Eructos

Acemannan is the primary bioactive polysaccharide from Aloe vera gel, acting as a humectant and water-retaining agent in the stratum corneum. It is responsible for the moisture-binding activity of aloe gel and supports skin barrier function. Evidence from aquaporin-3 upregulation studies and clinical aloe research directly implicates acemannan in dry skin improvement.

Alpha-linolenic acid (ALA) is a plant-based essential omega-3 fatty acid that supports skin barrier function and hydration. Essential fatty acid deficiency (including ALA) causes dry, scaly skin, and supplementation reverses this. Evidence from cellular, animal, and human studies confirms topical ALA can improve skin barrier integrity and reduce dry skin.

Allantoin acts as a humectant and keratolytic agent, increasing water content in the stratum corneum and reducing transepidermal water loss (TEWL). The FDA recognizes allantoin as an OTC skin protectant at 0.5–2%, and clinical formulations containing allantoin have demonstrated measurable improvements in skin hydration. It is widely incorporated into moisturizer products for dry skin conditions.

Clinical evidence from RCTs in postmenopausal women shows that almond consumption improves skin hydration measures and reduces transepidermal water loss (TEWL). Almonds' high content of essential fatty acids and vitamin E are proposed to support the skin lipid barrier and reduce moisture loss.

Aloe vera gel is traditionally used across multiple cultures for dry, irritated skin and scientifically confirmed to improve skin hydration. In vivo studies show topical aloe increases skin moisture and reduces TEWL via its mucilaginous polysaccharide acemannan. Clinical research also demonstrates aloe extract upregulates aquaporin-3, the water channel responsible for stratum corneum hydration.

Alpha hydroxy acids (AHAs) such as lactic acid and glycolic acid treat dry skin by promoting desquamation of thickened, accumulated dead corneocytes and improving stratum corneum hydration via humectant properties. Lactic acid is a natural moisturizing factor component that directly increases skin water content. Multiple clinical dermatology studies confirm AHAs improve xerosis and skin smoothness.

Human clinical data in postmenopausal women show that both topical and oral argan oil significantly reduce transepidermal water loss (TEWL) and improve skin hydration. It is a well-supported moisturising agent for dry skin.

Multiple studies confirm that topical ascorbyl palmitate has significant moisturizing activity. A PubMed-indexed study found that AP in solid lipid nanoparticle (SLN) and nanostructured lipid carrier (NLC) hydrogels moisturized skin significantly better than placebo in both short-term (p<0.001) and long-term trials (p<0.01). AP's hydrophilic palmitate moiety is believed to contribute to its skin-conditioning properties.

Oral borage seed oil supplementation has been shown in a controlled human study to significantly improve skin barrier function in elderly subjects, as measured by reduced transepidermal water loss (TEWL). GLA is required for normal epidermal barrier lipid synthesis, and supplementation compensates for age-related decline in delta-6-desaturase activity.

Borage oil contains at least 23% gamma-linolenic acid (GLA)—approximately 2–3x more than evening primrose oil—and is used to address dry and atopic skin by restoring skin barrier lipids. Placebo-controlled double-blind studies show modest improvements in skin hydration and dry skin symptoms. Its GLA content bypasses the impaired delta-6-desaturase step associated with dry/atopic skin.

Calendula is incorporated into a large number of cosmetic emollient formulations for dry and sensitive skin. The EMA recognises it for minor skin inflammation and wound healing, which includes compromised barrier function seen in dry skin. Clinical use is well-established, with hydrating and soothing properties attributed to mucilaginous polysaccharides and carotenoids.

Beta-carotene from carrots is converted to vitamin A (retinol), which is essential for skin cell turnover, epithelial maintenance, and sebaceous gland function. Vitamin A deficiency causes xerosis (dry, scaly skin), and adequate beta-carotene intake supports skin hydration and barrier integrity.

Ceramides are lipids naturally comprising ~50% of stratum corneum lipids; their depletion causes dry, barrier-disrupted skin. Multiple RCTs and a 2021 systematic review (12 comparative studies) confirm topical ceramide formulations improve skin hydration and repair barrier function in dry skin and xerosis. Oral ceramide supplementation has also shown hydration benefits in clinical trials.

Clinical trials and in vitro studies show cacao powder significantly improves skin hydration and moisture retention. A 12-week RCT demonstrated significant improvement in skin hydration after cacao powder consumption. In vitro, cacao powder promotes hyaluronic acid production in keratinocytes and reduces transepidermal water loss.

