commonly use as lye-free hair relaxer

Guanidine carbonate is a multifunctional ingredient in cosmetic formulations, primarily valued for its ability to modify protein structures and stabilize formulations. Below is a detailed breakdown of its role in cosmetics, including formulation tips, mechanisms of action, and safety considerations:

1. Hair Care Applications

a. Hair Straightening/Relaxing Treatments

• Mechanism of Action:

  • Guanidine carbonate is a strong alkaline agent (pH ~11–12) that disrupts the disulfide bonds in keratin (hair’s structural protein). This breaks the hair’s natural curl pattern, allowing it to be reshaped into a straighter form.

  • Unlike sodium hydroxide (lye), guanidine carbonate is less irritating but still effective for "no-lye" relaxers.

• Formulation Guidelines:

  • Concentration: Typically used at 5–10% in relaxer creams or gels.

  • Combination with Other Agents:

    • Often paired with calcium hydroxide (activator) to generate heat and enhance bond-breaking efficiency.

    • May include conditioning agents (e.g., silicones, oils) to counteract dryness from the alkaline process.

  • pH Adjustment: Maintains a high pH (11–12) to ensure effective protein denaturation.

• Product Types:

  • Cream relaxers, lotions, or gels for curly or coily hair textures.

b. Hair Dyes and Colorants

• Acts as a pH adjuster or alkalizing agent in oxidative hair dyes to facilitate dye penetration into the hair shaft.

2. Skin Care Applications

a. Stabilizer and pH Adjuster

• Buffering Agent: Helps maintain the pH of formulations (e.g., creams, serums) in the alkaline range.

• Preservative Booster: Enhances the efficacy of preservatives in water-based products.

b. Depilatory Creams

• Mechanism: Breaks down keratin in hair shafts, similar to its action in hair relaxers, to weaken hair for easy removal.

• Formulation: Used at lower concentrations (2–5%) compared to hair relaxers.

3. Nail Care

• Nail Hardening Treatments:

  • Strengthens brittle nails by cross-linking keratin proteins.

• Cuticle Softeners:

  • Softens cuticles for easier grooming.

4. Formulation Considerations

a. Compatibility

• Synergistic Ingredients:

  • Urea or Ammonium Thioglycolate: Enhances protein denaturation in depilatories or relaxers.

  • Emollients (e.g., Shea Butter): Counteract dryness caused by alkaline formulations.

• Avoid Incompatibilities:

  • Strong acids (causes decomposition).

  • Oxidizing agents (risk of reaction).

b. Stability

• pH Sensitivity: Formulations must be stored in airtight containers to prevent CO₂ absorption, which can lower pH and reduce efficacy.

• Temperature: Store in cool conditions to prevent degradation.

c. Rheology Modifiers

• Thickeners like carbomers or cellulose gums are often added to create a creamy texture for ease of application.

Below is an example “no‐lye” hair relaxer formulation that uses guanidine carbonate as the activator. This formulation is provided for informational purposes only and should be handled, tested, and modified by experienced cosmetic chemists under controlled conditions. Improper handling or use of strong alkaline chemicals can cause serious injury. Always perform small‐scale trials and verify pH (targeting around 12–13 in the working mix) before any application.

There are two separate components—a Base Cream (which supplies the alkaline component) and an Activator (which contains guanidine carbonate). They are stored separately and mixed immediately before use.

Component A – Base Cream

(Designed to supply calcium hydroxide and provide a protective, emollient matrix)

Procedure for A:
– In a heated vessel (about 70–75°C), disperse the calcium hydroxide into a portion of the deionized water.
– Add the emulsifying wax and cetearyl alcohol, then incorporate mineral oil and petrolatum with vigorous stirring.
– Once the mixture is homogeneous, cool to room temperature and add the conditioning agent, xanthan gum, preservative, and fragrance.

Component B – Activator

(Supplies guanidine carbonate to react with the base, forming the active relaxing species)

Procedure for B:
– Dissolve guanidine carbonate in deionized water.
– Add propylene glycol and aloe vera extract, stirring until fully dissolved.
– Finally, incorporate EDTA and the preservative.

Usage Instructions

1. Storage: Keep Components A and B in separate, well‐labeled, airtight containers.
2. Mixing: When ready to use, blend equal parts (by weight) of Component A and Component B. This mixing initiates the reaction between calcium hydroxide and guanidine carbonate, generating the active relaxing agent (guanidine hydroxide) along with by‐products (e.g. calcium carbonate).
3. Application: Apply the freshly mixed relaxer evenly to the hair, avoiding direct scalp contact as much as possible. Typically, leave on for 15–30 minutes—but always perform a strand test first.
4. Neutralization & Rinse: After the processing time, thoroughly rinse the hair and apply a neutralizing shampoo to halt the chemical reaction.
5. Post‐Treatment: Follow with a deep conditioning treatment to restore moisture.

Use: for hair straightening products

Mixing method: Mix in water

Product characteristics: white crystalline powder

Solubility: can dissolve in water

Storage: can be stored at room temperature Protected from sunlight and heat.

INCI Name : Guanidine Carbonate