Dyna-Hex 4 is a 4% chlorhexidine gluconate antiseptic wash used to reduce bacteria on your skin before surgery, lowering the risk of surgical site infections. Most surgical teams will ask you to shower with it at least twice: once the night before surgery and again the morning of surgery. The process is straightforward, but the details matter. Skipping steps or applying products afterward can reduce its effectiveness.
When and How Often to Shower
The standard schedule is two showers: one the evening before your procedure and one the morning of surgery. Some surgical teams request a third shower the evening before that, depending on the type of operation. Follow whatever schedule your surgeon’s office provides, but if you only received the bottle without specific timing instructions, the night-before and morning-of routine is the widely accepted minimum.
Step-by-Step Shower Instructions
Start by washing your hair with your regular shampoo and rinsing it completely. You can also wash your face with your normal face wash at this point. Get all of that done first, because once you begin applying Dyna-Hex 4 to your body, you should not follow up with regular soap.
Turn off the water. Apply the Dyna-Hex 4 liberally to your entire body from the jawline down. Use your hands or a clean washcloth to spread it across your skin, paying extra attention to the area where your incision will be. Let the product sit on your skin for at least two minutes before rinsing. This contact time is critical. The antiseptic needs those minutes to bind to your skin and begin killing bacteria.
After rinsing, repeat the process: apply the wash again, lather for another two minutes, then rinse thoroughly. This two-round approach is what the product labeling specifically calls for in preoperative skin preparation. Pat yourself dry with a clean towel. On the morning of surgery, follow the same sequence again.
If Your Surgery Involves the Scalp or Head
Some procedures require washing your scalp with the antiseptic as well. UW Medicine recommends diluting the Dyna-Hex with an equal amount of water before applying it to your scalp, then leaving it on while you wash the rest of your body. Only do this if your surgical team specifically asks you to. For most surgeries, keeping the wash from the jawline down is sufficient.
Where Not to Apply It
Keep Dyna-Hex 4 away from your eyes, ears, nose, mouth, and genital area. It is designed for external skin only and can cause serious irritation on mucous membranes. If it accidentally gets into your eyes, flush them with water right away. For the genital area, use your regular mild soap separately before starting the Dyna-Hex routine.
What to Avoid After Your Shower
This is the step most people trip up on. After drying off, do not apply any of the following:
- Lotion or moisturizer
- Deodorant or antiperspirant
- Makeup or powder
- Perfume or cologne
- Body oil or cream
These products can create a barrier on your skin that interferes with the chlorhexidine’s ability to keep working after you’ve rinsed. The antiseptic binds to your skin’s outer layer and continues to suppress bacteria for hours, but only if nothing blocks that bond. If you absolutely need to use a product (such as a prescribed topical medication), check that it is labeled “chlorhexidine compatible.” Also, do not go back over your body with regular soap after rinsing off the Dyna-Hex. That defeats the purpose.
Dress in freshly laundered clothes after your shower, and sleep on clean sheets the night before surgery. The goal is to keep your skin as free from new bacteria as possible between your wash and the operating room.
Other Prep Tips
Do not shave the surgical area before your procedure. Shaving creates tiny nicks in the skin that can harbor bacteria, which is exactly what you’re trying to prevent. If hair removal is needed, your surgical team will handle it at the hospital with clippers designed to avoid skin breaks.
Keep your nails trimmed and clean. Remove any nail polish or acrylic nails if your surgical team requests it, since monitoring devices on your fingertips need direct contact with your nail bed during the procedure.
Signs of an Allergic Reaction
Chlorhexidine allergies are uncommon but can be serious. Stop using Dyna-Hex 4 and contact your surgical team if you experience any of the following after application:
- Hives or rash that spreads beyond mild redness at the application site
- Facial swelling
- Wheezing or difficulty breathing
Mild warmth or slight tingling during application is normal. A persistent, worsening rash or any breathing difficulty is not. If you’ve had a reaction to chlorhexidine products in the past, let your surgeon know before they prescribe Dyna-Hex 4 so they can recommend an alternative antiseptic wash.