What Is Chlorhexidine, and How Does It Actually Work?

Chlorhexidine isn't a new or trendy ingredient. It's been a hospital-grade antiseptic for more than half a century, and it's still what the NHS and hospitals reach for before surgery. That's the ingredient CS1000 and CS500 are actually built on.

What it is

Chlorhexidine is a synthetic antiseptic, developed in the 1950s and used ever since in surgical skin prep, wound cleansing, and dental care. It's sold under various trade names for medical use and is one of the most studied antiseptics available, decades of clinical use tend to do that.

How it actually kills bacteria

The molecule carries a positive charge, which draws it straight to the negatively charged walls of bacterial cells. Once attached, it disrupts the cell membrane, causing the contents to leak out, which kills the bacterium. At the concentrations used in skin and surface products, this happens quickly and works against a broad range of bacteria and fungi.

One property that matters more than most people realise: chlorhexidine binds to proteins in skin and stays active for 8 to 12 hours after application. That's not just a kill-on-contact ingredient, it keeps working well after you've sprayed it.

Why hospitals still use it

Guidelines from bodies like NICE recommend chlorhexidine-based antiseptic as a first-line option for preparing skin before surgery, specifically because it's effective against a broad spectrum of bacteria, including resistant strains like MRSA, and because it keeps working for hours rather than evaporating off immediately.

Why it's in CS1000 and CS500

The same properties that make it a surgical-prep standard make it a genuinely good choice for cosmetic and grooming tool hygiene: it kills a broad range of bacteria fast, it keeps working after the spray has dried, and it's been used safely on skin for decades. That's a meaningfully different claim than a generic "antibacterial" spray, which often just means added fragrance and alcohol.

What to know before using it

Chlorhexidine is generally well tolerated, but like any active ingredient, a small number of people can have a sensitivity or allergic reaction, usually mild contact irritation. If you notice redness or irritation where a chlorhexidine-based product has touched skin, stop use and check with a pharmacist or doctor.

FAQ

Is chlorhexidine safe to use on skin every day?
Yes, for the vast majority of people. It's used in hospitals for skin prep and in dental mouthwashes long-term. Mild sensitivity is possible but uncommon, and CS1000 and CS500 use it at concentrations suited to daily tool hygiene, not surgical-strength doses.

What's the difference between chlorhexidine and regular alcohol-based sanitiser?
Alcohol kills bacteria on contact but evaporates and stops working almost immediately. Chlorhexidine binds to surfaces and skin proteins and keeps working for 8 to 12 hours after application.

Why don't more consumer products use chlorhexidine if it's this effective?
It's more expensive and more heavily regulated to formulate with than generic alcohol or fragrance-based antibacterial claims, which is exactly why a lot of "antibacterial" sprays on the market aren't built on a real medical-grade active ingredient.

Sources: Mayo Clinic, "Chlorhexidine (topical application route)", clinical reference, 2026. Pang et al., "Microneedle-Mediated Permeation Enhancement of Chlorhexidine Digluconate", peer-reviewed, referencing NICE guidelines on surgical antisepsis.