Kiehl’s Midnight Recovery Concentrate Review

Capric Triglyceride or Caprylic/Capric Triglyceride (CCT) is an emollient ester that was deemed as a safe ingredient to use in products per a safety assessment conducted in 1980 per the CIR panel.

Well, it’s been quite some time since 1980. And I am willing to bet that there have been cases reported and studies performed relative to this particular ingredient. In fact, most recently in 2017, the same CIR safety panel decided to re-evaluate and assess caprylic/capric triglyceride based on current clinical and animal data. And although the verdict isn’t necessarily in, I would be willing to bet the final assessment will deem this product safe as the origins of this ingredient come from benign oils.

Back to CCT (or sometimes known as caprylic acid) is a specific fraction of coconut/palm oil fatty acids – resulting in a stable form of esters. But how is this ingredient relevant to me?!

First, caprylic acid has been found and studied to have superior medical potential in anti-cancer, anti-Alzheimer’s, anti-Autism, and providing general circulatory improvement. But it also has potential beneficial applications as an anti-aging ingredient. Yessss!

Bottom line: Emollient ingredient derived from coconut and palm oil. Known for its skin-conditioning and anti-aging capabilities.

Dicaprylyl carbonate is the diester of carbonic acid and caprylyl alcohol.  Dicaprylyl carbonate functions as a solvent and skin-conditioning agent in cosmetic products.

I reviewed the CIR and found minimal information with respect to this compound.  There were a few irritation studies within the CIR review which concluded dicaprylyl carbonate to be safe and non-irritating based on the specific use and concentration within the cosmetics.

The closest I could find was the following trademarked compound and its benefits as listed on the vendor’s websites:

• BASF Cetiol® CC/MB
  • “Good performance of solubilizing crystalline UV filters”

Bottom line: Not much can be said about dicaprylyl carbonate other than that it functions as a solvent and skin-conditioning agent in cosmetics.

Squalane is the hydrogenated/saturated derivative of squalene. Squalene is an organic compound often derived from amaranth seed, fish oils, wheat germ, and most importantly – olives. In fact, human sebum also contains 13% squalene as one of its major constituents – offering protection to skin’s lipids as natural sun blockers – at high levels. How interesting!

Various studies evaluated both squalane and squalene for its anticancer, antioxidant, skin hydrating and emollient activities in both animal models and in vitro environments. And at specific concentrations used in moisturizers, squalane has been shown to have little effect in terms of irritation relative to skin permeability.

And of the two – squalane is the least susceptible to oxidation compared to its squalene derivative.

Bottom line: Strong antioxidant, skin hydrating, and emollient agent. Natural sun-blockers!

Rosa canina (rosehip) has long been used for its medicinal properties and often functions as a skin conditioning agent, fragrance ingredient, astringent, anti-acne agent, humectant, and exfoliant in cosmetic products. 

The results of a fatty acid analysis indicated that Rosa canina contains the following most abundant fatty acids: linoleic acid (35.9–54.8%), α-linolenic acid (16.6–26.5%), and oleic acid (14.7–22.1%).  These essential fatty acids are the precursors for omega-3 (linolenic acid and linoleic), 6 (linoleic), and 9 (oleic) which have been shown to in studies to improve skin hydration and elasticity.  And studies have concluded that fatty acids (such as linolenic acid) contained in a majority of these oils create a film on the skin which reduces transepidermal water loss (TEWL), thus contributing to maintaining the correct hydration of the epidermis.   

The rosa canina seeds and shells also contain high amounts of carotenoids (precursors of vitamin A and high amount of vitamin E).  Many studies have pointed to such vitamins to support skin maintenance – with Vitamin A stimulating the cells of the skin, restoring damaged skin cells and therefore, making a brilliant anti-aging ingredient.

With its high composition of fatty acids and antioxidants, this oil has relatively high protection against inflammation and oxidative stress.

Bottom line:   Rosa canina functions as a skin conditioning agent, fragrance ingredient, astringent, anti-acne agent, humectant, and exfoliant in cosmetic products.  Due to its high essential fatty acid content, Vitamin A and Vitamin E content – it often provides anti-inflammatory and antioxidant capabilities. It has also been shown to improve skin hydration and elasticity.

