A gentle, effective humectant that hydrates without the stickiness of glycerin or the potential irritation of regular urea.
Irritation
low
Source
synthetic
Beauty ingredient research
Browse the review database to understand what an ingredient is, what it does in a beauty formula, when it is useful, and when it deserves caution across skincare, haircare, bodycare, makeup, and more.
20769
Reviewed ingredients
524
Low-concern standouts
2884
Need usage caution
A gentle, effective humectant that hydrates without the stickiness of glycerin or the potential irritation of regular urea.
Irritation
low
Source
synthetic
A gentle amino acid that helps hydrate and calm the skin, making it a good choice for sensitive or dry skin types.
Irritation
low
Source
natural
Hydroxyproline is a collagen-building amino acid that may help firm and hydrate skin with minimal irritation risk.
Irritation
low
Source
natural
Humectant
HYDROXYPROPYL STREPTOCOCCUS ZOOEPIDEMICUS FERMENT FILTRATE
A gentle, biotech-derived humectant that boosts skin hydration and supports a healthy moisture barrier without irritation.
Irritation
low
Source
biotech
A gentle, synthetic humectant that draws moisture into the skin without the stickiness of glycerin, making it a good option for lightweight hydration.
Irritation
low
Source
synthetic
A gentle, amino-acid-based humectant that helps hydrate and soothe skin without irritation.
Irritation
low
Source
semi-synthetic
A gentle, sugar-derived humectant that helps hydrate skin without stickiness, suitable for sensitive and dry skin types.
Irritation
low
Source
semi-synthetic
A gentle, high-performance hyaluronic acid derivative that sticks to skin better than standard HA for deeper, longer-lasting hydration.
Irritation
low
Source
semi-synthetic
A gentle, mineral-rich plant juice that helps hydrate and calm the skin, but scientific evidence is still emerging.
Irritation
low
Source
natural
A gentle, hydrating plant water that may help soothe and protect the skin, but research is limited.
Irritation
low
Source
natural
A gentle, plant-based humectant that helps skin hold onto moisture without feeling heavy or greasy.
Irritation
low
Source
natural
Inositol is a gentle humectant that helps hydrate and soothe the skin, making it a good option for sensitive or dry skin types.
Irritation
low
Source
natural
A gentle, multi-tasking humectant that helps hydrate and soothe the skin, making it a good choice for sensitive or dry skin types.
Irritation
low
Source
semi-synthetic
Inulin is a gentle, plant-derived prebiotic that hydrates and supports a balanced skin microbiome, making it a smart choice for sensitive or microbiome-conscious routines.
Irritation
low
Source
natural
A gentle, hydrating seaweed extract that helps skin retain moisture and feel soothed, ideal for dry or sensitive skin types.
Irritation
low
Source
natural
A gentle brown algae extract that helps hydrate and protect skin with antioxidant benefits, though research is still emerging.
Irritation
low
Source
natural
Isoleucine is a gentle amino acid that helps maintain skin hydration and supports the skin's natural repair processes.
Irritation
low
Source
natural
Isomalt is a gentle, sugar-derived humectant that helps skin retain moisture without stickiness.
Irritation
low
Source
semi-synthetic
A gentle, multi-tasking humectant that hydrates skin and helps other ingredients work better without causing irritation.
Irritation
low
Source
synthetic
Isopropyl PCA is a gentle, synthetic humectant that helps hydrate skin without feeling heavy, making it a good option for normal to dry skin types.
Irritation
low
Source
synthetic
Isosorbide is a gentle, plant-based humectant that hydrates skin without stickiness, making it a good alternative to glycerin or hyaluronic acid.
Irritation
low
Source
natural
A mild, amino-acid-based moisturizer that supports the skin’s natural hydration without clogging pores.
Irritation
low
Source
semi-synthetic
A gentle, hydrating base ingredient from Japanese apricot fruit that may offer antioxidant and soothing benefits, but research is limited compared to more studied fruit waters.
Irritation
low
Source
natural
A gentle, hydrating sap that soothes skin and provides antioxidant benefits, ideal for sensitive or dry skin types.
Irritation
low
Source
natural
Humectant
Tenacibaculum Jejuense/Oat Bran Extract/Volcanic Ash Extract Ferment Filtrate
A fermented ingredient that may help hydrate and soothe skin, but research is still early.
Irritation
low
Source
biotech
Jojoba Amino Acids are a gentle, plant-based humectant that helps hydrate and support the skin barrier without clogging pores.
Irritation
low
Source
natural
Kefiran is a gentle, hydrating polysaccharide from kefir that helps skin retain moisture and may support a healthy-looking barrier.
Irritation
low
Source
natural
A mineral-rich seaweed extract that hydrates and soothes skin, but its benefits come mostly from its nutrient profile rather than unique active compounds.
