have used mica.

Some studies suggest betaine may support making skin tone more even.

Fun fact: Betaine naturally exists in the skin and the body. In cosmetic products, it can be either plant-derived (most commonly from sugar beets) or synthetically produced for consistency and stability.

Betaine is also known as trimethylglycine.

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%.

Fun fact: This ingredient is also used to mask the bitter taste of medicine.

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.

The fatty acids found in sunflowers include (from highest amount to least): linoleic acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, and linolenic acid.

These fatty acids hydrate your skin. Emollients create a film on the skin to prevent moisture from escaping.

This ingredient is biodegradable and commonly available in natural/COSMOS-certified grades.

Caprylhydroxamic Acid is often used with natural antimicrobial products as an alternative to preservatives.

Citrus peels are often made up of mainly limonene, a fragrance with a citrus scent. They also contain flavonoids, which have anti-inflammatory properties.

In this case, the 60 comes from reacting 60 units of ethylene oxide with sorbitan.

Polysorbates are commonly used in medicine and foods.

In a 24 hour occlusive patch test on 56 subjects, 10% sorbitan isostearate was completely non-irritating. Most formulas use less than 10%.

Because it's a fatty acid ester, it may not be fungal acne safe since the Malassezia yeast can utilize it as a nutrient source.

Studies show retinal may work at a faster rate than retinol due to its structure.

All retinoids have to be converted into retinoic acid before starting to work. Some retinoids take several steps of conversion before binding. Retinal is only one step away, making it more potent.

Like other retinoids, retinal may be irritating. It is best to ease into using this ingredient frequently.

Using the 'ramp up' method, start by using retinol once a week. This gives your skin time to adjust and decrease irritation. Once you feel ready, you can slowly increase the frequency of retinol use.

Using retinoids will increase sun-sensitivity in the first few weeks of use. Though studies show retinoids increase your skin's natural SPF with continuous use, it is best to always wear sunscreen and sun-protection.

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.

Another name for this ingredient is Texas Cedarwood oil.

The scent of Rose Geranium closely resembles. you guessed it: roses.

This ingredient is a known EU allergen. In the European Union, regulation mandates some fragrance allergens must be labeled so consumers who are sensitive to them can make informed choices.

It is considered non-irritating on the skin.

Like cetearyl alcohol, Ceteareth-25 can help thicken and create a gel-like consistency.

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.

When used topically, Citrus Aurantium Bergamia Fruit Oil is a photosensitizer due to the furanocoumarin content. Furanocoumarins absorb UV-A and cause phytophotodermatitis; this can look like redness, blistering, and lasting brown pigmentation on sun-exposed skin.

Due to this, this ingredient is capped at 0.4% in leave-on products applied to sun exposed skin.

Many modern formulas used a "furanocoumarin-free" version that sidesteps the phototoxicity issue, but still contains the fragrance allergens.

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

Most reputable companies will remove furanocoumarins from their formulations.

Citral has documented antimicrobial activity against acne bacteria (which is where the marketing claims about it being good for acne-prone skin originate), but real formulas use it at fragrance-level concentrations under 1%.

The main thing worth knowing is that citral is a known EU fragrance allergen so people with known fragrance sensitivities may want to skip it.

Unlike citrus oils, May Chang doesn't contain furocoumarins and therefore isn't phototoxic.

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.

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

ALA is a great skin hydrator because it has the ability to restore lipids in our stratum corneum, or outermost layer of our skin; it also helps prevent transepidermal water loss.

This ingredient also helps soothe irritated skin by downregulating inflammation.

Chia seed oil is one of the highest natural sources of ALA. Research shows topical chia seed oil significantly improves skin hydration, reduces itch, and strengthens the barrier in both healthy and extremely dry skin.

Additionally, in-vivo and in-vitro studies show ALA exhibits antioxidant properties, reduces UV-induced inflammation, and supports wound healing.

Early research showed a fatty-acid deficiency in animals leads to abnormal skin barrier function. It is believed a deficiency in linolenic acid may be linked to skin disorders like eczema.

Fun fact: This ingredient is considered an essential fatty acid for humans. This means our bodies cannot naturally produce it and we must get it from food. Some foods rich in linolenic acid include walnuts, fish oils, soy, and canola.

Though it has "alcohol" in the name, it is not related to denatured alcohol or ethyl alcohol.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient may not be fungal acne safe. It is a primary fatty alcohol with a chain length above 12 carbons. A study from 2019 show Malassezia can feed on fatty alcohols in this range, so it may trigger fungal acne in those prone to it.

This ingredient is derived from isobutane. It is the simplest form of a tertiary alcohol. Due to its chemical structure, it is more resistant to oxidation.

Some sources online claim T-Butyl Alcohol is a fatty alcohol. However, it is not considered one due to its chemical structure.

It is only considered a carcinogen when ingested.

Butylated Hydroxyanisole is a synthetic and waxy petrochemical. It is used as a preservative in foods and cosmetics.