Oenothera biennis (evening primrose) is a plant that initially begins its life infertile but then produces bright yellow flowers (in its second year of life); with seeds containing up to 25% of fatty acids in its chemical composition.  The triglycerides of the fatty acids are mainly linolenic (8-10%) and linoleic acid (70-74%), which may contribute to the proper functioning of human tissues because they are precursors of anti-inflammatory eicosanoids.  In addition to the fatty acids, evening primrose contains phenolic acids and flavonoids.

And it is believed that the source of these biologically active compounds originates from the seeds and; above all, evening primrose seed oil.   

Evening primrose oil is often administered internally in treatment and alleviation of symptoms of atopic dermatitis and varying skin issues.  Evening primrose oil is also known to improve skin moisture and transepidermal water loss (TEWL) due to its fatty acid composition. In fact, there are several studies evaluating the systematic improvements of the skin using evening primrose oil.  These studies may include (but are not limited to) the following:

• A 2002 study evaluated the therapeutic effect of evening primrose oil in atopic dermatitis patients with dry scaly skin lesions.  The study concluded that evening primrose oil was highly effective in the treatment of a non-inflammatory type of atopic dermatitis.
• A 2005 study which performed a randomized, double-blind, placebo-controlled study in healthy adults testing evening primrose oil on skin moisture, TEWL, redness, firmness, elasticity, fatigue resistance and roughness.  With the exception of skin redness, all measured variables were significantly different in the evening primrose oil group compared with placebo. Improvements of skin moisture (12.9%), TEWL (7.7%), elasticity (4.7%), firmness (16.7%), fatigue resistance (14.2%), and roughness (21.7%) were observed compared to placebo.
• A 2014 study evaluated the clinical efficacy and safety of evening primrose oil in preventing cheilitis (skin inflammation and redness) in the lips of 40 acne patients.  The 8-week study concluded that evening primrose oil was found to induce an improvement in the cutaneous barrier function of the lips in acne patients as reflected in their TEWL.

Bottom line: Oenothera biennis (evening primrose) oil helps in the improvement of skin moisture, TEWL, elasticity, firmness, roughness, and fatigue resistance.

The name of this has always made me laugh. In fact, a childhood friend of mine and I would always chuckle at the sound of this ingredient in products. Was it “ho-ho-ba” or was it “joe-joe-ba”? Either way, you pronounce it – it’s a functional vehicle for providing natural hydration, moisturizing, and firming capabilities synergistically with other key extracts and essential oils. A number of reviews from scientific literature suggest that jojoba has anti-inflammatory effects and can be used on a variety of skin conditions including skin infections, skin aging, as well as wound healing.

In fact, a 2010 study assessed the hydration and viscoelastic effect of moisturizers containing different herbal ingredients (including jojoba oil) – after 3 weeks of topical application to the skin. The study found that there was a significant increase in skin viscoelasticity (90-95%) and increase in water content of the stratum corneum (upper layer of the skin) by 60-70%.

Bottom line: This funny sounding oil enhances the penetration of whatever is synergistically formulated into the product. It also provides hydration and promotion of skin elasticity!

Coriandrum sativum (coriander) seed oil is most known for its use in seasoning in food preparation but did you know that it also has applications as an antioxidant (and here), antimicrobial (and here), and antifungal?  

Well, now you do!

Coriander has been used as a herbal medicine for the treatment of diabetes, hyperlipidemia, liver disease, and cancer.  In fact, a 2014 study examined whether coriander extract had protective effects against ultraviolet B (UVB)-induced skin photoaging in normal human dermal fibroblasts (NHDF) in vitro and in the skin of hairless mice in vivo.  The study concluded that coriander extract decreased UVB-induced matrix metalloproteinase-1 (MMP-1) expression and stimulated procollagen type I production in vitro.  MMP-1 are enzymes that play a role in various destructive processes such as inflammation, tumor invasion, and skin aging.  In addition, coriander extract helped in preventing degradation of collagen and elastin fiber in vivo.

Bottom line: Coriander seed oil functions as a good antioxidant, antimicrobial, antifungal, and may assist in signs of photoaging.

