Is Diazolidinyl Urea Safe During Pregnancy and Breastfeeding? (2026 Guide)
Diazolidinyl Urea appears in a meaningful number of skincare and beauty formulas, which is exactly why this question comes up so often during pregnancy and breastfeeding. In the MamaSkin ingredient library, this ingredient is currently classified as low risk, and that risk band is based on the evidence summary and source set we maintain for ingredient-level screening. The goal here is not fear messaging. The goal is to help you understand where this ingredient sits in a conservative pregnancy-safety framework so you can make practical product decisions quickly.
Our scoring approach is ingredient-led and precautionary. That means we look at mechanism, exposure route, and available human or preclinical signals, then map that to a risk band that is consistent across the app and website. For Diazolidinyl Urea, the current evidence summary in our dataset is: Formaldehyde-releasing preservative; contact-allergy literature shows sensitisation but no reproductive toxicity.
At a glance: Diazolidinyl Urea is currently classed as low risk in MamaSkin's ingredient dataset.
What is Diazolidinyl Urea?
diazolidinyl urea is typically used for formula preservation, stability, or product performance.
Why MamaSkin marks diazolidinyl urea as low risk
Formaldehyde-releasing preservative; contact-allergy literature shows sensitisation but no reproductive toxicity. In our scoring model, this is treated as low risk in pregnancy-focused assessments.
Quick summary
- Current risk band in our data: low risk
- Why it is flagged this way: Formaldehyde-releasing preservative; contact-allergy literature shows sensitisation but no reproductive toxicity.
- Breastfeeding: this ingredient has no specific breastfeeding flag in our current dataset, but product-level formulation checks are still important.
Callout: evidence from our ingredient file
Ingredient: diazolidinyl urea
Risk band: low risk
Evidence sources listed in our dataset: PubMed, U.S. National Library of Medicine (NLM), FDA, EU CosIng, DermNet NZ
What this means in practice
For pregnancy skincare planning, this ingredient should not be viewed in isolation from the full INCI list. A product can contain one flagged ingredient and still differ substantially from another product containing the same ingredient, depending on concentration, vehicle, other actives, and use pattern. That is why this page gives ingredient-level context while the app remains the best place to run full product-level checks.
For breastfeeding, we use the dedicated breastfeeding columns in our ingredient data where available and apply practical handling advice in a conservative way. That usually means paying attention to application area, avoiding breast or nipple contact when relevant, and re-checking the exact formula currently in your hand because labels and regional formulas can change.
Product examples from our database
Want the full list? These are example products from our current snapshot, not every product we track. In the MamaSkin app you can search and scan many more products, including full brand ranges.
- 8.1.8 Beauty Formula Foaming Facial Cleanser For Oily And Sensitive Skin by 8.1.8 Beauty Formula (score 74, low risk)
- A Beautiful Life Botanical Moisturizer with Lavender and Mango Extracts by A Beautiful Life (score 75, low risk)
- acne.org Treatment (Benzoyl Peroxide – 2.5%) by acne.org (score 74, low risk)
- Acnes Oil Control Milk Cleanser by Acnes (score 71, low risk)
- Acnes White & Oil Control Whitening Cream by Acnes (score 70, low risk)
- Acqua Alle Rose Gel Esfoliante Quotidiano Purificante by Acqua Alle Rose (score 55, medium risk)
- Alejon Sunscreen Spray by Alejon (score 53, medium risk)
- Alejon Urea Cream 10% by Alejon (score 53, medium risk)
Important notes
- This article is informational only and is not medical advice.
- Formulations can change by market and over time.
- Always verify the current ingredient label before use.
Read next
- Formaldehyde and Formaldehyde-Releasing Preservatives in Pregnancy
- Ingredients to Avoid in Pregnancy (2026 Guide)
- Is Quaternium-15 Safe During Pregnancy? (2026 Guide)
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