Aspartic Acid
NMF amino acid – a component of the skin's natural moisturizing factor. Pregnancy-safe.
Evidence by route
Topical application
NMF amino acid. Supports stratum corneum hydration.
- Rawlings AV, Harding CR. Moisturization and skin barrier function. Dermatol Ther 2004. PMID 14728698
How to read tiers A–F
- BLimited evidence. One RCT or several controlled studies with limitations
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Combination, Oily, Sensitive
About this ingredient
Aspartic Acid (Asp, D) is an amino acid with an extra carboxyl group on the side chain, which makes it acidic and negatively charged at physiological pH. In skin, it is part of the natural moisturizing factor (NMF) of the stratum corneum and serves as a free amino acid in keratinocyte energy metabolism. Where it is used. Serums and emulsions for dehydrated skin, barrier recovery, mature-skin products containing amino acid complexes. Concentrations 0.5-3%. More commonly appears in blends with glycine, serine, alanine, and proline in comprehensive NMF formulas. In Spain: Sesderma Reti Age, Mesoestetic Stem Cell Active Growth Factor. Mechanism. The carboxyl side chain of aspartic acid binds water more firmly than neutral amino acids, raising stratum corneum hydration under low ambient humidity. It also buffers pH, maintaining the acidic skin barrier (pH 4.5-5.5). Provides substrate for glutamate synthesis (a neurotransmitter and glutathione component) and feeds the Krebs cycle in keratinocyte mitochondria. Evidence base. No isolated clinical trial of topical aspartic acid exists. Evidence base C-D through indirect NMF data (Rawlings 2004, Verdier-Sevrain 2007) and amino acid complexes in atopic dermatitis (Choi 2007). Aspartic acid does not carry standalone active load – it works synergistically with other NMF components. Safety. Pregnancy and breastfeeding – topical use is safe without restriction. Non-comedogenic, non-sensitizing, hypoallergenic. Tolerance profile is similar to glycine. CIR (2017) confirmed safety. Practical notes. In INCI lists, aspartic acid usually sits at position 5-10 within an amino acid complex. It is rarely used as a single ingredient. Compatible with every active without exception. Not to be confused with aspartame (methyl ester of aspartyl-phenylalanine) – a food sweetener with different properties and regulatory status.
Frequently asked questions
Is Aspartic Acid safe during pregnancy?
Aspartic Acid is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Aspartic Acid for?
Aspartic Acid suits: normal, dry, combination, oily, sensitive.
What is Aspartic Acid and what does it do in cosmetics?
NMF amino acid – a component of the skin's natural moisturizing factor.
Is Aspartic Acid comedogenic?
On the Fulton scale 0/5 – non-comedogenic. For acne-prone skin, a rating of 3 or higher suggests choosing an alternative.
What's the INCI name for Aspartic Acid?
The INCI name is Aspartic Acid. It may also appear as: L-Aspartic Acid.
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