Level 1 RCT evidence demonstrates topical VCO is effective for xerosis (clinically dry skin), performing comparably to or better than mineral oil. A WHAM evidence summary assigned Grade B recommendation for VCO in mild-to-moderate xerosis. Application twice daily to affected areas is the established dosing protocol.

Topical application of virgin coconut oil—pressed from coconut milk—has demonstrated efficacy comparable to mineral oil for treating dry skin in clinical studies. It reduces transepidermal water loss (TEWL) and provides barrier protection for the stratum corneum. Clinical studies have shown VCO improves skin hydration and moisture markers.

Multiple RCTs have confirmed that topical virgin coconut oil effectively moisturizes dry skin, reduces transepidermal water loss (TEWL), and improves skin barrier function. A double-blind RCT in 117 pediatric atopic dermatitis patients found VCO superior to mineral oil on SCORAD scores, TEWL, and skin capacitance over 8 weeks. Coconut oil is widely used in tropical-region traditional medicine as a moisturizer.

Omega-3 fatty acids from cod liver oil maintain skin barrier function and hydration by being incorporated into epidermal phospholipids. Vitamin A supports skin cell turnover and barrier integrity. Both nutrients are associated with improved skin moisture and reduced transepidermal water loss.

Oral hydrolyzed collagen peptides improve skin hydration in multiple randomized double-blind placebo-controlled trials and meta-analyses. Collagen peptides stimulate dermal fibroblast synthesis of new collagen, elastin, and hyaluronic acid, reducing TEWL and improving dry skin. A 12-week RCT (n=64, 1000 mg/day) showed significantly higher skin hydration values versus placebo at 6 and 12 weeks.

Alpha-tocopherol is the predominant antioxidant in the stratum corneum and has well-established moisturizing and barrier-supporting properties in skin. Its sebaceous delivery system maintains epidermal lipid integrity, and topical application is broadly documented to reduce transepidermal water loss and support barrier function in dry and compromised skin.

DHA is a long-chain omega-3 PUFA from fish and microalgae that integrates into skin cell membranes, improving membrane fluidity and barrier function and reducing TEWL. Systematic reviews and clinical studies confirm DHA-containing preparations improve dry skin and enhance barrier integrity. Together with EPA, DHA reduces pro-inflammatory mediators that compromise skin barrier hydration.

EPA contributes to skin barrier integrity by modulating epidermal lipid composition and suppressing inflammatory eicosanoids that degrade the stratum corneum. Clinical and mechanistic studies link adequate omega-3 status, particularly EPA, to improved skin hydration and reduced transepidermal water loss.

EPA is a long-chain omega-3 PUFA from fish and algae with well-documented anti-inflammatory effects directly relevant to skin barrier dysfunction and dry skin. EPA-derived mediators inhibit pro-inflammatory neutrophil and keratinocyte signaling that drives barrier compromise and dryness. Clinical studies and systematic reviews confirm EPA supplementation improves skin moisture and barrier function.

Evening primrose oil (EPO) contains 8–10% gamma-linolenic acid (GLA) and has been widely studied for dry skin and atopic eczema. RCTs show EPO reduces TEWL, improves skin hydration, and decreases objective eczema scores; GLA plasma levels correlate with clinical improvement. It has been used as both a prescription and OTC remedy for dry, scaly skin.

Omega-3 PUFAs from fish oil are structural components of the skin's lipid barrier and modulate cutaneous inflammation. Clinical evidence shows fish oil supplementation improves skin moisturization and reduces pruritus in conditions associated with dry skin. A prospective cohort study in hemodialysis patients (n=31) found 1,000 mg/day fish oil for 3 months significantly improved skin moisture and reduced inflammatory pruritus.

A clinical trial found that 12 weeks of flaxseed oil supplementation significantly improved skin hydration, sensitivity, roughness, and smoothness. Clinical results of PUFA supplementation on skin barrier parameters (hydration, transepidermal water loss, roughness) are documented in peer-reviewed dermatology literature.

GLA is an omega-6 fatty acid from evening primrose, borage, and blackcurrant oils that restores skin barrier lipids impaired by delta-6-desaturase deficiency in dry/atopic skin. Clinical studies confirm GLA plasma levels correlate with dry skin improvement, and supplementation reduces TEWL and inflammatory barrier dysfunction. GLA converts to DGLA, producing anti-inflammatory prostaglandins that support skin hydration.

