Serine

Benefits
Hair ConditioningProtectionMoisturizing

What is Serine?

Serine is a non-essential amino acid, chemically known as 2-amino-3-hydroxypropanoic acid, found naturally in proteins like silk and human skin's natural moisturizing factor. Synthetically produced or derived from fermentation, it serves primarily in moisturizers, serums, shampoos, and conditioners. Functioning as a humectant, it draws moisture from the environment into the skin and hair, enhancing hydration. Its polar hydroxyl group enables water-binding, while amino and carboxyl groups contribute to conditioning by smoothing cuticles and reducing friction. In formulations, it stabilizes emulsions and improves texture, supporting skin barrier function without greasiness. Dermatological studies highlight its role in maintaining stratum corneum integrity, making it suitable for daily use across product types.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Fragrance ingredient
Contributes scent character and/or masks base odors, shaping the overall sensory experience of the formula (subject to allergen and IFRA considerations).
Hair conditioning
Improves softness, shine, and manageability by reducing friction and static; commonly achieved with cationic agents, silicones, oils, or conditioning polymers.
Skin conditioning agent
Maintains skin softness, smoothness, and flexibility.
Antistatic agent
Reduces static electricity and flyaways by improving surface conductivity, enhancing hair manageability and smoothness in conditioners and styling products.
Masking
Reduces perception of unpleasant odors or tastes by neutralizing them or covering them with more acceptable sensory notes.

Benefits

Supports skin hydration by binding water molecules.

Enhances hair softness and manageability.

Helps protect skin and hair from environmental stressors.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
People with dry or dehydrated skin seeking gentle hydration.
Anyone with known allergies to amino acids.
Individuals with frizzy or static-prone hair.
People sensitive to humectants in high-humidity environments.
Those looking for multifunctional conditioning in daily routines.
Those preferring anhydrous formulations without water-attracting agents.

Safety Notes

  • Rated low hazard by EWG with scores of 1.
  • Deemed safe for cosmetic use by expert reviews like CIR.

Frequently Asked Questions about Serine

What is serine in skincare?

A natural amino acid acting as a humectant to hydrate skin and condition hair.

Is serine safe for sensitive skin?

Yes, it has a low irritation profile and EWG score of 1.

Does serine clog pores?

No, it has a comedogenic rating of 0.