Chlorhexidine Dihydrochloride

What is Chlorhexidine Dihydrochloride?

Chlorhexidine dihydrochloride is the dihydrochloride salt form of chlorhexidine, a synthetic bisbiguanide compound developed as a broad-spectrum antiseptic. In cosmetics, it belongs to the antimicrobial and preservative category, primarily appearing in oral care formulations like mouthwashes and toothpastes, as well as some rinse-off skin products. It functions by binding to negatively charged bacterial cell surfaces, disrupting their membranes, and inhibiting enzyme activity, which prevents microbial growth and helps maintain product integrity. This cationic molecule remains active over a wide pH range, making it effective against Gram-positive and Gram-negative bacteria, yeasts, and some viruses. Typical concentrations are low to minimize potential interactions with other ingredients, and it supports product stability without altering texture or scent significantly.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 4 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Biocide
Destroys or inhibits harmful organisms to preserve products.
Oral care agent
Supports oral hygiene performance (cleaning, freshening, plaque control, sensitivity support) in toothpaste, mouthwash, and related products.
Preservative
Protects the product from microbial contamination during storage and use, helping maintain safety, stability, and shelf life.
Antimicrobial agent
Helps limit growth of bacteria and other microbes on skin or in the formula; may be used for product protection, odor control, or targeted antimicrobial effects.

Benefits

Supports product preservation by limiting microbial contamination during use.

Aids oral care products in maintaining hygiene performance like cleaning and freshening.

Provides antimicrobial effects to control odor and bacteria in formulas.

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 using mouthwashes or toothpastes for daily oral routine support.
Those with known hypersensitivity to chlorhexidine or bisguanides.
Users of rinse-off products needing microbial protection.
Individuals prone to allergic contact reactions.
People seeking stable, contamination-free cosmetic formulations.
Users experiencing mucosal or skin irritation from antiseptics.

Safety Notes

  • Potential for skin sensitization or irritation at higher exposure levels.
  • Rinse thoroughly to reduce residue-related concerns.

Frequently Asked Questions about Chlorhexidine Dihydrochloride

What products contain chlorhexidine dihydrochloride?

Commonly found in mouthwashes, toothpastes, and some rinse-off antimicrobial cosmetics.

How does it work as a preservative?

It disrupts microbial cell membranes to inhibit growth and protect formulas from contamination.

Is it suitable for sensitive skin?

May irritate sensitive individuals; patch test or consult if history of reactions exists.