Having moisturized skin helps improve the skin barrier. Your skin barrier helps protect against irritants and bacteria.

It's worth knowing sugars are already a natural component of the skin's NMF (natural moisturizing factor) so it's a molecule that your stratum corneum is well-acquainted with.

Just so you know, glucose is hydrophilic (water-loving) and the stratum corneum is a strong barrier to hydrophilic compounds. This just means penetration is slow and most of the action is happening on the surface.

Gram-to-gram, glucose is not as efficient as a humectant as glycerin. This is why you'll likely see glycose paired with stronger humectants for a bigger hydration payoff.

In skincare, glucose is typically derived from corn or other starch sources.

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.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

On skin, it forms a protective, emollient layer that helps with moisture retention and contributes to barrier integrity.

In vitro studies on genotoxicity have come back negative and this ingredient is well-tolerated. Typical use concentrations range from 0.024%-22%.

This ingredient may not be fungal acne safe because Behenic acid falls within the C11-24 fatty acid range capable of supporting Malassezia growth.

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.

This is a great ingredient for dry, compromised, or aging skin; our skin starts to produce less cholesterol with age.

Research shows cholesterol works best in combination with ceramides and fatty acids, the other two major components in your skin barrier.

Cholesterol is also a well-establish penetration enhancer and can help other actives absorb more effectively.

Cosmetic-grade cholesterol is usually derived from lanolin but plant and synthetic options also exist. We recommend reaching out to the brand if you have questions about their source of cholesterol.

Copper has wound healing properties due to its role in creating new blood vessels and tissue repair.

Studies show conditions like atopic dermatitis can worsen when ceramide NS levels are low.

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:

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.

Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.

An in-vitro study from 2024 found glutamic acid to play a role in inhibiting inflammation and thus a potential skin-soothing ingredient.

Other studies show it to be have potential wound healing, skin barrier repair, and hair growth properties.

Glutamic acid has poor solubility in water and other solvents.

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.

EOP stands for a linked Ester fatty acid, a linked Omega hydroxy fatty acid, and the Phytosphingosine base.

What makes Ceramide EOP special is its ultra-long fatty acid chain; this unique structure allows it to bridge the lipid layers in your skin barrier to prevent water loss (something no other ceramide can do).

Low levels of Ceramide EOP have been found in people with eczema and psoriasis.

Using it together with other ceramides, cholesterol, and linoleic acid have been shown to meaningfully improve hydration and reduce water loss.

In one clinical study, a regimen using Ceramide EOP, NP, and AP led to significant symptom improvements in patients with eczema, psoriasis, and dry skin in just 4 weeks.

You'll usually see concentrations between 0.1-0.5% in formulations. Overall, this is a well-tolerated and safe ingredient for cosmetic use.

Ceramide EOS is a synthetic N-acylated sphingolipid consisting of Sphingosine having the D-erythro structure linked to an esterified omega-hydroxy saturated or unsaturated fatty acid

Ceramides work to improve hydration from within. Their lipophilic trait means they are likely to be absorbed into skin but expected to remain in the epidermis (the outer layer of skin).

In skincare, lysine is mostly there to help keep your skin moisturized. It carries water through your skin's layers so everything stays plump.

So will putting lysine on your face create bouncier skin?

It's hard to say; most of the exciting collagen research on lysine comes from oral supplements or lab studies on mice. Further research is needed to truly understand what role topical lysine plays in skincare and your skin.

However, there's no harm in adding lysine to your routine as a supportive and hydrating ingredient.

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.

Two structures of phenylalanine exist: L-phenylalanine and D-phenylalanine. L-phenylalanine is essential, this means our bodies cannot produce it naturally and we must get it from foods. Our bodies convert D-phenylalanine to neurotransmitters, and D-phenylalanine is found in our bodies naturally.

Some foods that contain L-phenylalanine include eggs, soybeans, beef, milk.

Reviews of this ingredient have found it to be neither a dermal irritant nor a sensitizer.

Fun fact: Proline can be found in protein-rich foods like meat, fish, eggs, and dairy.

This ingredient can either be derived from an animal product or be synthetically created.

One study found histidine and carnosine to be a dynamic duo for your skin:

Oral histidine has also been found to help with filaggrin-deficit skin disorders such as atopic dermatitis.

Why is it considered a semi-essential amino acid? This is because adults are able to create it but children must get it from their diet.

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.

Limonene acts as an antioxidant, meaning it helps neutralize free radicals.

When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin.

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.

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.

This ingredient has a scent that is floral, spicy tropical, and citrus-like.

Citronellol is a modified terpene. Terpenes are unsaturated hydrocarbons found in plants. They make up the primary part of essential oils.

Citronellol is not able to be absorbed into deeper layers of the skin. It has low permeability,

Citronellol is also a natural insect repellent.

Ci 77891 is commonly found in sunscreens due to its ability to block UV rays.

Synthetically created Ci 77491 is considered safer than those naturally found. This is because the synthetically created version may contain less impurities. Iron oxides are generally non-toxic and non-allergenic.