Crawford Street Skin Care Restorative Facial Oil

Another interesting compound that makes it stand out from other oils is the trace amount of all-trans retinoic acid (the same molecule as prescription tretinoin), along with some carotenoids and tocopherols.

The linoleic acid is a precursor to ceramide 1, one of the essential lipids in the stratum corneum. Topical linoleic acid application has been shown to improve barrier function and reduce comedone size in clinical studies.

One study found that linoleic acid and alpha-linoleic acid lighten UV-induced hyperpigmentation. A 2015 study found that participants who used rosehip twice daily for eight weeks saw improvements in crow's feet, skin moisture, and skin elasticity compared to the placebo.

If you're hoping to get tretinoin benefits from this ingredient, it's worth noting the trans-retinoid acid is trace-level and minimal compared to the amount of retinol or tretinoin found in formulas.

A 2024 review highlighted the fatty acid composition in rosehip-based dermatological products for:

Typical usage rates range from 1-100% with 5-10% being the most common in moisturizers.

Since the oil is high in polyunsaturated fatty acids, it's prone to oxidation. Look for formulations stabilized with ingredients like vitamin E and be sure to store away from light/heat.

Fungal acne: This oil is not considered fungal acne safe because dominant fatty acids fall into the C11-24 range that Malassezia can metabolize.

Two clinical studies in postmenopausal women found that applying argan oil for 60 days significantly improved skin elasticity and moisturization (reduced transepidermal water loss and increased epidermal water content).

Since it is high in oleic and linoleic acid, this ingredient may not be fungal acne safe. Both of these fall in the C11-C24 range that Malassezia yeast can metabolize.

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

It has been used in traditional Indian Ayurvedic medicine for centuries.

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.

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.

In cosmetics, its job is mostly sensory: it has a sweet, floral scent often used in perfume.

Chemically, it's complex mix of fragrant molecules: geraniol, limonene, linalool and benzyl benzoate.

Several of these components are on the EU's list of recognized fragrance allergens; this means they have to be labeled when present above 0.001% in leave-on products and 0.01% in rinse-off products.

This ingredient is a known contact sensitizer for a small amount of people so it's definitely worth patch-testing if your skin is reactive.

Lab studies have found the oils does have real antioxidant and antibacterial activity, but keep in mind these are in-vitro findings rather than proven skincare benefits.

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.