Tocopherol is the most prevalent form of vitamin E in plant seeds and products derived from corn, sesame seed, sunflower, olive oils, and a plethora of nuts.

Most of the tocopherols are reported to function in cosmetics as antioxidants or skin conditioning agents.  In fact, a 2003 study, evaluated whether the combination of topical vitamin C and E was better for UV protection to the skin than an equivalent concentration of each – alone. The study concluded that each (in their own right) were significant antioxidants in the protection from skin damage. However, the combination of both C and E provided superior synergy against the likes of skin cancer and photo-aging. Further detailed information regarding tocopherol as a major lipid-soluble chain-breaking antioxidant of membranes and an important cellular protectant against oxidative damage was provided in a 2014 CIR safety assessment.

It is also interesting to note that in 1999, a study found that topical vitamin E applied on scars provided no benefit (in 90% of the cases) to the cosmetic outcome of scars after skin surgery.  And it even noticed that 33% of the patients treated, developed contact dermatitis to the vitamin E.

Overall, tocopherol is the predominant form of vitamin E in human and animal tissues, and it has a high bioavailability. The CIR safety assessment recognized that tocopherol has some absorption in the UV range. However, it was noted that according to animal and clinical testing, tocopheryl acetate was not photo-allergenic or phototoxic.

Bottom line: Strong antioxidant capacity. Best if formulated with Vitamin C ingredients but may be a potential for dermatitis.

Lavandula Angustifolia (also known as English lavender) oil is traditionally used as an antiseptic and medicinal agent, and now predominantly used as a relaxant – providing as a form of sedative and neurological treatment through aromatherapy.

With the beauty and health industry morphing — more and more products are being formulated with essential oils.   You quite literally can’t walk by a beauty counter or drug store without seeing a product marketed with the promise of lavender oil’s therapeutic benefits – such as its antioxidant and anti-inflammatory properties and its use in fighting several skin diseases. Lavender oil is rich in antioxidants (e.g. terpenoids, lactones and phenolic compounds) and is composed of the following main molecules: linalool (34-47%), linalyl acetate (17-34%), camphor (4-9%) and eucalyptol (3-7%) as determined from a 2016 study.

For a while, most of the research surrounding the benefits of lavender oil applied topically wasn’t the most compelling. However, a 2016 study recently evaluated lavender oil and its wound healing effect. The study concluded that topical application of lavender oil promoted collagen synthesis and up-regulation of TGF-β (needed for wound contraction).

This accelerated formation of tissue and collagen could be a game changer! The possibilities could be endless!

Bottom line: Lavender oil provides a natural aromatic fragrance that calms the mind and body. But the oil is composed of molecular components that prove quite beneficial as an antioxidant and anti-inflammatory agent; with new research unraveling possibilities for collagen synthesis!

Where would aromatherapy be without the smell of the rose? For centuries, humans have studied every aspect of this plentiful flower. The rose and its petals are often a symbol of love.

Geranium rose, which belongs to the Geraniaceae family, has been widely used for its antibacterial, anti-inflammatory, antifungal, and antioxidant properties – and is composed of various chemical constituents such as linalool (4.52%), citronellol (29.13%)l, and geraniol (12.62%).

Interesting enough, the geranium rose is actually a plant-based insect repellent.  

What?!  Did you guys know that?  

In fact, a 2004 study, evaluated mosquito repellents containing traditional DEET (N,N-Diethyl-meta-toluamide) and natural alternatives containing varying essential oils.  The study concluded that Bite Blocker, a commercial repellent (containing glycerin, lecithin, vanillin, oils of coconut, geranium, and 2% soybean oil)  could achieve similar repellency to DEET containing repellants.

In addition, some of the medicinal effects that stem (pun intended) from the geranium rose have been found to decrease anxiety.  A 2015 study evaluated the use of geranium essential oil as a non-invasive procedure that could decrease childbirth anxiety.  The study determined that the aroma geranium essential oils could effectively reduce anxiety during labor and could be recommended as a non-invasive anti-anxiety aid during childbirth.

Amazing!

Bottom line: Geranium rose oil provides antioxidant, anti-inflammatory, and anti-microbial capabilities.  It is also a plant-based insect repellent and has been shown to decrease anxiety levels.