Irritation
low
Source
natural
A mineral-rich seaweed juice that hydrates and soothes skin without clogging pores.
Irritation
low
Source
natural
A gentle, hydrating seaweed extract that helps soothe and moisturize skin without clogging pores.
Irritation
low
Source
natural
A gentle, seaweed-derived ingredient that may help hydrate and calm the skin, though research is still emerging.
Irritation
low
Source
natural
A gentle, hydrating ingredient that combines fruit extract with beta-glucan to help soothe and moisturize the skin.
Irritation
low
Source
natural
A gentle brown seaweed powder that helps hydrate and soothe the skin, ideal for sensitive or dry skin types.
Irritation
low
Source
natural
A gentle, hydrating seaweed extract that may support skin barrier function and calm irritation.
Irritation
low
Source
natural
A nutrient-rich seaweed extract that helps hydrate and calm the skin, with antioxidant benefits from coastal minerals.
Irritation
low
Source
natural
A gentle, fermented ingredient that hydrates and soothes skin, but its benefits are mostly anecdotal and backed by limited clinical research.
Irritation
low
Source
natural
Konjac root extract is a gentle, plant-based humectant that helps hydrate and soothe the skin without clogging pores.
Irritation
low
Source
natural
A gentle, fat-free milk ingredient that hydrates and soothes skin, but its benefits are mild compared to more concentrated actives.
Irritation
low
Source
natural
A gentle humectant that helps attract moisture to the skin, similar to lactic acid but without the exfoliating effect.
Irritation
low
Source
semi-synthetic
A gentle humectant that helps skin retain moisture and may improve texture, suitable for most skin types.
Irritation
low
Source
semi-synthetic
Lactic acid is a gentle AHA that exfoliates dead skin cells while also attracting moisture, making it a great choice for dry or sensitive skin types looking for smoother texture.
Irritation
moderate
Source
natural
Lactide is a gentle, biodegradable exfoliant that helps smooth skin texture and boost hydration without harsh irritation.
Irritation
low
Source
semi-synthetic
A gentle milk protein that helps hydrate and soften skin, but may not suit those with dairy allergies.
Irritation
low
Source
natural
A gentle milk protein extract that helps hydrate and temporarily smooth the skin, but may not suit those with dairy allergies.
Irritation
low
Source
natural
Lactitol is a gentle, non-irritating humectant and mild exfoliant that helps hydrate and smooth skin without causing breakouts.
Irritation
low
Source
semi-synthetic
Soothing agent
LACTOBACILLUS/CAULERPA LENTILLIFERA FERMENT EXTRACT FILTRATE
A gentle, fermented seaweed extract that helps calm irritation and boost hydration without clogging pores.
Irritation
low
Source
biotech
A gentle, probiotic-based exfoliant that helps smooth skin and support a healthy microbiome without harsh acids.
Irritation
low
Source
biotech
Humectant
LACTOBACILLUS/HYDROLYZED COLLAGEN FERMENT FILTRATE EXTRACT
A gentle, fermented collagen ingredient that may help hydrate and support the skin barrier, though research is still emerging.
Irritation
low
Source
biotech
A gentle, microbiome-friendly ingredient that helps hydrate and strengthen the skin barrier without irritation.
Irritation
low
Source
biotech
A gentle, fermented kelp extract that hydrates and soothes skin while supporting a healthy microbiome.
Irritation
low
Source
biotech
A gentle, fermented ingredient that helps hydrate and support a balanced skin microbiome without irritation.
Irritation
low
Source
biotech
A gentle, fermented watermelon extract that provides mild exfoliation and hydration, ideal for sensitive skin.
Irritation
low
Source
biotech
A gentle, fermented ingredient that may support skin hydration and a balanced microbiome, though research is still emerging.
Irritation
low
Source
biotech
A gentle probiotic ferment that may help hydrate and support a healthy skin microbiome, but research is still emerging.
Irritation
low
Source
biotech
A gentle, microbiome-friendly ferment that hydrates and soothes without irritation.
Irritation
low
Source
biotech
A gentle, biotech-derived ferment that helps hydrate and calm the skin while supporting a healthy barrier.
Irritation
low
Source
biotech
A gentle fermented pumpkin extract that lightly exfoliates and hydrates, ideal for sensitive skin looking for mild renewal.
Irritation
low
Source
biotech
Skin conditioning
LACTOBACILLUS/SCHIZOSACCHAROMYCES FERMENT FILTRATE
A gentle, probiotic-derived ferment that helps strengthen the skin barrier and support a healthy microbiome without irritation.
Irritation
low
Source
biotech
A gentle milk protein that helps hydrate and temporarily smooth the skin, but may not suit those with dairy sensitivities.
Irritation
low
Source
natural
Lactose is a gentle milk-derived sugar that hydrates and lightly exfoliates, making it a good option for sensitive or dry skin.
Irritation
low
Source
natural