Glycerin (glycerol) is one of the most well-established humectants for dry skin, attracting and retaining water in the stratum corneum. Scientific studies confirm it improves skin moisture content, elasticity, and barrier properties. Research has elucidated its mechanism via aquaporin-3 channels and demonstrated its concentration-dependent moisture-retention capacity.

Glycosylceramides are plant-derived ceramide precursors that improve skin hydration when taken orally. A randomized clinical study of Konjac-derived glucosylceramides demonstrated improved skin moisture and reduced dry skin discomfort. Orally administered glycosylceramides are hydrolyzed to ceramides in the intestine, absorbed, and distributed to the skin.

Honey's humectant, emollient, and antimicrobial properties support skin hydration and barrier function. Reviews of honey phytochemicals (2024, Phytotherapy Research) document its skin barrier-enhancing, anti-inflammatory, and wound-healing properties. Clinical studies of honey in atopic dermatitis (a condition marked by dry, inflamed skin) have shown benefit.

Hyaluronic acid (HA) is a key endogenous skin humectant capable of binding up to 1000x its weight in water. Multiple randomized double-blind placebo-controlled trials confirm that both topical and oral HA significantly improve skin hydration and reduce dry skin symptoms. A 12-week RCT (n=40) found significantly higher stratum corneum water content in the HA group vs. placebo.

In vivo human volunteer studies using H. italicum extract-impregnated textiles confirmed improvements in skin electrical capacitance (hydration) and reductions in transepidermal water loss, supporting its skin-moisturising and barrier-protective effects.

Two 2024 randomized, double-blind, placebo-controlled pilot studies (Handeland et al., PMID 39169540; n=51 and n=50 healthy adults) found that 1 g and 2 g of krill oil/day for 12 weeks produced significant, dose-dependent reductions in transepidermal water loss (TEWL) and improvements in skin hydration compared to placebo. Effects correlated linearly with increases in the omega-3 index.

Linoleic acid (LA) is an essential omega-6 fatty acid that is the obligatory component of skin acylceramides; LA deficiency causes dry, scaly skin with elevated TEWL. Topical LA replenishes stratum corneum ceramide fractions and restores barrier function. Systematic review evidence confirms topical LA-rich preparations enhance skin barrier integrity and improve dry skin.

Marshmallow root mucilage forms a moisture-retaining film on skin, documented in clinical and in vitro research. A human study found a 20% marshmallow root extract ointment significantly reduced skin irritation and improved hydration. Its polysaccharides support skin barrier function and moisture retention.

Oral and topical NAG has demonstrated improvements in skin moisture content in placebo-controlled clinical studies. NAG serves as a direct precursor to hyaluronic acid (HA) biosynthesis, driving skin hydration. An 8-week double-blind placebo-controlled trial in women with habitually dry skin found significant improvement in stratum corneum moisture content at 500 mg/day oral NAG.

Colloidal oatmeal is an FDA-approved OTC skin protectant with well-documented clinical efficacy for dry skin. Multiple clinical studies and a large retrospective analysis confirm improvements in dryness, roughness, desquamation, and transepidermal water loss with colloidal oatmeal-containing products.

Oleic acid is a major constituent of the skin's natural lipid barrier and is used topically to replenish lost lipids and improve skin hydration. It penetrates deeply into skin layers and helps restore barrier function. Clinical and ex-vivo studies confirm that unsaturated fatty acids including oleic acid contribute to maintaining and restoring the skin's lipid barrier.

Topical olive oil has been traditionally and clinically used to moisturize dry skin, with its fatty acid composition providing occlusive and emollient properties. However, RCT evidence shows that while olive oil can temporarily improve hydration, its high oleic acid content may increase transepidermal water loss with prolonged use on some skin types.

Omega-3 fatty acids (primarily EPA and DHA) integrate into skin cell membrane phospholipids, improving barrier function and reducing TEWL. Clinical supplementation studies demonstrate increased skin hydration within 8–12 weeks and reduced inflammatory barrier dysfunction. Systematic reviews confirm topical and oral omega-3 PUFAs improve dry skin.

Linoleic acid (LA) is an essential structural component of skin ceramides and is required for formation of the epidermal water-permeability barrier. Deficiency of dietary omega-6/LA leads to transepidermal water loss, scaly dermatoses, and dry, disrupted skin. Both oral supplementation and topical application of omega-6-rich oils have documented effects on skin hydration and barrier function.