Linalool is a monoterpene alcohol which can be found in many essential oils, such as that of spearmint, rose, cypress, lemon, and cinnamon.  It often evokes a fragrance to that of bergamot oil and lavender – and often functions as a flavoring and fragrance agent due to its pleasing scent – and therefore, often found in cleaning and laundry products.

One thing to note is that a 2017 study performed patch tests evaluations of 26 fragrance allergens on patients suffering from dermatitis. The study concluded that 940 out of 6004 patients were shown to be patch positive for linalool.

Bottom line:   Linalool is found in essential oils and provides antiseptic, antibacterial and anti-inflammatory properties.  It also functions as a flavoring and fragrance agent and found in cosmetics and perfumes.

We are no stranger to rosemary and its use in cosmetic products for its antioxidant, anti-inflammatory, and antibacterial capabilities.  We also are familiar with rosemary for its aromatic properties in foods.  But did you know – it has various analgesic and antibacterial properties? More specifically, rosemary oil has been effective against bacterium acne.  In 2007, a study found that there were significant changes in morphology and size of Propionibacterium acnes (P. acnes) in response to rosemary oil treatment.

This sounds promising, right?  

Acne sufferers from all over the world rejoice!  

Well before you start singing its praises – a study in 2005 reported a rare case of allergic contact dermatitis due to a cleansing gel containing rosemary extract (0.1% distilled water).  So if you suffer from sensitive skin outbreaks – be forewarned!

But in 2016, a study investigated the combination efficacy of rosemary and grapefruit in decreasing susceptibility to ultraviolet radiation, in addition to the improvement of skin wrinkledness and elasticity.  The study confirmed the photoprotective and anti-aging efficacy with combination use of rosemary and grapefruits.

Bottom line:  Used for its aroma and antibacterial properties for acne treatment.

Citronellol, a type of terpene, is often used as a fragrance compound in cosmetic products.  It has also been found to have potential antimicrobial properties.  High levels of citronellol are often found in geranium rose – roughly 28%.  

Both citronellol AND geraniol are listed as alleged fragrance allergens.  However, a 2010 study evaluated the penetration abilities of geraniol and citronellol when used in a vehicle in consumer products.  The study found (in vitro) that geraniol and citronellol have low potentials for skin penetration, which has implications for their ability to induce allergenicity and for more predictive toxicologic profiling of these materials.

Bottom line:   Citronellol is found in essential oils and provides antimicrobial capabilities.  It also functions as a fragrance agent and found in cosmetics. It may have the potential to be a fragrance allergen!

Geraniol is a monoterpenoid alcohol with antiseptic, antibacterial and anti-inflammatory properties.  It is often naturally occurring in rose oil and can also be found in other essential oils like lemon, geranium, vanilla, bergamot and lavender oil in lower concentrations.  

And guess what? Kiehl’s Midnight Recovery Concentrate just happens to have some of those essential oils!

Geraniol often functions as a flavoring and fragrance agent due to its pleasing scent – and therefore, often found in perfumes, cosmetics, and candles.  Something to note – as in most fragrance compounds (such as citronellol), geraniol may have the potential to elicit contact allergies.

Bottom line:   Geraniol is found in essential oils and provides antiseptic, antibacterial and anti-inflammatory properties.  It also functions as a flavoring and fragrance agent in cosmetics and perfumes. It may have the potential to be a fragrance allergen!

Lavandula Hybrida (also known as Lavandin or French lavender) oil is traditionally used as antiseptic and medicinal agents, and now predominantly used as a relaxant – providing as a form of sedative and neurological treatment through aromatherapy.

With the beauty and health industry morphing — more and more products are being formulated with essential oils.   You quite literally can’t walk by a beauty counter or drug store without seeing a product marketed with the promise of lavender oil’s therapeutic benefits – such as its antioxidant and anti-inflammatory properties and its use in fighting several skin diseases. Lavender oil is rich in antioxidants (e.g. terpenoids, lactones and phenolic compounds) and is composed of the following main molecules: linalool (34-47%), linalyl acetate (17-34%), camphor (4-9%) and eucalyptol (3-7%) as determined from a 2016 study.

