A New Way to Treat Molluscum Contagiosum

For years, treating molluscum contagiosum meant going to a doctor's office for procedures like freezing (cryotherapy) or scraping (curettage) — or just waiting months for bumps to go away on their own. Zelsuvmi (berdazimer topical gel, 10.3%) changed that. It's the first FDA-approved topical treatment you can use at home.

But how does a gel applied to the skin actually fight a virus? Let's break it down in plain English.

The Basics: What's in Zelsuvmi?

The active ingredient in Zelsuvmi is berdazimer sodium — a molecule designed to release nitric oxide (NO) when applied to the skin. Berdazimer is classified as a nitric oxide-releasing agent.

Nitric oxide is a gas that your body naturally produces. It plays roles in blood vessel regulation, immune defense, and fighting infections. Scientists discovered that nitric oxide has powerful antiviral properties, and Zelsuvmi was designed to deliver it directly to where the virus lives — in the skin cells of molluscum bumps.

Step by Step: How Zelsuvmi Fights the Virus

Here's what happens when you apply Zelsuvmi to a molluscum lesion:

Step 1: You Mix and Apply the Gel

Zelsuvmi comes as two tubes — Tube A (berdazimer gel) and Tube B (hydrogel). When you mix them together on the dosing guide, you activate the formulation. The mixed gel is then applied directly onto each molluscum bump. For full application instructions, see our dosage and usage guide.

Step 2: Nitric Oxide Is Released

Once the mixed gel contacts the skin, berdazimer begins releasing nitric oxide. The NO penetrates into the skin where the molluscum contagiosum virus (MCV) is replicating inside cells.

Step 3: Nitric Oxide Attacks the Virus

Nitric oxide fights the molluscum virus through multiple mechanisms:

• Blocks viral proteins: NO interferes with enzymes and proteins the virus needs to function. Without these proteins, the virus can't maintain its life cycle.
• Damages viral DNA: NO creates reactive nitrogen species that can directly damage the genetic material of the virus, making it unable to reproduce properly.
• Prevents viral replication: By disrupting both the viral proteins and DNA, NO stops the virus from making copies of itself and spreading to new skin cells.

Step 4: Lesions Begin to Clear

Over the course of treatment (up to 12 weeks of daily application), the combined antiviral effects of nitric oxide work to clear the molluscum bumps. Some lesions may clear faster than others, and complete clearance may take the full treatment course.

Why Nitric Oxide?

Nitric oxide is a uniquely versatile molecule in the body's defense system. Here's why it's such a smart choice for fighting molluscum:

• Broad-spectrum antiviral: NO doesn't target just one virus — it has activity against many types of viruses. This makes it effective against the molluscum contagiosum virus specifically.
• Multi-pronged attack: Unlike some antivirals that target a single step in the viral life cycle, NO disrupts multiple processes simultaneously. This makes it harder for the virus to develop resistance.
• Naturally occurring: Your body already produces nitric oxide as part of its immune response. Zelsuvmi essentially delivers a concentrated, targeted dose of something your body already uses to fight infections.
• Topical delivery: Because NO can be released directly at the site of infection, it works where it's needed without affecting the rest of the body.

What Makes Zelsuvmi Different from Other Treatments?

Understanding the mechanism helps explain why Zelsuvmi is unique:

The key difference: Zelsuvmi is the only FDA-approved at-home option that directly targets the virus with an antiviral mechanism. Other at-home options (like imiquimod) work indirectly by boosting the immune system, and in-office procedures destroy the lesions physically without directly addressing the virus.

For more on alternative treatments, read our guide on alternatives to Zelsuvmi.

The Two-Tube System: Why You Need to Mix

You might wonder why Zelsuvmi requires mixing two tubes every time. The answer is chemistry:

• Stability: Berdazimer needs to be kept separate from the hydrogel until the moment of use. If pre-mixed, the gel would start releasing nitric oxide in the tube — losing its effectiveness before it reaches your skin.
• Consistent dosing: Mixing fresh each time ensures you get a full, effective dose of nitric oxide with every application.
• Safety: The two-tube system prevents accidental overexposure to nitric oxide and keeps each component stable during storage.

It adds an extra step to your routine, but it's what makes the medication work properly.

Does It Work for Everyone?

Zelsuvmi works for many patients, but it's not a guaranteed cure for everyone:

• Clinical trials showed meaningful clearance of molluscum lesions compared to placebo
• Some patients may see partial clearance rather than complete resolution
• New bumps can still appear during treatment (from virus already present in the skin before treatment started)
• The full 12-week course may be necessary for best results

If Zelsuvmi doesn't fully clear your molluscum, your doctor may recommend combining it with other approaches or switching to an in-office treatment.

Is It Safe?

Zelsuvmi has been studied in clinical trials and is FDA-approved for patients 1 year and older. The most common side effects are local skin reactions:

• Stinging or burning at the application site (19%)
• Redness (12%)
• Itching (6%)

These are generally mild and temporary. Serious side effects are rare. For a complete breakdown, see our side effects guide.

Zelsuvmi has no known major drug interactions, though you should always tell your doctor about other medications and topical products you use. Learn more in our drug interactions guide.

The Science Is Promising

Zelsuvmi represents a genuinely new approach to treating a common condition. By harnessing nitric oxide — a molecule the body already uses to fight infections — it delivers targeted antiviral therapy directly to molluscum lesions at home.

If you're considering Zelsuvmi, talk to your doctor about whether it's the right option for you or your child. And when you're ready to fill your prescription, check out how to find a pharmacy with Zelsuvmi in stock.