Oral and topical sea buckthorn oil, containing omega-7 palmitoleic acid, has demonstrated skin hydration improvements in controlled trials. A 12-week randomized, double-blind, placebo-controlled study (n=90) using 500 mg/day oral palmitoleic acid significantly improved skin hydration and reduced transepidermal water loss (TEWL) versus placebo. A topical sea buckthorn lotion RCT in healthy males also showed significant skin hydration improvements over 8 weeks.

Ophiopogon root polysaccharides physically retain moisture and repair skin barrier function, and this is supported by in vitro and cosmetic science evidence. The β-fructan polysaccharides reduce nitric oxide and inflammatory pathways while hydrating the skin. A clinical study with oligofructosane fractions from O. japonicus demonstrated benefit in atopic dermatitis — a condition defined by pathological skin dryness.

Palmitic acid is a natural component of the skin's lipid barrier, alongside ceramides and cholesterol. Applied topically, it functions as an emollient that forms a protective film, prevents transepidermal water loss, and supports the stratum corneum barrier against dryness, irritants, and allergens. It is widely used in dermatological formulations for dry skin at concentrations of 5–15%.

POA is a native component of the viable epidermis that supports the skin lipid barrier. A 12-week RCT in 90 women showed oral POA supplementation (500 mg/day) significantly improved skin hydration and reduced transepidermal water loss compared with placebo.

Panthenol (provitamin B5) is a clinically validated skin humectant and conditioning agent converted to pantothenic acid in the skin, where it supports ceramide synthesis and barrier function. Clinical studies confirm panthenol-containing formulations (1–5%) significantly increase skin moisture content and reduce TEWL. It is recognized as a skin-conditioning humectant by cosmetic safety regulatory authorities.

RCT evidence shows Pycnogenol supplementation improves skin hydration and elasticity, particularly in women with dry skin. Six weeks of supplementation increased hydration by 21% in dry-skin subjects vs. 8% in normal-skin subjects. Mechanisms include upregulation of hyaluronic acid synthase and collagen type I synthesis.

Rosehip preparations—both topical and oral—have demonstrated improvements in skin moisture in clinical trials. An 8-week double-blind RCT in 34 subjects showed standardized rosa canina powder increased forehead moisture content. Rosehip oil, rich in essential fatty acids, supports the skin barrier and reduces transepidermal water loss.

Topical sesame oil has been shown in a human study (35 volunteers, average age 20) to increase skin hydration by nearly 30% after a single application. Sesame oil's fatty acid composition (particularly oleic acid) forms a barrier film on the epidermis that reduces transepidermal water loss. It is widely used as an emollient in dermatology and traditional medicine.

Shea butter is one of the most clinically supported natural emollients for dry skin. It reduces transepidermal water loss (TEWL) significantly within hours of application and increases skin hydration measurably over weeks. Its fatty acid profile closely mirrors the skin's natural lipid composition, reinforcing the stratum corneum barrier.

Squalene is a major natural component of human sebum (~12–13%), where it contributes to skin hydration and barrier integrity. Its hydrogenated form (squalane) has been studied in clinical and ex-vivo contexts, demonstrating reduced transepidermal water loss (TEWL) and restored skin barrier function. Squalene production declines from the mid-twenties onward, contributing to age-related dryness. Topical formulations containing squalane are used to replenish this deficit.

Sunflower seed oil is a well-documented skin emollient that significantly reduces transepidermal water loss (TEWL) and improves hydration. A 2018 clinical study demonstrated sunflower oil improved skin hydration in adults without irritation. Its high linoleic acid content helps maintain the stratum corneum lipid barrier and locks in moisture.

Clinical studies demonstrate that topical sunflower oil reduces transepidermal water loss (TEWL), improves skin hydration, and maintains the skin barrier, making it effective for dry skin. A human study of 19 volunteers found sunflower oil superior to olive oil in improving skin hydration and maintaining the skin's outer layer integrity. It is evidenced for xerosis and dry skin in adults.

Vitamin A and its retinoid derivatives are established regulators of keratinocyte differentiation and epidermal barrier function. Deficiency causes xerosis (dry, scaly skin) and follicular hyperkeratosis. Topical retinoids improve skin hydration, texture, and barrier integrity, supported by multiple clinical studies.