For a while, most of the research surrounding the benefits of lavender oil applied topically wasn’t the most compelling. However, a 2016 study, recently evaluated lavender oil and its wound healing effect. The study concluded that topical application of lavender oil promoted collagen synthesis and up-regulation of TGF-β (needed for wound contraction).

This accelerated formation of tissue and collagen could be a game changer! The possibilities could be endless!

Bottom line: Lavender oil provides a natural aromatic fragrance that calms the mind and body. But the oil is composed of molecular components that prove quite beneficial as an antioxidant and anti-inflammatory agent; with new research unraveling possibilities for collagen synthesis!

Cucumis sativus (cucumber) fruit extract functions as a skin-conditioning agent in cosmetics.  But we all know what a cucumber is, right?!  We’ve had it in foods, our cocktails, and even our quintessential spa treatments – cucumber eyes!

The overall composition of the cucumber consists of ~96% moisture, ~0.4% proteins, ~0.1% fats, ~2.8%  carbohydrates, and trace minerals. Interestingly enough, cucumber contains a good amount of vitamins, phenolic acids, fatty acids, trace essential oils, and flavonoids – which happen to play a considerable amount of importance to its free-radical scavenging and antioxidant properties.

Its therapeutic potential seems to be unlimited – in its clarifying and detoxifying capabilities, and its soothing and emollient effect.

Bottom line:   Cucumbers function as a skin-conditioning agent in cosmetics with antioxidant and free-radical scavenging properties.

Curcuma longa (turmeric root) extract is another ingredient often associated with food seasoning.  It is also known for its anti-inflammatory, antimicrobial, and antioxidant properties?

The active phytochemical of turmeric is curcumin and has been used to treat a variety of skin conditions and diseases.  It’s even been used as an emollient! In fact, a 2007 study evaluated treatment of photo-aged skin based on increased pigmentation and fragility.  A herbal combination gel containing turmeric, rosemary, and gotu kola showed significant clinical skin improvements in 34-35 year olds after 4 weeks of topical treatment.

One thing to note is that curcumin has low bioavailability due to its rapid elimination from the body and poor absorption.  Some studies have observed that poor absorption issues may be thwarted by using black pepper in combination.

Bottom line: Turmeric root extract may be used as an emollient and is known for its anti-inflammatory, antimicrobial, and antioxidant properties.  

Limonene is a monoterpene with and a major component of essential oils from citrus fruits.  Limonene often functions as a flavoring and fragrance agent due to its lemon scent – and therefore, often found in perfumes, cosmetics, and candles.  It is often found in two forms, d-limonene (found in oranges) and l-limonene (found in lemons).

D-limonene and its metabolite were reported, in a 2014 study, to have tissue-repair properties.  The study noticed that topically applied d-limonene to patients with dermatitis and skin lesions demonstrated significant anti-inflammatory effects and contributed to healing effects on the epidermal barrier.

Although limonene has been designated as a chemical with low toxicity based upon lethal dose, skin irritation or sensitizing potential was reported following widespread use of this agent in various consumer products.

Bottom line:   Limonene is found in essential oils and provides anti-inflammatory and possible tissue-repair properties.  It functions as a flavoring and fragrance agent. And although there may be a potential for limonene to be a sensitizing allergen, some studies have pointed to its benefits in tissue-repair.

Citral is a well-known contact allergen and a contact irritant generally used as a flavor additive in food and fragrant component in cosmetic products. It is the major component of Cymbopogon citratus (lemongrass oil). In a 2003 study, evaluating citral sensitivities on patients exhibiting hand eczema found positive reactions to patch tests associated with citral.

Side note: A 2002 study in rats evaluated the sedative effects of specific essential components which included citral. The study showed that citral, limonene, and myrcene presented sedative as well as motor relaxant effects. Although only at the highest dose, they also produced potentiation of the pentobarbital-induced sleeping time in mice, which was more intense in the presence of citral.

A number of experimental and clinical studies have shown that citral has favorable anti-inflammatory and antibacterial properties.

Bottom line: Exhibits anti-inflammatory and anti-bacterial properties but may pose irritations with those who suffer from sensitive skin. Citral may provide a relaxing and calming response.

