Kiehl's
Kiehl's Ultra Facial Moisturizing Cream with Squalane
Low risk74/100
Kiehl's
Powerful-Strength Vitamin C Serum
Some ingredients carry a low-risk flag. Read the formulation context before deciding.
15 of 17 ingredients rated2 not assessed
Is it suitable during pregnancy?
MamaSkin rates the recorded formula for Kiehl's Powerful-Strength Vitamin C Serum as Low risk (78/100). Review the ingredient context and any manual-review explanation before deciding.
Why this rating?
The recorded formula includes 2 ingredient entries with risk flags: Dimethicone (Low risk), Dimethicone Crosspolymer (Low risk). These are ingredient-level flags; they do not replace the stored product assessment or account for every formulation detail.
15 of 17 ingredient entries on this page have a recorded score, evidence summary and source text. 2 entries do not have all of those fields. Unmatched or unrated entries are marked Not assessed in grey; missing evidence does not establish safety.
How we assess productsIngredient breakdown
The recorded formula, with evidence behind each rating. Unmatched ingredients are marked Not assessed in grey.
Ingredient ratings and evidence
Higher-risk flags first. Open an ingredient for evidence.
Dimethicone
Low risk
Dimethicone is a silicone polymer used as a skin protectant and slip/conditioning agent. It is considered inert with minimal dermal absorption; the main practical issues are cosmetic (feel) and occasional irritation in very sensitive users. It is not a pregnancy-specific concern in topical cosmetic use.
Sources: CIR: Amended Safety Assessment of Dimethicone, Methicone, and Substituted-Methicone Polymers as Used in Cosmetics https://cir-safety.org/supplementaldoc/amended-safety-assessment-dimethicone-methicone-and-substituted-methicone-polymers-2
Dimethicone Crosspolymer
Low risk
This ingredient is a dimethicone crosspolymer covered by CIR's crosspolymer assessment. CIR concluded the reviewed crosspolymers safe as used in cosmetics. That conclusion is based on polymer chemistry and cosmetic-use safety data, not human pregnancy studies for every named crosspolymer. MamaSkin retains Low Risk; finished-product irritation remains formulation-dependent.
Sources: CIR: Safety assessment of dimethicone crosspolymers https://www.cir-safety.org/supplementaldoc/safety-assessment-dimethicone-crosspolymers-used-cosmetics
Citrus Aurantium Dulcis Peel Oil/Orange Peel Oil
Not assessed
No matched ingredient rating is available yet. Not assessed does not mean safe or unsafe.
Citrus Limon Peel Oil/Lemon Peel Oil
Not assessed
No matched ingredient rating is available yet. Not assessed does not mean safe or unsafe.
Propylene Glycol
No known risks
Propylene glycol is a common solvent and humectant with a long history of use; it is not considered a pregnancy or breastfeeding concern in topical cosmetics, though some individuals may experience irritation in leave-on products.
Sources: CIR; EU/UK Cosmetics Regulation
Show all 17 ingredients
Glycerin
No known risks
Glycerin is a widely used humectant that supports hydration and the skin barrier, with a long safety record and no known pregnancy or breastfeeding concerns in topical cosmetic use.
Sources: CIR; EU/UK Cosmetics Regulation
Ascorbic Acid
No known risks
Vitamin C antioxidant used to support brightness and photoprotection; functions as an antioxidant/pH adjuster in cosmetic formulas. No pregnancy-specific contraindications are identified for topical cosmetic use.
Sources: CIR (Ascorbic Acid); PubMed (NLM)
Cetyl Peg/Ppg-10/1 Dimethicone
No known risks
A silicone polyether used mainly as an emulsifier and conditioning ingredient. The Cosmetic Ingredient Review concluded that this ingredient is safe in current cosmetic use. Concentrated-material tests found limited transient irritation, while a finished cosmetic containing 15% was non-irritating in human patch testing; no pregnancy- or breastfeeding-specific concern is identified for normal topical use.
Sources: CIR: Safety Assessment of Polyoxyalkylene Siloxane Copolymers as Used in Cosmetics (Final Report 2014) https://cir-safety.org/sites/default/files/ROPSIL_122014%20_FAR.pdf
Ascorbyl Glucoside
No known risks
A stable vitamin C derivative used as an antioxidant and skin-conditioning ingredient. The Cosmetic Ingredient Review concluded that ascorbyl glucoside is safe in current cosmetic use; normal topical exposure does not identify a pregnancy- or breastfeeding-specific concern.
Sources: CIR: Safety Assessment of Ascorbyl Glucoside and Sodium Ascorbyl Glucoside https://www.cir-safety.org/supplementaldoc/safety-assessment-ascorbyl-glucoside-and-sodium-ascorbyl-glucoside-used-cosmetics
Lauroyl Lysine
No known risks
Amino-acid-derived conditioning and slip ingredient used especially in powders and colour cosmetics. Reviewed cosmetic safety sources support normal topical use, with no pregnancy- or breastfeeding-specific topical signal identified in the material reviewed.
