Origins Plantscription Multi-Powered Youth Serum Versus Origins Mega-Mushroom Relief & Resilience Advanced Face Serum

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.

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

Like other essential oils, this ingredient can be a fragrance allergen.

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)-

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.

When exposed to air, these two compounds become strong allergens. This ingredient exhibits cytotoxicity at low concentrations; amounts of 0.25% have been shown to damage skin cells.

A study from Japan found this ingredient caused lavender sensitivity after widespread exposure.

Lavender essential oil has some antimicrobial, antibacterial, and anti-inflammatory properties. However, the cons of this ingredient may outweight the pros.

More research is needed to confirm lavender essential oil's effects when used in aromatherapy.

Lavandula Angustifolia is known as the English Lavender and famous for creating purple fields in Provence, France.

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.

The scent of Rose Geranium closely resembles traditional roses.

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.

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.

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.

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!

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.