Ceramide 3; Ceramides(in 12,171 products)
1. Anti-aging - Prevents or slows aging, and causes the skin to appear more youthful
2. Emollient - Softens and soothes the skin. Helps with skin conditioning.
Ceramide NP is a lipid molecule included in a group of lipid molecules called ceramides. Ceramides are major lipid components in the stratum corneum of the human skin. Ceramide 3 consists of a phytosphingosine backbone N-acylated with a saturated fatty acid (stearic acid). It is widely used as a moisturizer in various cosmetic and personal products. Together with ceramide 1, they synergistically improve the skin barrier function in humans. 
Ceramides are a family of waxy lipid molecules that make up the epidermis (top layer) of the skin. Those ceramides prevent the skin from losing moisture and loss of ceramides can cause itching, peeling, and flaking.
Ceramide 3 or Ceramide NP accounts for approximately 22.1% of the total ceramide pool in the stratum corneum (the uppermost layer of skin).  It is also sometimes called Ceramide NP where the N stands for the amide-linked fatty acid and P stands for the phytosphingosine base, giving Ceramide N-stearoyl phytosphingosine (Ceramide NP).
Ceramides in the Stratum Corneum (SC)
“In patients with atopic dermatitis, the levels of ceramide 1 and 3 were significantly lower and values of cholesterol significantly higher with respect to healthy subjects” , which could also result in “the decrease in ceramides 1 and 3 [which] may account for skin susceptibility to irritants and increased TEWL [transepidermal water loss, which is water loss from the skin]”. 
In a similar study related to atopic dermatitis, “there was a marked reduction in the amount of ceramides in the lesional forearm skin compared with those of healthy individuals of the same age.” . With up to a 30% reduction in ceramides and a 50% reduction in lipids in those with atopic dermatitis compared to healthy individuals. The study concluded that “findings suggest that an insufficiency of ceramides in the stratum corneum is an etiologic factor in atopic dry skin.” where “total stratum corneum lipids/mg stratum corneum declines with age, suggesting the total reduction of lipid synthesis in aged skin.”  It noted that “Among six ceramide fractions, ceramide 1 was most significantly reduced in both lesional and non-lesional skin.” with ceramide 3 having the next highest reduction. 
Ceramide 1 & 3
“It has been reported that ceramide 1 is very important for appropriate barrier function of the stratum corneum and for the molecular organization of stratum corneum lipids.” while "lipid-rich emollients containing ceramide 3 may be of benefit in skin barrier disruption following tape stripping.”  Although ceramides amphipathic lipids which are key in the formation of lipid bilayers with water-holding properties , “ceramides are extremely water-insoluble compounds, which can form a water-impermeable barrier in the skin”.  Hence, an effective emulsifier is required for ceramides to reach its maximum efficacy.
In an experiment conducted on volunteers via experimentally induced skin dysfunction in a physical manner (tape-stripping) and in a chemical manner (use of sodium dodecyl sulphate, SDS), “studies of lipid composition of atopic skin showed a lowered level of ceramides, especially ceramide 1, suggesting its important role in barrier function”.  “At day 4, ceramide 3-containing emollient significantly decreased (p<0.03) the erythema score, TEWL and cycling cells in comparison with the untreated site” demonstrates the effectiveness of ceramide 3, "it is unknown whether emollients with ceramide 3 could sufficiently replace the role of ceramide 1 and other natural occurring ceramides”.  Since "it is assumed that especially ceramide 1 is of major importance for proper stratum corneum barrier function”, and not ceramide 3.  Overall, ceramide-containing emollients are more effective on chemically induced skin dysfunction rather than on physically induced skin dysfunction, the authors concluded that "these results support the hypothesis that the optimal barrier repair therapy should be based on the specific damage and recovery" and "that an ideal emollient does not exist and that a specific emollient will not be appropriate for all clinical purposes". 
In a study conducted on 20 female volunteers, “no additional positive effect on the TEWL values of SLS-damaged skin could be observed when the efficacy of the ceramide-containing emulsions was compared with that of proper controls.” while concluding that their "experience shows no real proof that ceramide 3B in a final concentration of 0.2% (w/v) exerts a more beneficial effect on SLS-damaged skin than that of commonly used lipid ingredients”.  However, this can mainly be attributed to the lack of a proper emulsifier as “when topically applied, the oleosomes (ceramide oil droplets) are mainly confined to the horny layer (SC) and do not penetrate deeper into the epidermis”. 
3. Ceramide and cholesterol composition of the skin of patients with atopic dermatitis. (Acta Derm. Venereol., 78(1), 27–30. doi:10.1080/00015559850135788)
4. Decreased Level of Ceramides in Stratum Corneum of Atopic Dermatitis: An Etiologic Factor in Atopic Dry Skin? (J. Invest. Dermatol., 96(4), 523–526. doi:10.1111/1523-1747.ep12470233)
5. Ceramide 1 and ceramide 3 act synergistically on skin hydration and the transepidermal water loss of sodium lauryl sulfate-irritated skin. (Int. J. Dermatol., 47(8), 812–819. doi:10.1111/j.1365-4632.2008.03687.x)
6. Effect of a lipid-rich emollient containing ceramide 3 in experimentally induced skin barrier dysfunction. (Contact Derm., 46(6), 331–338. doi:10.1034/j.1600-0536.2002.460603.x)
7. Incorporation of ceramide 3B in dermatocosmetic emulsions: effect on the transepidermal water loss of sodium lauryl sulphate-damaged skin. (J. Eur. Acad. Dermatol. Venereol., 14(4), 272–279. doi:10.1046/j.1468-3083.2000.00103.x)
Safety and Hazards (UN GHS):
1. Causes serious eye irritation (H319)
Potential Health Concerns For:
1. Alzheimer Disease (PubMed ID:15223066)