Sources: CIR: Safety Assessment of Amino Acid Alkyl Amides as Used in Cosmetics; EU CosIng / cosmetics regulatory inventory
Boron Nitride
No known risks
An inert inorganic powder used to improve slip, texture and soft focus in makeup. Cosmetic safety reviewers concluded that cosmetic-grade boron nitride is safe in current cosmetic use. No pregnancy-specific concern is identified for normal skin application; as with cosmetic powders generally, avoid deliberately inhaling airborne powder or airbrush spray.
Sources: CIR: Safety Assessment of Boron Nitride as Used in Cosmetics https://www.cir-safety.org/supplementaldoc/safety-assessment-boron-nitride-used-cosmetics-0
Hydroxyethylpiperazine Ethane Sulfonic Acid
No known risks
HEPES is a zwitterionic pH buffer. Its function and expected topical exposure do not indicate a reproductive or developmental concern in normal cosmetic use.
Sources: European Commission CosIng; peer-reviewed biochemical literature on HEPES.
Adenosine
No known risks
Skin-conditioning ingredient commonly used in leave-on skincare. Reviewed cosmetic safety sources support normal topical use, with no pregnancy- or breastfeeding-specific topical signal identified in the material reviewed.
Sources: CIR: Safety Assessment of Adenosine Ingredients as Used in Cosmetics; EU CosIng / cosmetics regulatory inventory
Hydrolyzed Hyaluronic Acid
No known risks
Humectant and skin-conditioning ingredient in the hyaluronate family. Reviewed cosmetic safety sources support current cosmetic use, with no pregnancy- or breastfeeding-specific topical concern identified in the material reviewed.
Sources: CIR: Safety Assessment of Hyaluronates as Used in Cosmetics; EU CosIng / cosmetics regulatory inventory
Limonene
No known risks
Limonene is a common fragrance component used at low levels in cosmetics; it is not a pregnancy-specific concern in topical use, but it is a recognised fragrance allergen and may trigger irritation or sensitisation in some people, especially if the product oxidises over time.
Sources: EU/UK cosmetics (fragrance allergen labelling); IFRA; toxicology reviews
Citral
No known risks
A lemon-scented mixture of the aldehydes geranial and neral used in fragrance. Citral is a recognised skin sensitiser, but current cosmetic concerns relate to allergy and concentration rather than a pregnancy-specific hazard from normal topical use.
Sources: European Commission: Fragrance allergens labelling https://single-market-economy.ec.europa.eu/sectors/cosmetics/cosmetic-products-specific-topics/fragrance-allergens-labelling_en; SCCS fragrance-allergen opinions
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate.
No known risks
Antioxidant and stabilizer used to protect cosmetic formulas from oxidation. Reviewed cosmetic ingredient references do not identify a pregnancy- or breastfeeding-specific concern for normal topical cosmetic use.
Sources: CIR cosmetic ingredient safety references for hindered phenolic antioxidants; EU CosIng / cosmetics regulatory inventory
Full recorded ingredient list
Dimethicone, Propylene Glycol, Glycerin, Ascorbic Acid, Cetyl Peg/Ppg-10/1 Dimethicone, Dimethicone Crosspolymer, Ascorbyl Glucoside, Lauroyl Lysine, Boron Nitride, Hydroxyethylpiperazine Ethane Sulfonic Acid, Adenosine, Hydrolyzed Hyaluronic Acid, Limonene, Citrus Aurantium Dulcis Peel Oil/Orange Peel Oil, Citrus Limon Peel Oil/Lemon Peel Oil, Citral, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate.
Ingredient ratings refreshed 1 October 2026. Formulas vary by market and can change. Always compare with your packaging.
Questions about this assessment
Why does Kiehl's Powerful-Strength Vitamin C Serum have a Low risk rating?
The recorded formula includes 2 ingredient entries with risk flags: Dimethicone (Low risk), Dimethicone Crosspolymer (Low risk). These are ingredient-level flags; they do not replace the stored product assessment or account for every formulation detail. Incomplete ingredient documentation does not establish safety; see the coverage answer and grey entries below.
Has every ingredient in Kiehl's Powerful-Strength Vitamin C Serum been assessed?
15 of 17 ingredient entries on this page have a recorded score, evidence summary and source text. 2 entries do not have all of those fields. Unmatched or unrated entries are marked Not assessed in grey; missing evidence does not establish safety.
Does this assessment apply to my Kiehl's Powerful-Strength Vitamin C Serum?
Only if the ingredient list on your packaging matches the recorded formula shown here. Formulas can differ by market and change over time. Compare the full list, not just the product name; report a mismatch if it differs.
Does this pregnancy assessment also establish breastfeeding suitability?
No. This page presents a pregnancy-focused product assessment. Do not infer a breastfeeding conclusion from its score or label; breastfeeding requires a separate assessment of the formula and how it is used.
