Citrulline

Benefits
Hair GrowthHair ConditioningAnti AgingProtectionPore ShrinkingHair Loss PreventionMoisturizing

What is Citrulline?

Citrulline is a non-essential amino acid with the chemical structure (2S)-2-amino-5-(carbamoylamino)pentanoic acid. It occurs naturally in foods like watermelon and is produced synthetically for use in cosmetics. Primarily categorized as a skin conditioning agent, it appears in moisturizers, serums, shampoos, and conditioners. In formulations, citrulline acts as a humectant, attracting and binding water to the skin and hair shafts to promote softness and flexibility. It also contributes antistatic properties in hair products, reducing frizz. By participating in the conversion to arginine, it supports nitric oxide production, which may enhance microcirculation upon topical application, aiding skin and scalp vitality without causing buildup.

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

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Skin conditioning agent
Maintains skin softness, smoothness, and flexibility.

Benefits

Enhances skin and hair moisturizing by drawing in hydration

Supports hair conditioning for smoother texture

Contributes to anti-aging effects through improved vitality

Who It's For

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

Who May Benefit Who Should Avoid
Individuals with dry or dehydrated skin seeking hydration
Persons with rare amino acid sensitivities
People experiencing hair dryness or frizz
Individuals allergic to watermelon-derived ingredients
Those incorporating anti-aging or protective routines
Anyone preferring to patch test new actives first

Safety Notes

  • Considered safe for cosmetic use by regulatory reviews
  • Low potential for irritation in typical concentrations

Frequently Asked Questions about Citrulline

What is citrulline in cosmetics?

A humectant amino acid that hydrates skin and conditions hair.

Is citrulline safe for sensitive skin?

Yes, it shows low irritation potential from safety assessments.

Can citrulline help with dry hair?

It aids moisture retention and smoothness in hair products.