Niacinamide (vitamin B3 amide) strengthens the skin barrier by stimulating ceramide, fatty acid, and natural moisturizing factor synthesis in keratinocytes, thereby reducing TEWL and improving skin hydration. Clinical RCTs and JAAD studies confirm niacinamide-containing formulations improve barrier recovery in dry skin. It is a standard ingredient in dermatologist-recommended dry skin moisturizers.

Topical dexpanthenol (provitamin B5) has been shown in clinical studies to reduce transepidermal water loss (TEWL) and improve skin hydration. Its activity is linked to its role as a CoA precursor driving ceramide and fatty acid synthesis in the epidermis. Dexpanthenol cream has also been studied to manage xerosis during isotretinoin therapy.

Vitamin E (tocopherol) is a lipid-soluble antioxidant that protects skin cell membranes from oxidative damage contributing to dryness. Clinical and in vitro studies confirm topical vitamin E improves skin moisture content, reduces roughness, and supports barrier function in dry skin. It has a long established use in dermatology as a moisturizing and barrier-supportive ingredient.

Wheat germ oil is readily absorbed by human skin and is rich in vitamin E, linoleic acid, and other unsaturated fatty acids that restore the skin barrier and seal moisture. It has been used topically as a moisturizer with a scientifically grounded mechanism. Clinical dermatology supports its use for dry and cracked skin.

Apricot kernel oil is a traditional topical emollient used for centuries in Central and South Asian cosmetic traditions to soften and moisturize dry skin. The oil is rich in oleic and linoleic acids, which support skin barrier function. Vitamin A precursors in the fruit support epithelial cell turnover. Commercial apricot kernel oil remains widely used in cosmetic formulations for dry skin.

Chickweed is a well-established traditional topical remedy for dry, irritated skin due to its demulcent mucilage content. Applied as creams, salves, or infused oils, it is considered to moisturize and soothe dryness. No clinical trials exist specifically for dry skin.

Cottonseed oil has documented traditional use as a topical skin moisturizer and emollient, particularly in Ayurvedic traditions and in Tamil Nadu where cottonseed milk (paruthi paal) is a skincare staple. Its linoleic acid content is mechanistically relevant to skin barrier maintenance. A 2025 review in Frontiers in Pharmacology noted CSO's linoleic-to-oleic acid ratio supports skin barrier function, though direct clinical trials on dry skin are lacking.

Cucumber has a long history of topical use for dry, irritated skin across Ayurvedic and European folk traditions. Its high water content and the presence of silica are proposed to support skin hydration. Cucumber extract is a recognised cosmetic ingredient used in moisturising formulations.

Eicosenoic acid (C20:1) is the dominant fatty acid in meadowfoam seed oil (comprising approximately 61% of its fatty acid content) and is also found in jojoba oil. These oils are widely used as emollients in cosmetic and topical skin-care formulations for moisturization and skin conditioning. The emollient, permeation-enhancing, and soothing properties attributed to eicosenoic acid in this context are based on traditional and cosmetic use rather than controlled clinical trials specifically on the isolated fatty acid.

Geranium EO is traditionally used in skin-care preparations for its moisturizing and sebum-balancing properties. It is recognized in herbal medicine for improving dry and mature skin conditions. No clinical trial evidence is available for this specific indication.

In TCM, glehnia root is considered a yin-nourishing herb that addresses dryness-related conditions including dry skin, attributed to 'lung yin deficiency.' Tibetan medicine also records its use for skin diseases. No clinical trials have examined topical or systemic effects on skin.

In TCM, lily bulb is traditionally described as promoting vital fluids and improving skin complexion, attributed to its high mucilage and vitamin content. It is documented as a skin-beautifying herb in classical texts. Modern research confirms lily extracts possess antioxidant and antimicrobial activities relevant to skin health and are increasingly incorporated into dermatocosmetic formulations.

Macadamia nut oil has a longstanding traditional use as a topical moisturizer for dry skin, attributed to its high palmitoleic acid and squalene content that mimic skin sebum. It helps repair the skin barrier and reduce trans-epidermal water loss. While mechanistically plausible, large controlled clinical trials specifically demonstrating efficacy for dry skin are limited.

Safflower oil is rich in linoleic acid (~75%), a key fatty acid for skin barrier function and moisture retention. Traditional and cosmetic use of safflower oil for dry skin is well-established; its lightweight texture facilitates skin absorption. Safflower seed extracts also contain skin-whitening and antioxidant compounds relevant to skin health.