YSE Beauty Last Call Retinol Serum

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.

Caprylic Triglyceride is made by combining glycerin with coconut oil, forming a clear liquid.

While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this.

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.

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

Studies show Cetearyl alcohol is non-toxic and non-irritating. The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient is usually derived from plant oils such as palm, vegetable, or coconut oils. There is debate on whether this ingredient will cause acne.

Due to the fatty acid base, this ingredient may not be Malassezia folliculitis safe.

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.

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

Sodium Hyaluronate is naturally occurring in our bodies and is mostly found in eye fluid and joints.

These are some other common types of Hyaluronic Acid:

As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.

Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.

Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.

In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.

This ingredient is organic, colorless, odorless, and non-toxic.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

These fatty acids help the skin create ceramides. Ceramides play a role in repairing the skin barrier.

Helianthus Annuus Seed Oil helps moisturize the skin. This in turn helps the skin look more rejuvenated and smoother.

Sunflowers are rich in vitamin E.

Historians believe Indigenous cultures of North America domesticated sunflowers before corn. Thus they relied on sunflower oil for a variety of uses. One such use is moisturizing skin and hair.

Sunflower seed oil may not be fungal acne safe. We recommend speaking with a professional if you have any concerns.

According to a manufacturer, it helps create a "smooth, light and fresh" texture.

This ingredient can be derived from palm oil, or coconut oil. It is also naturally found in certain species of organisms.

According to the NOAA, this ingredient can cause skin sensitivity with prolonged use. However, this warning is taken from the Coast Guard and no studies have been done on this in relation to cosmetics.

Tridecane is not water soluble.

If you spot Citric Acid near the end of an ingredient list, it's likely there as a pH adjuster rather than an active ingredient.

Read more about some other popular AHA's here:

As an emollient, it helps soften skin and supports barrier-replenishing ingredients.

In cosmetics, Glyceryl Stearate is often made from vegetable oils or synthetically produced.

This ingredient may not be fungal-acne safe

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

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.

This ingredient is typically found in concentrations between 0.5-1%. It is usually created synthetically or from rice bran oil.

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

Linoleic acid is an essential fatty acid, meaning our bodies cannot create it on its own. We need to get linoleic acid through foods such as nuts and vegetable oils.

Acne-prone skin tends to have linoleic acid and high levels of oleic acid.

Linoleic acid 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.

This ingredient 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.

Linoleic acid is not always fungal-acne safe; it may trigger flare-ups in sensitive individuals.

Due to their hygroscopic nature, they act as both humectants and emollients. Humectants draw moisture from the air to your skin, while emollients help trap moisture in.

The phospholipids in our skin can be naturally depleted. Replenishing the phospholipids in our skin can help hydrate your skin.

Studies show phospholipids display antioxidant activity and may help with reducing the signs of aging.

This ingredient is non-occlusive.

Some types of phospholipids:

Specifically, AHAs work by breaking down the structural "glue" holding the old skin cells in place. Getting rid of the old skin cells allows skin to regenerate newer skin cells in its place. A build up of dead skin cells can lead to tired and dull looking skin.

Due to this, glycolic acid helps with:

Fun fact: Glycolic acid increases skin hydration by playing a role in creating molecules that create hyaluronic acid naturally.

When starting glycolic Acid, it is normal to feel slight stinging.

The pH value and concentration of glycolic acid play a role in the effectiveness of the product. Concentrations between 5-20% glycolic acid have been shown to be effective in clinical studies.

Recent studies have shown Glycolic Acid may protect the skin against UV damage. However, you should always wear SPF, especially when using exfoliants.

Read more about some other popular AHA's here:

However, alcohol denat. is not all that bad.

Due to its low molecular weight, alcohol denat. tends to evaporate quickly. One study on pig skin found half of applied alcohol evaporated in 10 seconds and less than 3% stayed on skin.

This also helps other ingredients become better absorbed upon application.

Studies are conflicted about whether this ingredient causes skin dehydration. One study from 2005 found adding emollients to propanol-based sanitizer decreased skin dryness and irritation. Another study found irritation only occurs if your skin is already damaged.

Small amounts of alcohol are generally tolerated by oily skin or people who live in humid environments.

The rule of thumb is if this alcohol is near the end of an ingredients list, it will probably not affect your skin much.

Also...

This ingredient has antimicrobial and solvent properties.

The antimicrobial property helps preserve products and increase their shelf life. As a solvent, it helps dissolve other ingredients.

Other types of astringent alcohols include:

Though Caprylyl Glycol is an alcohol derived from fatty acids, it is not the kind that can dry out skin.

This ingredient is also used as a preservative to extend the life of products. It has slight antimicrobial properties.

Fun fact: This wax has the highest melting point of all natural waxes and low solubility.

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

Another benefit is a bit of UV protection. Vitamin E helps reduce the damage caused by UVB rays. (It should not replace your sunscreen). Combining it with Vitamin C can decrease sunburned cells and hyperpigmentation after UV exposure.

You might have noticed Vitamin E + C often paired together. This is because it is great at stabilizing Vitamin C. Using the two together helps increase the effectiveness of both ingredients.

There are often claims that Vitamin E can reduce/prevent scarring, but these claims haven't been confirmed by scientific research.

This ingredient is often used to enhance the texture of products. The fatty acid properties also help hydrate the skin.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

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.

As an emulsifier, Hexylene Glycol helps keep water and oil together. This prevents them from separating in a product. Hexylene Glycol also thins out the texture of a product by lessening viscosity.

Hexylene Glycol has a small molecular weight.

Polysorbate 20 also adds scent to a product. Since it is made using sorbitol, it has a sweet scent. Sorbitol can also be found in fruits such as apples and peaches.

The lauric acid used to create Polysorbate 20 is often derived from coconuts.

Polysorbate 20 may not be fungal acne safe.