Sclareolide is a sesquiterpene lactone.  A natural product derived from various plant sources, including clary sage and cigar tobacco.  Sesquiterpene lactones are low molecular weight substances with antimicrobial, antioxidant, and growth-modifying properties.  There is also evidence to suggest that sesquiterpene lactones cause allergic dermatitis.  

Sclareolide is used for cosmetics and weight-reduction products, with some studies using sclareolide in combination cancer therapy.  

This seems rather strange, right?  

Why would the folks at Kiehl’s add this to the formulation?

But aside from that, not much was really found on this specific compound as far as published studies or data.

Based on trademarked vendor compounds, sclareolide may be the following:

• A fragrant component in cosmetics and tobacco products.  Found to have excellent thermogenic properties and could be used to aid in weight loss and sports nutrition., Bolise (Sclareolide).
• Food additive that is derived from the clay sage plant. It is in the form of a white crystal powder, and is used as an additive in certain diet foods and sport nutrition applications., Penta Manufacturing Company (Sclareolide).

Bottom line: Sclareolide is a sesquiterpene lactone with limited data and research with respect to cosmetics application.  

We’ve reviewed varying forms of rose flower oil but this doesn’t seem to be very specific to which type of rose oil used in the formulations.

Regardless, where would aromatherapy be without the smell of the rose?

For centuries, humans have studied every aspect of this plentiful flower. The rose and its petals are often a symbol of love. In a 2007 study, 95 macro and micro components in the essential oil of Rosa Damascena (R. damascena) from central Iran. The identified components were β-citronellol (14.5-47.5%), nonadecane (10.5-40.5%), geraniol (5.5-18%), and nerol and kaempferol were the major components of the oil.

In addition, some of the medicinal effects that stem (pun intended) from the R. damascena are partly attributed to their abundance of phenolics compounds – resulting as strong antioxidants, free-radical scavengers, and exhibiting anti-inflammatory/anti-mutagenic/anti-depressant capabilities.

Kiehl’s Midnight Recovery Concentrate also includes rosa canina fruit oil which contains an abundance of fatty acids!

Bottom line:   Rosa flower oil functions as a skin conditioning agent, fragrance ingredient, astringent, anti-acne agent, humectant, and exfoliant in cosmetic products.  Due to its high fatty acid content – it often provides anti-inflammatory and antioxidant capabilities. It has also been shown to improve skin hydration and elasticity.  In the end, the essential oil is packed with phenolic compounds and has a strong antioxidant capacity.

Jasmine is often used in aromatherapy and is often seen to provide a level of relaxation, calmness, and relief from depression.  Applied topically, it would seem, the smell would provide a “spa-like” experience to the skincare mask treatment. And there have been studies that point to its antibacterial properties.  

Therefore, for all intents and purposes, the use of jasmine seems to have no definitive skincare benefits and is simply used for its aromatic effect.

Bottom line: Jasmine is a natural aromatic fragrance used to preemptively calm the mind during a spa-like treatment.

According to a comprehensive analysis of seed oils performed in 1992, sunflower oil contains high levels of vitamins A, D, and K – with crude sunflower oil having the highest content of vitamin E in the form of α-tocopherol amongst oils.

In a randomized study in 2013, sunflower seed oil preserved stratum corneum integrity (that’s skin talk) – and improved hydration in volunteers who applied it topically after 4 weeks. Oddly enough, the study also found that in contrast; topical treatment of sunflower oil WITH olive oil significantly damaged the skin barrier, and therefore had the potential to promote the development of and exacerbate existing atopic dermatitis.  Thankfully, the Kiehl’s Midnight Recovery Concentrate does not include olive oil.

And finally, helianthus annuus sunflower seed oil has a fatty acid composition of the following according to the CIR panel:

• Oleic acid (14.7-37.2%), an omega-9 fatty acid
• Linoleic acid (51.5-73.5%), an omega-6 fatty acid
• Linolenic acid (0.3%), an omega-3 fatty acid
• Palmitic acid (5-7.2%)
• Stearic acid (2-6.5%)

Bottom line: High vitamin E content for improved hydration.